You should always bleed the cooling system after draining it or opening it somewhere other than the expansion tank. By bleeding the system, you can make sure there are no air pockets and the coolant can function as it should. It’s an electric pump, thus the bleeding procedure requires a powerful battery. We finished the procedure without a battery charger, despite the BMW repair manual’s recommendation.
The self-bleeding technique should be started by:
The bleeding can then be started by depressing the accelerator pedal for roughly 10 seconds. When you hear the coolant within the engine and radiator moving, you’ll know the procedure has started. Once it has begun, let the car alone for 8 to 10 minutes. After that, the procedure will be finished, and your cooling system will be totally bled and ready for use.
Authored by:
owner of a 1973 Porsche 914 and a 1998 Impreza 2.5RS with a flat-six engine swap. only when opposing perspectives are horizontal.
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Do you seal the coolant tank’s cap or cover throughout the bleeding process, or do you leave it open? If it is closed, is it tightly closed and aligned with the arrows?
As the coolant level drops, I keep the cap open and continue to fill it with coolant. Since the previous plastic bleed screw broke and caused problems, I don’t worry with it anymore.
My preference is to start the pump (use the floor method for electric pumps or start the engine for mechanically driven pumps) while leaving the expansion tank cap off for five minutes and having a jug of coolant ready to pour in, as the level will quickly drop once the pump is running, even if the tank is brimmed.
On these tanks, the system self-bleeds, thus removing the bleed screw isn’t actually necessary, but I still do it to quickly release any trapped air.
When fixing a cooling system, it’s best practice to order bleed screws, stopcocks, and any typical fragile hoses.
You may like it, however the N52/54-55 with the electric pump should not be serviced in this manner. The bleed screw, which is located on the reservoir where the air is pushed out of the head back into the reservoir, allows air to exit the reservoir while the coolant fills it and from the system when air is pushed back into the reservoir from the system.
According to BMW’s published instructions, you should fill the reservoir up until coolant begins to leak out of the bleed screw, then completely tighten the screw and reservoir lid before starting the water pump.
This past weekend, I performed a coolant flush on my 2013 328i E92 Coupe, and everything went without a hitch until the bleeding procedure (expansion tank cap on and bleeder valve closed). I turned on the ignition, pressed the start button until the dashboard lit up, set the heat to 84 degrees, turned the fan to low, then depressed the gas pedal for 10 seconds to initiate the bleeding process (heard the water pump engage). The procedure came to an end and the dashboard lit up after around ten seconds. I tried other combinations, but got the same outcome (kept turning off). I was very frustrated till I found the solution (keep it from shutting off). Set the headlights to low beams, wait the whole 12 minutes, and the process is over. Just in case someone else was experiencing the same thing, I thought I’d share this.
Just last weekend, I observed my BMW technician performing this in my car. He started the bleed procedure, ran it twice, and left the coolant tank lid off the entire time after replacing my coolant expansion tank and installing a new radiator.
What occurs if BMW fails to bleed the coolant?
My 2014 335i gt’s radiator vent line broke, leaking some coolant, therefore I had to follow the instructions for bleeding the system after adding the coolant back in.
If anyone knows why they don’t just instruct you to put the engine on and drive about to let the air out, please let me know.
I have some ideas, but I’m curious if someone here who is “in the know” could clarify this.
You can’t fully fill the system with coolant if the air hasn’t been bled out. The hoses will contain air entrapment areas. If the engine and transmission are operated, they may overheat and destroy a variety of parts, beginning with the water pump and becoming worse from there.
No, the purpose is to remove air from the system. Since the system is sealed, any trapped air will remain there unless it is purged. For this reason, the coolant must also be injected under pressure into the circuit. This Oldsmobile is not your father’s.
Oh, I understood what bleeding was and why it was necessary. I apologize if I was unclear.
My concern related to how BMW decided to handle it. My friend and I are discussing how you bleed the system on a BMW as opposed to another kind of automobile. He believes that BMW’s process is overly complex. Procedures like these don’t exist simply because they do, thus I believe there is a strong rationale for it.
So here’s my inquiry: what design issue was BMW attempting to address by developing a method for bleeding the coolant circuit while the engine is not running?
I don’t necessarily see a design issue. If you wait for the engine to reach operating temperature before the cooling system can purge trapped air, damage may occur before the air exits the system since coolant doesn’t circulate through the system completely until then. That cannot occur if the air is purged without starting the engine.
He is referring to a thermostat; once the coolant reaches the desired temperature, the thermostat opens, and the coolant circulates throughout the entire system.
Don’t forget to fully activate your heater so that the water can also pass through the heater core.
No car, not even an Oldsmobile or a Honda, can be bled by just driving it around; instead, a bleeder screw is located at the highest point of the cooling system, or the overflow/radiator cap is used.
What is the time required to bleed coolant on a BMW?
FAQs. How much time does it take to bleed the cooling system of air? Depending on the model and approach you use, it typically takes 15 to 30 minutes. However, warming the engine and removing the coolant takes about 15 to 20 minutes.
Do you need to bleed the cooling system of air?
Your vehicle’s cooling system needs to be bled of air. Hot areas or air pockets can be hazardous. In addition to the heater producing little or no heat, it might also result in:
- heating of the engine
- Open the engine.
- enclose the engine
- Boost emissions
Hot spots in the system are typically caused by replacing a system component, changing the coolant, or maintaining the cooling system in your car. On some car models, air may occasionally enter the system through the coolant reservoir.
This is especially true for newer car designs where the radiator is positioned lower than the engine.
A hot spot is nothing more than trapped pockets of air or bubbles within the cooling system tubes that prohibit coolant from removing heat from those regions, overheating the engine and triggering the onset of corrosion.
Depending on whether your system has bleeding screws or not, there are three alternative ways to bleed the air out of the cooling system.
If you’re unsure whether your system includes bleeding screws, check your car’s owner’s manual or the service manual for your vehicle. You can get a repair handbook online or at any number of auto parts retailers for your specific vehicle’s make and model. Nevertheless, your neighborhood public library’s reference section might have a copy of the manual.
Please continue reading. You might be able to choose the approach to employ in your specific car with the help of the information supplied below.
Use only the antifreeze that the automaker has advised. Consult the owner’s manual or repair manual for your car. And use only distilled water to combine it.
Which coolant does BMW employ?
No matter what type of car you drive, whether it’s a BMW, Porsche, Mercedes Benz, Audi, Mini, or Volkswagen, your car circulates a solution of water and coolant to dissipate the heat generated within the engine and prevent it from completely melting down (one notable exception are older Porsche models that are air and oil cooled and did not use water or coolant, but instead circulated a large amount of oil to dissipate the heat).
A Spectrum of Colors
Which coolant type is best for your BMW, Porsche, Mercedes Benz, Audi, or Volkswagen out of the many available options? The answer is the kind that was initially installed in your car. Your coolant may be green, pink, blue, yellow, or even clear depending on the manufacturer. All coolants are naturally transparent, and dye is used to give them color. It has no impact on the coolant’s chemical properties that each producer adds their own colour blend. Because the water in Europe is substantially harder than the water in the United States, European manufacturers prefer coolant that is phosphate-free.
Inorganic Acid Technology (IAT), Organic Acid Technology (OAT), and Hybrid Organic Acid Technology (HOAT) are the three most common coolant types available today. A HOAT coolant is used by your BMW, Porsche, Mercedes Benz, Audi, or Volkswagen.
In order to protect aluminum surfaces, silicate is added to OAT coolants to create HOAT coolants. The cylinder heads and radiators, as well as other parts of your BMW, Mercedes Benz, Porsche, Audi, and Volkswagen engine and cooling systems, are constructed of aluminum.
Silicate and phosphate corrosion inhibitors are not used in OAT coolants. These coolants are made to last for 150,000 miles and have a long service life (or 5 years). It should be mentioned, nevertheless, that German Auto Center and the majority of manufacturers advise cleansing or replacing the coolant every two years.
The metal (Iron) components of the engine and cooling system are protected by traditional coolants, which are IAT coolants and use silicate and phosphate corrosion inhibitors. IAT coolants shouldn’t be utilized because the majority of the iron components in your BMW, Mercedes Benz, Porsche, Mini, Audi, and Volkswagen have been replaced with aluminum and other lighter composites.
It’s crucial to keep in mind that modern German performance cars, whether you drive a Porsche, Mercedes Benz, Mini BMW, Volkswagen, or Audi, will last you for many miles and years if you maintain them properly. German Auto Center in Austin is the place to go for German auto repairs. We will be pleased to help you!
If you replace the thermostat, do you need to bleed the coolant?
The cooling system can be difficult to work on, but auto mechanics must make sure the entire repair or replacement is carried out completely. The technician should make sure the cooling system is completely free of air bubbles after replacing a thermostat. The risk of overheating will increase if not.
Refill antifreeze after replacing the thermostat. Start the car while the radiator cap is off. Allow the antifreeze to circulate throughout the engine for five minutes. Immediately after stopping the engine, let it cool. If required, recheck the antifreeze level and top it off.
What signs indicate air in the cooling system?
In a nutshell, it is caused by air bubbles that are present in the cooling system. Even a small amount can result in air pockets, which obstruct the coolant’s ability to circulate properly. Radiator airlock warning signs and symptoms include:
- overheating while driving normally
- heater not working properly
- decreased effectiveness
- rapid coolant loss and radiator leaks
Regular overheating is bad for your engine, and if the issue is not resolved, it may require expensive repairs in the future.