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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How to bleed a water pump that is mechanical (older BMWs)
Tools Required:
- Jack (depending on model)
- Jack postures (depending on model)
- the screwdriver
- Auto Key
How can you tell if your water pump is mechanical? A mechanical water pump is almost probably present in a BMW that was built before 2004. With the E90 in 2004, BMW started adding electric water pumps on the 3 Series. The E46, E36, and E30 are belt-driven mechanical water pumps, as are all prior 3 Series models.
These older BMW models require manual bleeding. Even while it’s a fairly quick and simple process, it does require more patience and time than versions of electric water pumps that “self-bleed.” These automobiles have mechanical water pumps, thermostats, and reservoirs positioned on the radiator’s side.
**To lift the front end of these vehicles, I utilize a jack, jack stands, or ramps. Why? Because the bleed screw and radiator are now the highest points on the coolant system, this will let the air move more easily. The majority of people don’t do it, but in my experience, it’s the best approach to guarantee that all air bubbles are eliminated from the cooling system.
**This bleed method will still function flawlessly if your heater is broken. I’ve done this procedure a lot of times when someone’s a/c control module has failed. Simply omit the step requiring you to turn on the heat.
- Put the front end on ramps or jack it up. (This step is advised but not necessary.)
- Open the bleed screw, then add coolant until it reaches the fill line. Take off the fill cap.
- Set the fan speed and the heat to their highest settings.
- The engine should be started and given time to reach working temperature. Release air when it heats up by loosening the bleed screw, then tighten it again.
- Reinstall the fill cap and tighten it firmly. Press the gas pedal to increase the engine’s rotational speed to 2000–2500 RPMs. If your heat works, it should be pumping hot air at this stage at full force. You can see from this that the heater core is dripping with coolant.
- After tightening the bleed screw, setting the car down and giving it a short spin, you’re done!
What is the time required to bleed coolant on a BMW?
Depending on the model and approach you use, it typically takes 15 to 30 minutes. However, heating the engine and draining the coolant both take about 15-20 minutes.
Between the overflow tank and thermostat, your cooling system can leak a little. However, you must fill the coolant and drive the vehicle with the radiator cover off in order to fully bleed.
The water needs to be turned on and adjusted to run slowly. To remove the radiator from the cooling system, turn off your car.
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.
Do you have to bleed before adding coolant each time?
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.
What occurs if coolant is not bled?
Air can accumulate inside your radiators over time, causing cold patches and less-than-ideal performance from your home heating systems.
Radiators should be bled regularly because otherwise, the problem will get worse. It might eventually prevent your central heating from achieving your ideal temperature, even when it is turned up to its highest setting.
To assist ensure that your home heating remains in top condition and continues to operate at its peak efficiency, go to our information on How To Bleed A Radiator.
Does bleeding my coolant before adding more make sense?
Bleeding the coolant system will remove air pockets that can form while adding new coolant if you recently drained coolant or antifreeze or need to replace it because it’s below typical levels. The cooling system may not function properly due to air pockets, which may result in other regions of your car being less heated. To prevent air pockets from accumulating and maintain the coolant system’s peak performance, this page describes how to correctly bleed the coolant system.
How much time does a radiator need to bleed?
What is the time required to bleed a radiator? Bleeding a radiator usually takes approximately 20 to 30 seconds. Depending on the size of the radiator and how much air needs to be bled, this could go up to a minute.
Without a key, how do you bleed a radiator?
A standard screwdriver is the best substitute for a bleed key when working with radiators that have a slotted bleed screw. To bleed the radiator, just place the screwdriver into the slot and turn it counterclockwise.
There are various available solutions if your radiator has a different type of bleed screw, possibly one with a square or hexagonal aperture.
To hold and turn the nut for a successful radiator bleed, use an Allen key, spanners, or pliers.
See our Advice Centre article on How to Bleed a Radiator for further information on the fundamentals of the procedure.
Why is my BMW 328i from 2007 overheating?
The radiator fan, a broken thermostat, or a coolant leak (from the water pump, radiator, hose, etc.) are the three most frequent causes of overheating in a BMW 328i. fluid leak (water pump, radiator, hose etc.)
How hot should a BMW run?
The majority of experts concur that your engine should operate between 195 and 220 degrees. Your needle should always retain a position directly in the centre of your gauge.
How can I tell whether my coolant is flowing properly?
- Make sure the engine and radiator are cool, then park your car on a flat surface.
- Find the thermostat by lifting the hood of your car. You can do this by moving towards the engine while following the upper radiator hose. The thermostat housing will be connected to the other end of this hose. Your thermostat should be located in the housing in the majority of autos. On some cars, the lower radiator hose will be connected to the thermostat housing. Consult your vehicle’s service manual for more information if you need help locating your thermostat.
- You must then test your car’s thermostat. To check the coolant flow, you can remove the radiator cap from your car. Start the engine of your car and let it idle. To check if the coolant flows, look through the radiator filler neck. It shouldn’t be flowing at this point because your automobile hasn’t achieved the required operating temperature to open the thermostat.
- If you observe coolant flowing, the thermostat valve is likely open. This is typically a good sign that your car’s thermostat needs to be replaced.
- If the coolant does not appear to be flowing, wait until the engine of your automobile has warmed to operating temperature. Examine the radiator filler neck once more to check if the coolant is flowing. When the temperature gauge on your automobile begins to increase but the coolant is still not flowing, this indicates that the thermostat is closed.