Cooling Issue on E90

[zizebra]

Hi All,

I am hoping someone can help me get to the bottom of my issue. My 2009 E90 Sedan appears to have a problem which seems difficult to pinpoint. The car started showing that it was losing coolant every 3-4 weeks. I could not find or locate any leaks anywhere. I took the car to a ex bmw mechanic who claimed claimed the issue to be on some seals on the car. The issue seemed gone because no coolant warning showed up over the next 5000km. Then radiator cracked just below the upper hose while on a long journey. Luckily i was traveling with a mechanic who managed to seal the crack. However the mechanic expressed that he was not sure that water was flowing correctly. He suspected that the thermostat was not working correctly, because the radiator upper hose seems to be stiff.

Now the radiator was replaced. 1 week after coolant message popped up. The mechanic checked and recommended replacing radiator upper hose. This was replaced but now leak is back on the radiator upper hose again. The radiator upper hose has bulged yet again.

I understand that when thermostat fails, there will be an error message. But there isnt. The car drives just fine except i am losing coolant and the bulge on the radiator upper hose is worrying. Prior to all this engine temperature used to average around 102degrees and now its always 106 -108.

A different mechanic has suggested changing the thermostat. But i need to know what could this issue be.

Where can i get this thermostat and radiator upper hose in Cape Town

 

[momo1]

Maybe take it to silverton and have them check it out for you , they can do a pressure test as well.
I know in JHB they charge about R200 for a thorough test.

 

[CliftonH]

Hi All,

I am hoping someone can help me get to the bottom of my issue. My 2009 E90 Sedan appears to have a problem which seems difficult to pinpoint. The car started showing that it was losing coolant every 3-4 weeks. I could not find or locate any leaks anywhere. I took the car to a ex bmw mechanic who claimed claimed the issue to be on some seals on the car. The issue seemed gone because no coolant warning showed up over the next 5000km. Then radiator cracked just below the upper hose while on a long journey. Luckily i was traveling with a mechanic who managed to seal the crack. However the mechanic expressed that he was not sure that water was flowing correctly. He suspected that the thermostat was not working correctly, because the radiator upper hose seems to be stiff.

Now the radiator was replaced. 1 week after coolant message popped up. The mechanic checked and recommended replacing radiator upper hose. This was replaced but now leak is back on the radiator upper hose again. The radiator upper hose has bulged yet again.

I understand that when thermostat fails, there will be an error message. But there isnt. The car drives just fine except i am losing coolant and the bulge on the radiator upper hose is worrying. Prior to all this engine temperature used to average around 102degrees and now its always 106 -108.

A different mechanic has suggested changing the thermostat. But i need to know what could this issue be.

Where can i get this thermostat and radiator upper hose in Cape Town

Im no mechanic, but the car has 2 themostats, you can get it from golswagen, rather change them both and see if the problem still exist, since you already put a new radiator you can rule out a blocked radiator, if the problem still exist I would bet its your water pump,

 

[zizebra]

This weekend, I drove out about 40 Km out from my place on N1. I monitored the temperature while driving. It took about 20-30min to reach 106 degrees. Then temperature camei down to about 80. Then gradually went up again to 106 in about 5 to 10min. Then came down to 80 again. Thereafter took about 5min to get back 104 and flactuated between 100 and 104 for the rest of the journey. The only thing that I forgot was to compare the temperatures for the upper and lower hose. The same thing happened on my way back.

What is baffling me is the stiff upper hose and the fact that It has never overheated while driving around. If it were not for this stuff hose which seems ready to pop I would not bother looking at it.