Forum5er F07 (GT), F10 & F11
  1. Startseite
  2. Forum
  3. Auto
  4. BMW
  5. 5er
  6. 5er F07 (GT), F10 & F11
  7. Coolant system issue

Coolant system issue

BMW 5er F07 GT
Themenstarteram 23. Oktober 2018 um 15:25

Hello there,

I am novice to this Forum. I was reading all over the topics but couldn't find a relevant to my issue.

My hope is that some expert can answer my question:

I have a 2010 F07 535i GT.

My engine code is N55B30A

The current millage is 140 000 km.

The issue is that the coolant fluid is vanishing from the system but there is no sign of leaking.

I need to top up from min to max at least every 100 km in city. If going to highway then after 25 km the BC notice me to stop and top up.

This whole issues started with change of the cooler radiator which had a leak.

Then I had to change 6 months later the water pump at 130 000 km which went down.

Since these changes I still have this issue which is almost a year know.

I was several times in different workshops (including official BMW) where the system was checked for high pressure but we could not find any sign of leaking in the system.

The oil is dark brown as usual. The engine works fine I do not feel any difference.

Where do I need to look, how can I find the leak? Is there any known issue among the F07 users with similar issue?

Please, help!

Is there any method to find out if there is more O2 in the exhaust which indicates that the coolant is disappearing there?

Regards

Pix

Beste Antwort im Thema
Themenstarteram 29. Oktober 2019 um 22:27

Hi everybody,

 

After one year struggle I've solved the issue. I believe it may be helpful to others to learn the outcome. So here it is.

 

The engine head got loose at the 5th cylinder. Three screws lost their strength. Due to this the gas was escaping into the coolant system. After a while the overpressure opened the emergency valve of the coolant system where it escaped together with the coolant.

The funny thing that the escape didn't produced viewable residuals as it drained down over the small drain whole under the coolant cap. Therefore I never could see any signs of it.

 

So I had to dissasamble the whole engine block, fix it and put it back.

During the dissasamble the problematic screws basically come out with the threads. Due to this all 10 screw threads had to be re-done in an alluminium block. Not an easy thing.

I have a suspicion that this engine was already repaired before improperly and the srews were glued which couldn't hold when the wather pump went down and the temperature was a bit higher then normal.

 

The final proof that the engine gas was escaping to the coolant was showed with a very simple but very useful tool. It had a co2 reagent. The color of the reagent became blue if the hot vapour succed into this device contained co2. I recomend this tool to everybody who have similar issue. Actually it was developed for older (30 and more years cars) but I could apply it successfully and got the assurance that indeed I had an engine issue and not a coolant system one.

 

Pix

39 weitere Antworten
Ähnliche Themen
39 Antworten
am 23. Oktober 2018 um 16:08

Maybe it is an issue to EGR cooler system. There is a "technical action" like a product recall, to replace the system. It happens, the cooler of EGR system leakes coolant into the intake system.

Themenstarteram 23. Oktober 2018 um 16:39

Hi Robin,

My car is a petrol version. As far as I know the EGR is valid only for the Diesel cars.

Any other idea?

Pix

..when loosing coolant at that rate You should find anti-freeze residue next to the leak.

In case You own a hot-climate version (code S823A) there is a supplementary radiator hidden in the right front wheel well in line with he main radiator. In case Your car has it, connecting hoses, clamps and the radiator itself should be checked.

There is a special spray available for locating leaks - it forms bubbles where the leaks exists when the system warms up.

I think they did it this way at the shop.

Themenstarteram 23. Oktober 2018 um 17:47

Hi Max,

Where this code should be checked?

So far there are no any residuals in the engine compartment. That's my main problem. It was many times checked by different workshops and nobody could find any.

Also I am not able to see any drops of water below the car so the vaporization must be very quick and must be substantial in case of high speed since I am not able to go more then cca 25km @ 130km/h speed.

If I take off the bottom cover under the engine there is no any sign of drops either.

Pix

Themenstarteram 23. Oktober 2018 um 17:52

By the way the testing was done with a high pressure solution too.

On the coolant reservoir's inlet there was set a pump with gauge. With the pump the pressure was increased to curtain level and we waited 10-15 mins. I've been told that with this pressure the leak should have revealed itself.

Pix

...was there a pressure drop over time, but they were unable to locate the leak or no pressure drop at all?

am 23. Oktober 2018 um 18:06

Use a white paper tissue to cover the end of your exhaust system, when the motor is running. If any coolant liquid is burned by the motor, then the tissue is getting wet from steam.

This can mean the main gasket for cylinder is leaking. Maybe only during high motor temperature.

...here You find Your car's equipment listed after entering the VIN

https://www.etkbmw.com/bmw/DE/vin/decoder/online

Themenstarteram 23. Oktober 2018 um 18:55

Zitat:

@maxmosley schrieb am 23. Oktober 2018 um 19:57:47 Uhr:

...was there a pressure drop over time, but they were unable to locate the leak or no pressure drop at all?

No pressure drop at all.

 

Themenstarteram 23. Oktober 2018 um 19:04

Zitat:

@maxmosley schrieb am 23. Oktober 2018 um 20:10:47 Uhr:

...here You find Your car's equipment listed after entering the VIN

https://www.etkbmw.com/bmw/DE/vin/decoder/online

Not sure where to look:

535i N55 (From 01.09.2009)

F07 Gran Turismo Europe

Manufacture date: 01.2010 Steering: L Gearbox: A

VIN decoderParts kits for F07

Model Gearbox Engine Final drive Antifreeze(with AC) Antifreeze Brakes

535i (SN21) 8.50l (GA8HP-45Z Auto) 6.50l (N55) 0.80l 9.30l 0.00l 1.00l

* Final drive (rear axel), Automatic transmission: lifetime oil filing

Themenstarteram 23. Oktober 2018 um 19:09

Zitat:

@RobinDerRetter schrieb am 23. Oktober 2018 um 20:06:30 Uhr:

Use a white paper tissue to cover the end of your exhaust system, when the motor is running. If any coolant liquid is burned by the motor, then the tissue is getting wet from steam.

This can mean the main gasket for cylinder is leaking. Maybe only during high motor temperature.

Are you sure this can work? The hot exhaust gas may condense the water in the air too.

am 23. Oktober 2018 um 19:22

The exhaust gas must be without noticeable water. If you cover the exhaust pipe, then it needs to be 100% dry.

You can compare to any other car.

I did a lot of repair in the past. This is proof.

Themenstarteram 23. Oktober 2018 um 20:03

Zitat:

@RobinDerRetter schrieb am 23. Oktober 2018 um 21:22:57 Uhr:

The exhaust gas must be without noticeable water. If you cover the exhaust pipe, then it needs to be 100% dry.

You can compare to any other car.

I did a lot of repair in the past. This is proof.

Ok, I'm going to try. Hopefully the amount of consumed coolant will be enough to make the paper wet.

What do you suggest: should I do this after the engine reach the working temperature or right after the start?

am 23. Oktober 2018 um 20:04

After engine reaches temperature

Deine Antwort
Ähnliche Themen