How To Bleed BMW 325I Cooling System?

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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 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.

How can a cooling system be used to bleed a bleeder valve?

You should now switch the climate control heat to MAX after starting your vehicle. Depending on the vehicle, many cars include a valve that, if the temperature control is set to cold, prevents coolant from flowing within the thermal pack. This method will have no effect on other autos because they divert the airflow rather than the coolant flow. No matter what model you have, turning up your temperature control to the MAX heat is a simple process.

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.

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.

How is a water pump bled?

  • First, shut off the electricity.
  • Step two: Prevent water damage.
  • Step 3: Close the shut-off and gat valve to stop the flow of water.
  • 4th Step: Carefully unfasten the pump bleed screw.
  • Step 5: Clean up every drop of water that spills out of the pump.
  • Sixth step: Reinstall the bleed screw.
  • Step 7: Start the generator.

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.

What causes BMW water pumps to fail?

The age and intensive use of BMW vehicles are the most frequent causes of water pump failure. Most car parts eventually start to malfunction due to frequent use and abuse. The water pump will gradually deteriorate throughout the course of your vehicle’s lifetime because it is constructed of plastic.

Around the 80,000-mile mark, it is advised that you get your BMW’s water pump inspected and replaced in order to prevent more expensive repairs down the road.

What symptoms indicate a faulty water pump in a BMW?

Another significant factor in the equation is age and distance. Despite any other issues, you might want to think about installing a new water pump if your automobile has logged tens of thousands of kilometers. Water pumps do not last indefinitely, so if yours has served you well for 75,000 miles with no issues at all, it may be time to think about replacing it so you don’t end up on the side of the road when your water pump decides it has outlived its usefulness.

How can you tell whether your cooling system is running on air?

One of the many indications that there are air pockets in the coolant system is a broken car heater. There won’t be any heat coming from the vents when you turn on the car heater. The air could not be forced out because of the air bubbles. Hot fluid cannot enter the heater core because of the trapped air.

Why is my coolant bubbling even though it’s not hot?

The combustion process is kept closed off by the head gasket. Compressed air will start to leak into the cooling system once it starts to fail at this. Eventually, the air will reach the radiator and cause the coolant to bubble.

The continual discharge of gas from the leaky air and combustion gases will give the coolant the appearance of boiling.

You can check for this symptom by having someone press the accelerator pedal while you watch the coolant bubble. A leaking head gasket is the cause if the coolant rushes up into the container.

To avoid further damage, have the head gasket replaced right away by a qualified mechanic.

How long does it take a radiator to burp?

It takes time and persistence to burp an automobile cooling system. Burping might take up to an hour, depending on the volume of air in the cooling system and the make and model of your car.

However, it takes the engine 5 to 10 minutes to reach the normal operating temperature. The thermostat will turn on at this point to allow coolant to reach the engine.

How can I remove air from the heater core?

This technique can be compared to how we put a child to sleep after hearing it burp. Take your car for a mountain drive if you reside in San Francisco or a nearby mountainous area. On a slope, park it in an inclination. If you don’t have access to this equipment, jack up your automobile so that the front end is higher than the trunk. As you do the following:

  • Prepare your coolant container by getting it.
  • Slowly remove the radiator cap and drain some coolant to prevent bubbles.
  • The heater valve automatically permits the coolant to flow through the heater core once it reaches operational temperature. The air bubble is forced outward by this motion.
  • In this situation, let the automobile sit for 15 to 30 minutes.
  • Keep an eye on the radiator’s coolant level. Occasionally, you will be able to observe the coolant bubbling and burping. Once you notice that the bubbling action has stopped, begin adding the coolant gradually.
  • You ought to witness a constant flow of coolant without any bubbles or burps after around 20 minutes.