Kühlmittelverlust, Verbindung Brennraum / Kühlkanal? | Posts 16+

According to this, the pressure-less cold cooling system could potentially be quickly pressurized with a few strong gas bursts. If that's the case, then the situation is clear.

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That's a silly question, wouldn't you also expect further pressure build-up even in a functioning system?

If that were the case, the coolant circuit would eventually burst.
Certainly, at around 100°C, a state of equilibrium between water vapor (pressure) and liquid water is established.

However, the air bubbles in the beam are definitely present, unfortunately.

Best regards, Rainer.

Cooling system checked at BMW. No leaks detected.
To avoid having to go to BMW five times for them to check the cooling system, as has been frequently described in the 1erForum, only to then receive the result: "Everything is okay, it holds pressure, please pay 100 euros," I will ask further, more detailed questions.

dieselschrauber wrote:

Quote: That's a silly question, wouldn't you also expect further pressure build-up even in a functioning system? If that were the case, the coolant circuit would eventually burst.

Okay, that's clear. I actually meant that water can evaporate again...

dieselschrauber wrote:

Certainly, somewhere around 100°C, a state of equilibrium forms between water vapor (pressure) and water.

Yes, that's exactly what I meant. But then the pressure won't be strong enough to make the hose tight again, right?

dieselschrauber wrote:

However, the air bubbles in the beam are definitely present, unfortunately.

Even if the engine - as in this case - is only running at idle ? At approximately 3000 RPM, as some users have described in this forum, I cannot detect any/very few interruptions in the stream. However, the water comes out slightly frothy .

Therefore, here are the questions again for the forum:

1. If there is air in the system after a coolant change, does it automatically remove itself through the bleeder hose and go into the expansion tank? Since then, several hundred kilometers have been driven in varying operating conditions.

2. The pressure remains on the hose even after the engine has completely cooled down, so I can't consider that normal, right?

3. Shouldn't BMW first investigate the remaining pressure after the engine cools down, before the system is pressurized again?

4. What is a simple way to determine the actual pressure in the cooling system?

As always, thank you in advance for a lively discussion.

Best regards.

Okay, please provide the German text you would like me to translate.

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1. If air is present in the system after a coolant change, does it automatically escape through the venting hose into the expansion tank? Since then, several hundred kilometers have been driven under varying operating conditions.

Normally, yes. Some BMWs have a venting option on the radiator. This should be used if available.

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2. The fact that the pressure remains on the hose even after the engine has completely cooled down, can I consider that to be abnormal, or?

Ask a housewife if the pressure cooker still has pressure in it after it has cooled down.

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3. Shouldn't BMW first investigate the remaining pressure after the engine cools down, before the system is pressurized again?

How and with what should this be achieved? If the cooling system allows exhaust gases under high pressure to flow in one direction, it doesn't necessarily have to allow "thick" coolant to flow in the opposite direction under a relatively low pressure (which is generated by the pressure difference).

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4. What is a simple way to determine the actual pressure in the cooling system?

T-fitting and pressure gauge.

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Cooling system was checked at BMW. No loss detected.

Vague, as the combustion pressure is significantly higher than the test pressure for the entire cooling system. If combustion pressure enters the cooling circuit (e.g., through a crack that expands due to heat), the safety valve in the reservoir cap opens and releases pressure to a normal level. When the engine is cold, there will then be a lack of coolant.
The only solution is to exchange them.

A lot of Larry for nothing... save yourself the time and nerves. You either have a crack in the ZK (camera module) or a defective ZK, and philosophical musings won't change that.

If the car is driving normally, just keep driving until you have time to get it repaired.
The risk is that the engine could seize up if the condition suddenly worsens, or that the cylinder bores become worn or blocked, and in the worst case, a water hammer could occur.
Therefore, monitor the situation.

Driving to the same car dealership five times, only to be told each time that "everything is okay" while your car is leaking water, is something that's beyond my comprehension. Why would someone do that?
What should be different on the 6th time going?

Fix it and that's it. It won't take any longer than driving around aimlessly five other times.

Best regards, Rainer.

dieselschrauber wrote:

Driving to the same car dealership five times, only to be told each time that "everything is okay" while your car is leaking water, is something that's beyond my comprehension. Why would someone do that? What should be different on the 6th time going there?

I was only fired once.

dieselschrauber wrote:

Fix it and that's it. It won't take any longer than driving around aimlessly five other times.

How do you detect a hairline crack in the engine block? In 100% of the documented cases in the 1erforum, it was the cause. However, the water losses were already more significant in those cases. So, observation is definitely important. However, the later the damage and the higher the mileage, the less goodwill BMW is likely to show.

Best regards,

Okay, please provide the German text you would like me to translate.

Hello,

There are no discernible differences in the effects between a faulty head gasket and a crack in the cylinder head.

Since with VAG vehicles, cracks without affecting functionality in the cylinder head are considered "normal" depending on mileage and driving profile, I suspect the situation will not be much different with BMW.
For example, cracks are very often found in the thin bridge between two valves.
The question is always: How deep does the crack go? Without a thorough examination (e.g., X-ray?), there's no way to know. Even applying pressure is of limited use, as the conditions can change depending on the operating conditions/temperature.

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How can a hairline crack in the block be identified? In 100% of the documented cases in the 1erforum, was it the cause?

If BMW is willing to offer goodwill gestures, they need to know the criteria used to make those decisions. -> Ask about goodwill gestures directly.

Best regards, Rainer.

Hello everyone!

Steffen G wrote:

... Und weiterhin sollte es doch noch diese Sache mit den chem. Provide proof. whether CO2 is dissolved in the cooling water. as proof of whether exhaust gases are actually entering the cooling system. In my opinion, that would still be a worthwhile recommendation. before you disassemble the engine.

...that would also be my next suggestion in the logical error-finding tree .

It's best to have the same BMW workshop perform the test exactly as follows: "Perform a CO test on the coolant reservoir." (No more, no less!)
This can also be done quickly by the apprentice while passing by the parking lot in front of the workshop, after having registered there beforehand, and it's not an "Xh" matter.
Of course, the vehicle should be in a condition where it is likely to exhibit the most pronounced bubbling or where the hoses are most likely to become fully pressurized.
It will definitely be more cost-effective and likely to be successful than re-running the entire system. If the results are positive, you will certainly be reimbursed for your previous expenses, especially if the company acts generously.

Best regards from Munich!

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In any case, it will be cheaper and more likely to be successful than re-running the system.

If a positive result is found here, you will certainly have your previous costs reimbursed - if it goes well. }

For reasons such as potential reimbursement (essentially, providing proof), this could make sense.

Otherwise, based on the findings so far, I consider this to be as pointless as checking the tire pressure on a flat, leaking tire, just to be safe.

Residual pressure in a cold engine isn't just happening randomly. Every sealed engine has zero pressure when it's cold.

Hi Uncle AutoschrauBär!

Autoservice wrote:

... Otherwise, based on the findings so far, I consider this to be as pointless as checking the tire pressure on a flat, leaky tire, just to be safe. ...

But what if your tire dealer (whose correct diagnosis you are essentially dependent on) always puts the tire with no air pressure into a water bath and then firmly insists that no water is getting in and that it is therefore airtight?!

It seems that even BoDu is aware that something is not normal here .
It's now about getting to the desired outcome (regarding warranty claims?) as quickly as possible, without him having to drive many more kilometers, causing even more consequential damage, and ultimately having the warranty claim rejected...
(o. T.: Regarding the specific topic and the manufacturer/production facilities, I was already perfectly taken care of 14 years ago with my K1200RS ).

Best regards from Munich!

Bo Duke wrote:

How do you detect a hairline crack in a concrete block? Bo

.

Hello!

So, I myself have already been able to identify two cracks in the cylinder bore with the naked eye, of course, after proper cleaning and with good lighting.
The cracks were located approximately 5 cm below the head gasket surface, running one vertically and one horizontally, and apparently extended into the coolant channel.
In one case, the corresponding water passage in the head gasket was blocked by a piece of rubber, so I specifically searched in that area.

Furthermore, there is reportedly a liquid used in the mechanical engineering field that is applied to suspected areas. This liquid seeps into cracks and then glows under UV light.
For example, this is how it is done in aircraft turbines.

And finally, a few years ago, I had an old Hyundai.
which was also putting pressure on the cooling system, and in that case, luck played a bigger role.
There was some kind of small spot in the combustion chamber of the cylinder head, and for some reason, my intuition told me to point an air gun at it.

And the location within the cooling water channel was accessible/visible, and soapy water was sprayed there.
bubbles were observed forming.
So, that was a classic casting defect that only became apparent after many years.

Hi Steffen!

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But what if your tire dealer (whose correct(!) diagnosis you are practically dependent on) ...... is closed?!

That is exactly 2 lines above in the post.

It's all pointless. It's exactly as Rainer and Steffen wrote.

Accurate diagnosis ---> disassemble.

Unfortunately, we cannot pray for his recovery.