Bmw Engine Overheating What To Do?

What Should You Do If Your BMW is Overheating? Vehicles usually overheat in extremely hot weather, so what should you do if your BWM is overheating? Fortunately, today’s feature sophisticated cooling systems, including engine temp sensors and computer-monitored electric fans, designed to keep your engine running optimally no matter what the season.

But overheating is still a possibility, and it’s important to know what to do in the event it happens to you.
If you see that your engine is starting to overheat, you’ll want to turn off the AC and turn on the heat to get the heat away from your engine.
This reduces the burden on the cooling system.
If that doesn’t work, pull over and turn off the engine.

Once the car has cooled, open the hood and check the coolant. You can do your part to prevent further damage to your BMW’s engine if you can get it cooled down before it overheats and the engine fails. Then, you can get the car safely to your trusted mechanic.
View full answer

Contents

1 What is the fastest way to cool down a car engine?
2 How much does it cost to fix an overheating BMW?
- - 2.0.1 How do I know if my engine is damaged from overheating?
3 What is the fastest way to cool an engine down?
- 3.1 How does a BMW cooling system work?

What does it mean when a BMW overheats?

Possible reasons behind a BMW overheating – Being low on coolant is the most common reason a BMW overheats. This is the result of a coolant leak. The technicians at Steve’s Auto Repair & Tire are able to look for and address coolant leaks. Overheating can also indicate a thermostat issue.

If the thermostat doesn’t open, coolant isn’t able to flow to where it needs to go. A car could also overheat due to an electrical component, such as the electric cooling fan and electric cooling fan controller. Even a module or computer may be experiencing an issue that prevents the cooling fan from turning on.

We have worked on vehicles that had functioning cooling fans that weren’t spinning fast enough to pull air through.
View full answer

How long does it take for a BMW engine to cool down?

What to Do If Your Car Overheats: 5 Must-Know Steps – By jibarra | Posted in Uncategorized on Monday, May 21st, 2018 at 3:35 pm When the mercury begins to rise outside, it’s common for car engines to get overly toasty too. Thankfully, there are plenty of things you can do to make sure a temporary jump in temperature doesn’t lead to long-lasting trouble. To help you know what to do if your car overheats, here are 5 easy steps.

First, always carry an extra bottle of coolant (also called antifreeze) in your car, as well as a jug of water. Engines typically overheat because the coolant’s low, so topping it off will usually solve the problem. Failing that, water will also temporarily do the trick. Plus, that water could be a lifesaver on long, sweltering summer drives. Just don’t drink it all.
When you see the temperature gauge creeping into the red or a notification light glowing, immediately turn off your air conditioner (since the AC puts a lot of strain on your engine).
If the problem persists, crank your heater up to full blast. It could make the next few miles a pretty brutal experience, but the transfer of heat away from the engine might just save its life.
Should the preceding steps fail, pull over as soon as you can. Turn off the engine. If you can pop the hood from the driver’s seat, do so — but don’t risk opening it by hand until the engine has cooled, especially if you see steam wafting off the engine. It typically takes a solid 30 minutes for an engine to cool down enough for it to be safe to handle. If you’d rather let a professional handle the problem, it’s time to call for a tow truck.
Once the engine has cooled, check the coolant tank. It’s usually a translucent plastic tank near the radiator. If the coolant tank is empty, you may have sprung a leak. Take a quick look under the car. If you notice a drip or puddle, chances are the coolant tank is leaking.

If you do have a leak, carefully open the radiator cap. Place a cloth over the radiator cap to protect your hand, and tilt the cap away from you as it opens. Refill the cooled radiator with your spare coolant or water. Do not pour cold water into a still-hot radiator — it could cause the engine block to crack due to the sudden change in temperature.

If you absolutely have to add water while the engine is still warm, pour slowly while the engine is running in neutral or park. Note that most cars require a 50/50 mix of coolant with water to prevent overheating, so you won’t be able to drive indefinitely with nothing but water. If you don’t have coolant on hand when your car overheats, make sure to add a comparable amount of coolant as soon as possible.

If the coolant tank is full, the problem may be electrical or mechanical in nature, in which case a tow to the nearest repair shop is definitely in order. A leaking hose, worn or broken fan belt, bad water pump, or malfunctioning thermostat may be the culprit.
View full answer

How long should I let my car sit after overheating?

Wait until the engine completely cools — at least 30 minutes. You might be able to speed up the cooling process if you can pop the hood with a latch located inside the car cabin. But, do not touch or attempt to open the hood until the engine is completely cool.
View full answer

What is the fastest way to cool down a car engine?

Engine Cooling System If your car is overheating, it can be very serious. You shouldn’t continue to drive if you see the temperature gauge has moved towards the “hot” side. Your car may not immediately explode or anything like that, but driving with an overheating engine can cause serious damage to your vehicle.

It’s better to pull over and deal with it right away instead of risking very expensive repairs later. There are a number of things that can cause your engine to overheat. Some of these are fairly common issues, especially on a hot summer day in the Phoenix, Tempe and Chandler areas. Improperly Circulating Coolant If the water/antifreeze mixture isn’t circulating correctly, the engine will start to overheat.

This mixture keeps your engine cool during the hot months and prevents it from freezing during the cold months. Be sure to check it regularly to avoid this. Even if you don’t have any leaks, over time it can evaporate. You can add about half a cup of water to a low antifreeze tank to cool down your engine and get you to an auto shop.

There’s A Leak If your water/antifreeze levels are constantly low, there’s a leak in your cooling system somewhere,
If you’re experiencing this, make an appointment with us today.
We’ll track down the leak and give you an affordable estimate for the repair.
A Hose Needs Replacing Over time, the hoses that circulate your coolant may become blocked or detached.

While it may not be completely blocked up, even a partial blockage can prevent the proper amount of coolant from circulating. Again, this is something we can check for during an inspection here in our shop. Other Causes If the levels of water and antifreeze appear normal, there may be a more serious malfunction with your engine.

Turn off the air conditioner. Running the A/C puts a heavy load on your engine.Turn on the heater. This blows some excess heat from the engine into the car. While it’s not ideal on a hot summer day (which is when most vehicles tend to overheat), it does help cool the engine down.Put your car in neutral or park and then rev the engine. This makes the fan and the water pump work faster, which pulls more air and more water through your car’s radiator. This increased circulation cools down the engine.Pull over and open the hood. This releases the heat and lets air circulate through the hot engine. Just be careful when opening the hood—hot steam may come blasting out.

And finally, NEVER attempt to remove the radiator cap while the engine is hot, It can result in serious burns all over your body as the hot coolant sprays forth under tremendous pressure. If you have concerns about any of the things considered in the article, Elite Auto Repair is always ready to help.
View full answer

Will my engine be OK after overheating?

THE DOS AND DON’TS OF WHAT TO DO WHEN YOUR CAR OVERHEATS – Uh-oh! It’s happened! Now what? Here’s your step-by-step game plan of what to do:

DO Immediately turn off the air conditioner. This will help reduce stress on the engine and cooling system.
DO turn up the heat. Huh? Crank the heat? Yes! This will help divert heat away from the engine.
DO find a safe place to pull over and shut off the engine.
DO allow the engine to cool for at least 15 minutes. Keep an eye on the gauge (if equipped), waiting until it moves back to the normal range.
DO take out your phone. You need to get your car to a repair shop, so call a friend or a tow truck.
DO add radiator fluid (if you have it). A quick top-off could help protect your engine from further damage.
DO carefully restart the engine (if your car isn’t being towed). Drive to the nearest repair shop, all the while keeping an eye on the gauge/light. If it begins to creep up/illuminate again, pull over and let it cool.

Knowing what to do when your car overheats is important. So is knowing what not to do:

DON’T just continue on to your destination. Your overheated engine may still be running, but it’s not fine. You risk costly damage to your engine if you keep driving.
DON’T panic. Your engine may have lost its cool, but now is the time for you to keep yours! Drive carefully until you find a safe place to pull over.
DON’T open the hood immediately. It’s hot in there, and you risk being burned if you act too soon. Wait until the gauge moves back to the normal range or the light extinguishes before you open the hood.
DON’T wait for it to get better on its own. An overheating engine won’t repair itself, and you should bring your car in to Jiffy Lube as soon as you can.

You might be interested: Why Is Mercedes G Wagon So Expensive?

Now that you know what actions to take (or not take!) when your car overheats, let’s look for ways to help prevent the problem in the first place. Your engine’s cooling system, controlled by the car thermostat, keeps coolant circulating through the engine and radiator.
View full answer

Is it OK to drive car after it overheats?

If your car is overheating, you should definitely not drive it. This could be due to several factors, including low coolant levels or a faulty cooling system. Driving an overheated car puts additional strain on the engine, leading to further damage and costly repairs down the road.
View full answer

How long does it take for an engine to cool down completely?

Under normal circumstances, it takes a minimum of 30 minutes for an overheated engine to cool down to a temperature where it is safe to inspect it and potentially work on it.
View full answer

How long does it take a car engine to cool down?

How Long Does It Take For a Car to Cool Down Completely? Have you ever wondered how long it takes for your car to cool down after using it? Once you turn your car engine off, it still takes some time for your engine to cool down completely. Usually, it takes around 30 minutes for your car’s engine to cool enough where it is and check engine components.
View full answer

How much does it cost to fix an overheating BMW?

How much does it cost to fix an overheating car? Every time I start driving, I notice my car’s thermometer hits the H. I may have even seen smoke the other day. I think my car is overheating, but I’m nervous about the cost of repairs. How much will it cost to fix an overheating car? An overheating car is never good and requires attention ASAP, so you’ll want to head to a mechanic as soon as you can.

Broken thermostatLeaking heating hoseLack of antifreeze or coolantBroken cooling fan Broken water pumpBroken Broken head gasket

The least expensive repairs will be replacing a thermostat, heating hose, or refilling your antifreeze or coolant. However, if you have a broken water pump, radiator, or head gasket, your repairs will cost more as these are essential in keeping your engine cool.

While the cost of repairs can seem overwhelming, the sooner you get the overheating fixed, the less your repairs will likely cost.
It’d be less expensive to fix a leaking radiator than a completely broken one or an engine that’s overheated to the point of being unsalvageable.
If you’re looking for ways to save money towards the cost of your repairs, use the app.

Once you download Jerry, answer a handful of questions that will take you roughly 45 seconds to complete and you’ll immediately get car insurance quotes for coverage similar to your current plan. Jerry customers save an average of $887 a year, WHY YOU CAN TRUST JERRY Jerry partners with more than 50 insurance companies, but our content is independently researched, written, and fact-checked by our team of editors and agents.
View full answer

How do I know if my engine is damaged from overheating?

If your engine has experienced damage from overheating, you may notice symptoms like burning scents, fluid leaks, or (in a worst-case scenario) a cracked engine block. If you suspect your engine may be damaged due to overheating, it’s best to have it assessed by a mechanic.

Naturally, a car’s engine heats up the longer it runs.
Your engine coolant system is designed to kick in and help regulate your engine’s temperature to protect it from the serious damage that can come with overheating—so you can continue on your trip safely and uninterrupted.
However, problems may still arise and go unnoticed, and when that happens, an overheated engine can result in serious damage.

Here to show you some of the symptoms you should watch out for is Jerry, the trustworthy super app that makes finding the best car insurance policy a breeze. Compare insurance quotes from 50+ carriers with Jerry in under 45 seconds
View full answer

What is the fastest way to cool an engine down?

It’s better to pull over and deal with it right away instead of risking very expensive repairs later.
There are a number of things that can cause your engine to overheat.
Some of these are fairly common issues, especially on a hot summer day in the Phoenix, Tempe and Chandler areas.
Improperly Circulating Coolant If the water/antifreeze mixture isn’t circulating correctly, the engine will start to overheat.

There’s A Leak If your water/antifreeze levels are constantly low, there’s a leak in your cooling system somewhere,
If you’re experiencing this, make an appointment with us today.
We’ll track down the leak and give you an affordable estimate for the repair.
A Hose Needs Replacing Over time, the hoses that circulate your coolant may become blocked or detached.

How does a BMW cooling system work?

BMW Cooling Systems Internal combustion engines rely on a cooling system to regulate the engine temperature as well as provide heat for the climate control system (HVAC) and the mechanics of it hasn’t changed in 120-odd years. BMW systems are not much different than any other car but we created this page to educate all BMW owners on how the system works and address specific problem areas unique to BMWs that any owner should be aware of.Over time, cooling systems have become more sophisticated and complex but the core components haven’t really changed:

Cooling/heat-absorbing fluid composed of mono-ethylene glycol, combined with distilled water. Water Pump to circulate the coolant mix through the engine block, sub-components, and maintain pressure. Some systems use a smaller secondary pump to deliver coolant to other systems. Thermostat to control the coolant temp. Radiator that uses airflow to lower the coolant temperature. Heat management systems to prevent overheating (aka a radiator fan). Expansion overflow tank that helps regulate the coolant level throughout the system. Hoses that carry coolant from one component to another.

In essence, the cooling system uses a robust anti-boil/anti-freeze chemical mix that absorbs heat in the engine, circulates the heated fluid to the radiator for cooling, and then runs the cooled fluid back through the engine. Additional sub-systems like the heater core, turbochargers, and oil coolers are tied in with the main engine cooling system or have their own dedicated sub-systems.

BMW Cooling System Fundamentals The engine, hoses, radiator, and expansion tank are filled with coolant mixture. On a BMW this is a mix of monoethylene glycol and distilled water. The water pump circulates the coolant and keeps the system pressurized. Starting from the pump, coolant enters the engine block and cylinder head to regulate internal temperatures.

When hot coolant leaves the engine block it is split into two directions: to the thermostat or to the heater core to heat your interior. Flow through the radiator is controlled by the thermostat. Depending on coolant temp, the thermostat will be either closed or partially open.

When closed coolant flow through the radiator is stopped and hot coolant will flow from the engine block to the thermostat and back through the water pump where it will re-enter the engine. When the thermostat is open, radiator flow resumes and cooled coolant enters the thermostat, mixes with the hot coolant, and then continues onto the water pump.

Once the coolant temp is lowered the thermostat closes again. The expansion tank holds overflow and extra fluid to be used to supplement fluid being used elsewhere, such as for the heater core or for an oil cooler.Older models have two phases of operation: warm-up and regular.

During the warm-up phase the thermostat is closed, which allows coolant to circulate through the engine again and bring the engine up to operating temp sooner. Once in regular mode the thermostat will open partially to regulate coolant temp. More modern BMWs have a plethora of operating modes to meet various cooling goals.

They use sophisticated electronics to control the operation of the thermostat and water pump to oversee internal engine and accessory temps.On modern BMWs there are multiple cooling “circuits” dedicated to specific components. In addition to the traditional engine circuit there are now separate systems for the turbocharger(s), charge air intake manifold, transmission oil, and the HVAC.

Each of these may have its own cooling circuit with a dedicated water pump, hoses, and even its own radiator.
In some cases the system is totally self-contained while others may mix with another system.
For example, the B46 330i/430i/530i turbo and HVAC systems are mixed while the intake charged air cooler is completely separate.

You might be interested: How Long Is A Ford Ranger?

Looking at the mess of hoses under the hood you may be looking at more than one cooling system.Few vehicle systems will leave you stranded on the side of the road but the cooling system is certainly near the top of the list. Regular and preventative maintenance is crucial.

Cooling systems break down and fail when regular service is ignored, regardless of the materials or quality of components. There is almost always a tell-tale sign of impending cooling system failure so do yourself a favor and address any warning signs ASAP.This page is laid out by component rather than by car because the same principles apply regardless of year or generation.

We have identified any problem areas below as well. BMW Coolant BMW prefers a specific coolant blend for all of their cars that is compatible with the extensive use of aluminum, magnesium, and plastic found in BMW engines. Since BMW calls for a specific formula (G48 or HT12, see below) there are very few alternative brands on the market.

Buying an off-the-shelf coolant from an auto parts store will likely be incorrect for your BMW unless the label specifically says it’s BMW compatible. Don’t go by just the color alone! In addition to the Genuine BMW we also offer Red Line, Rowe Hightec, and Fuchs Maintain Fricofin. The Genuine is the most popular even though some others offer a higher boiling point than Original BMW.

BMW coolant has traditionally been light blue in color (G48 formula). In 2018 BMW announced a new coolant formula that is green in color (HT12). The new BMW HT12 green coolant is backwards compatible with older models and the two can be mixed. It has many of the same properties and boiling points but includes a silicate additive that coats metal surfaces to prevent contamination.

However, the silicate coating breaks down over time so the new green coolant must be replaced every two years,
The blue coolant used other coating additives that lasted longer but are not environmentally-friendly.
BMW recommends the coolant be mixed with distilled water.
Why do they insist on distilled water? The water goes through multimedia particulate and charcoal filters and is then distilled.

The water is vaporized into pure water and then bottled. All other minerals are left behind. This avoids any contamination that might occur with the additives and chemicals from regular tap water. BMW recommends a mix of 50:50 but this can vary depending on temperature requirements.

Note that many racing organizations do not allow coolant at all because spills or leaks on the track are difficult and time consuming to clean up and large coolant spills are slippery.Coolant also has the job of lubricating the water pump.
If you feel coolant between your fingers it has a lubricity to it.

This gives the moving parts of the water pump some lubrication that straight water will not.Red Line Water Wetter is a non-glycol lubricant and corrosion inhibitor that is allowed in most racing series. It can be mixed with distilled water to give better lubrication or used in conjunction with coolant.

BMW Water Pump The water pump is centrally located in the engine and is either mechanical or electric, depending on the generation. Nearly all BMWs from 2006-2018 use an electric pump. Previous to 2006 and many post-2018 are belt-driven pumps. More on this in a minute.The pump works like a water mill – the blades of the pump (impeller) scoop up coolant and push it through the system.

Most pumps are located at the front center of the engine with direct access to the engine block and cylinder head. A hose connects it to the thermostat. Mechanical pumps are working all the time while electrical pumps were programmed to work only when needed, determined by logic built in to the engine computer.

Overall, BMW water pumps have been quite reliable with a few infamous exceptions: 1992-1995 M50 6-cylinder, This mechanical pump used plastic for its spinning impeller for the first time. The plastic blades would break apart, leaving nothing to scoop up the coolant.

The failure happened without warning and left quite a few people stranded. BMW moved quickly by reverting to a metal impeller pump while they figured out the plastics issue. By 1998 they had re-released the pump with a composite impeller that has been ultra-reliable ever since. Some people prefer the reassurance of a metal impeller and the aftermarket continues to offer it (but unnecessary as far as we’re concerned).

A is also available with more flow and stainless steel materials.2006-2013 N52/N54 6-cylinder, This was BMW’s first electric water pump. Switching to electric offered many advantages – less wear and tear on belts, simplified the belt and pulley system, better fuel economy due to less parasitic drag, and cooling could come under electronic control.

The pump is mounted on the side of the engine block. The problem with this electric design is that the internal electrical components fail without any warning. Ironically, one compelling theory is they fail due to heat! There is no fix other than total replacement of the pump. If someone could come up with an improved circuit board or make it serviceable they would make a small fortune.

It’s this unresolved failure that ruined an otherwise innovative design upgrade. If your electric water pump has more than 60,000 miles you’re on borrowed time and a failure could happen at any moment. The sudden failures of electric water pumps, with no clear explanation, and lack of a long-term permanent resolution seems to have led BMW to abandon electric pumps for some 2019-on new models. The latest G20 3-series and B58TU engine have reverted to a mechanical water pump paired with a Heat Management Module with extensive cooling responsibilities.

BMW Thermostat The thermostat regulates the temperature of the coolant – allowing hot coolant to circulate or mixing in some cooled coolant to lower the overall temperature, depending on need. When the engine is cold, or you turn your heater on, the thermostat will be closed, forcing the coolant to circulate back through the hot engine.

When the coolant gets to a certain hot temperature the thermostat will open and coolant from the radiator is allowed to enter the system. Keeping the thermostat closed will help the engine heat up faster (reducing emissions or improving performance) while having a open thermostat will lead to engine temperatures being too low.Older thermostats were unbelievable simple: a spring-loaded diaphragm sealed against a metal ring with wax.

As temps and pressures rise the diaphragm will open against the wax seal and coolant would flow. Later thermostats are electrically controlled to better manage engine temp. Don’t think of the thermostat as one single door, either open or closed. It’s more like cars merging on a highway.

BMW Radiator The radiator (and its shell) used to be the most recognizable styling feature on a car because it sat front and center to maximize surface area to air flow. Even though the radiator is now tucked within the bodywork and all but invisible its principles of operation remain unchanged.

Even though there is some “radiant” heat the radiator uses convection cooling – hot coolant comes in one end, is passed through tiny tubes in the core that are exposed to air flow, and cooled fluid exits out the other end. On later models (2006+) the car can have multiple radiators supporting different systems and cooling demands.

For example, the transmission oil may be cooled by a dedicated radiator. Most BMW radiators use an aluminum core with tiny tubes for coolant flow. Aluminum strips, also known as fins, are then woven between each tube to direct air flow. All factory BMW radiators are known as single-pass designs – the fluid moves from one side to the other.

More advanced designs use a double or even where coolant criss-crosses the core for longer exposure to cooling air.
Radiator cores themselves are quite robust and rarely the source of cooling problems unless damaged by debris or wear and tear after high mileage.
For track and race cars we advise cleaning the debris and klag from the radiator(s) to help improve air flow.

It’s standard practice in our race shop to clear radiators at least between races – or sometimes more frequently – and we generally see a modest temperature improvement with each cleaning. BMW radiator problems usually stem from the plastic used for the end tanks and hose connections. Over time and with exposure these tanks will develop cracks and leaks. It may take several years but it’s only a matter of time before this plastic fails. Depending on your needs you can replace it with another OEM-type plastic design or upgrade to an all-aluminum design.

Note that OEM radiators will perform just like the original and with the same expectations of performance and longevity. High priced aluminum radiators are typically better and go through extensive testing and quality control. However, cheap aluminum may be inferior and leave you with more regrets than benefits.

When it comes to aftermarket parts, you get what you pay for.It’s important to note the differences between a radiator and a heat exchanger. They both have similar jobs and sometimes are interchanged in conversation. The radiator uses convection cooling by air flow to cool the fluid mixture (water:air).

The heat exchanger uses fluid to cool something else (usually intake air or oil) and is dependent on a radiator to supply the cooling fluid.
There are two common applications of heat exchangers in BMWs: oil cooling and intake air cooling.
BMW will often use the term heat exchanger when they really mean radiator.

It seems that they want to differentiate the engine cooling radiator from a radiator used for another system (intake air or oil cooling).Oil heat exchangers have taken the place of traditional oil:air coolers and are used for engine or transmission oil cooling on a number of models. The 2017+ B46 4-cylinder and B58 6-cylinder engines have a heat exchanger integrated inside the intake manifold. Instead of there being an open cavity and plenums inside the manifold, there’s a small water:air cooler. This is the ideal place to cool the incoming air before it enters the cylinder head.

You might be interested: How To Unlock A Mercedes Benz Steering Wheel?

Heatsoak Management A radiator is only effective at convective cooling when the car is in motion. This airflow over the tubes is the only way the radiator can cool the fluid. That’s why all street cars have a fan to provide auxiliary air flow. Older cars have the fan mounted on the water pump shaft and the fan spins all the time.

Later cars (around 1999) have a fully electric fan that is triggered by coolant temperature.
Once the coolant reaches a certain temperature the fan turns on.
An extra threshold might be built in to engage a faster speed.
The electric fans are superior especially in heavy traffic where speeds and air flow are low.Intelligent heat management also applies to newer models with electric water pumps and more sophisticated electronics.

The logic built into the engine computer can turn the water pump on or off, depending on the need. Engine temperature is directly related to vehicle efficiency so it may be advantageous to have the engine run hotter than “normal”. In that case it doesn’t make sense to have a water pump that is engaged all the time.

Conversely, the electric pump can also be used to cool and circulate fluid after the engine has turned off. This is especially critical on turbochargers and the BMW systems will circulate coolant through them after shut down. There are also smaller auxiliary water pumps on some models that do the same thing for various systems.

BMW Expansion Tank The expansion tank is also known as the overflow tank or coolant reservoir. As cooling demands change the level of coolant in this tank will go up or down. It’s also a place where coolant can spill into when system pressure is too high.

The cap on the tank serves a vital purpose of venting/controlling system pressure. Too much pressure needs to be vented to prevent a failure. Too little pressure leads to poor system performance. For this reason the expansion tank, cap, and bleed valve are the highest points of the cooling system.The expansion tank on 1992+ models seems to be the most common source of leaks and broken plastic.

It must be a material issue or quality control problem that allows the plastic to split or warp and cause leaks. Failures are not an epidemic and they typically last 5-6 years so maybe that’s just their expected demise. Unless the car is tracked or raced, most people simply reinstall an OEM plastic tank with the expectation that it will fail and need replacement again in the future.

BMW Cooling Hoses Hoses and connections have evolved from slip fit with a hose clamp to positive-locking types with solid fittings. It used to be common to replace hoses because of a leak or deformed hose. But now the fittings and tolerances between hard parts is so close that leaks are rare.

BMW Split Cooling System Starting in 2016-2017 BMW implemented a split cooling strategy to their new engines. Split cooling separates the engine block and the cylinder head(s) to control their temperatures independently. The cylinder head and turbo(s) receives a constant supply of coolant but cooling to the engine block can be reduced or turned off.

During a cold-start, warm-up, or normal driving coolant circulates through the cylinder head and turbo but is cut off from the engine block.
By re-directing more hot coolant to the head, the engine will warm up faster and reduce cold-start emissions.
The system first appeared on the 2016-2017 N63TU2 V8 and was controlled through a valve in the water pump.

Separate cooling circuits of varying sizes were run through the engine block. The system was overhauled and became more sophisticated with the B46D/B58D engines for 2019. This version uses an external heat management module with a split cooling valve that controls coolant distribution.

Additional Cooling Demands Cars are not getting any simpler and its the cooling systems that have had to do more with less.
Cars have become more aerodynamic, taking frontal area away from the radiator space.
More parts and systems are jammed under the hood which traps heat.
Turbochargers generate more heat under the hood too and also require their own cooling and oiling systems.

Oil coolers are either air- or water-cooled. Even electronics get their own cooling fans. Below we will briefly detail the various sub-systems that require or receive cooling resources. Transmission Oil, Nearly all BMW automatic transmissions, and some manuals, get their oil cooled with the help of the engine coolant mix.

In most cases there is a heat exchanger that circulates cool fluid around a chamber of transmission oil. The oil is carried to and returned from the heat exchanger by rubber hoses. Coolant is also carried by a different set of hoses, usually from the radiator. Engine Oil, Most M models and some factory performance options include an engine oil cooler.

In older models it’s a simple radiator design using oil:air convection. But in other models coolant is used with a heat exchanger, similar to the transmission oil system above. Turbochargers, The first great wave of factory BMW turbo models appeared in 2007 with the N54 135i/335i/535i.

By using exhaust gases (which are already super hot), and then compressing intake air (which turns it hot), a cooling solution is needed on each turbo. BMW turbos get their oil and coolant supply from the engine block through dedicated lines. Cooling demands are managed by the engine computer which will continue pumping coolant through the block and turbos even if the engine is off.

M Sport, Increased Top Speed, or Load Increase, You can’t say BMW doesn’t take performance seriously. If your car comes with the right combination of options you got one or two additional radiators and an auxiliary water pump, just for additional cooling performance.

F3X 228i/328i/428i N20 Cooling System Base Sport Line

With a few exceptions BMW cooling systems are reliable and up to the task of providing adequate cooling for daily driving. Upgrades exist, mostly to get away from the problematic plastic pieces. Making the cooling system more robust and bulletproof does no harm even if it may be excessive for daily street use.

However, aluminum expansion tanks and radiators exist for a reason and that’s to address the shortcomings of the original design. In the end your only regret is that you spent too much.For BimmerWorld, better cooling became a necessity on our F30 328i race cars built for endurance racing in the IMSA Continental Sports Car Challenge.

We found that even with the stock turbo it was sustained high temperatures that killed our performance. We petitioned for a bigger turbo on the grounds that the larger turbo was less-stressed and could put out the same power with lower temps but were denied.

That required us to really attack the cooling system on the F30 to make it more efficient for hours of continuous racing.While building our cooling catalog we came across the interesting, and confusing, cooling system design of the 2012-2019 N20 engine.
This was used in F22 228i, F30 320i/328i, and F32 428i models.

The various trim and package options for these cars meant different equipment was used. From racing the N20 engine we already know of the cooling struggle with this platform. Below you will find our notes on the different factory options and how they relate to cooling logic.

Please realize these are only notes and open to interpretation and changes as we encounter new info.Base Model, Manual Transmission – as basic (simple) as it gets.1 radiator, upper and lower hoses, electric water pump, and thermostat.Base Model, Auto Transmission – same as the manual but adds a transmission oil heat exchanger which alters the hose layout somewhat.

The transmission cooling takes cool coolant from the water pump hose, runs through the heat exchanger, and exits to a radiator. The main 3-point hose for this circuit looks complicated because it also supplies coolant to the heater core.Sport Line, Manual Transmission – Sport Line (code ZSP) added a second small radiator in the passenger side that added cooling capacity and surface area.

The routing of the hoses seems to indicate this benefited the turbo cooling the most. What seems odd to us is the upper radiator hose which would be hot coolant entering the radiator. However, there is a line extending to the small radiator outlet port. So we’re not sure if this is hot coolant dumping into cool coolant or cool coolant making its way up a line to mix with hot coolant.

Either way it seems this was done to close off the small port on the radiator (left un-used with the aux radiator).Sport Line, Auto Transmission – same as the manual but adds a transmission oil heat exchanger which alters the hose layout somewhat. Auto transmission coolant passes through the main radiator.High Speed Synchronization (code 840) – this was a higher top speed matched to summer performance tires.

It seems that you can only get High Speed Sync with the Sport Line. But if you ordered all-season tires or 17″ wheels the High Speed Sync was taken away. There is no cooling difference compared to Sport Line so this just confuses parts diagrams. M Sport M Sport, Manual Transmission – M Sport (code P337) was a large trim package that also added a second auxiliary radiator on the driver side.

So now the car has one large main radiator and two small radiators. There is a crossover hose connecting the two aux radiators. The upper radiator hose also has a smaller line that feeds into the radiator that was previously used for auto transmission radiator.

That now becomes additional cooling capacity and surface area for engine cooling.
The passenger aux cooler seems focused on turbo cooling (as in the Sport Line).
The driver aux cooler seems dedicated to auto transmission cooling.M Sport, Auto Transmission – same as the manual but adds a transmission oil heat exchanger which alters the hose layout somewhat.

Auto transmission coolant passes through the driver aux radiator.BMW 17127609532 vs 17127596839 hose differences. This is the lower coolant hose for automatic transmission models. Base models use the 532 number. Sport and M Sport models use the 839 number.

We have inspected these side by side and found no difference between them.
They both have 3 connection points (water pump, AT heat exchanger, and heater core) and follow the same layout and even the bends in the hoses are the same or extremely close.
Our best guess is that Sport and M Sport cooling components were assembled as a module and BMW needed to separate their inventory for each (that’s only a guess though).

BMW Cooling System Diagrams BMW Cooling Products : BMW Cooling Systems
View full answer

Aisyah bin Tijah