Overheating

uk215m3 · 01-27-2024, 05:02 AM

I thought i should post this to make clear the e92 M3 thermostat can fail in the closed position. Everything i have ever read says it is designed to ONLY fail in the open position.

For reference, i started seeing higher oil temps in normal driving so i wanted to monitor the coolant temp, did so using a bluetooth OBD adapter and my phone.

Coolant was getting up to 106-112*C (225F 'ish) in normal town driving. fan was/is working fine.

System was taking a long time to pressurise. Radiator was barely getting warm if cold, indicating no real water flow.

Today water pump and stat removed, tested the stat in a pot of constant boiling water for about 10mins, moved approx 1mm if that. New stat fully opened in less than 2 mins.

Just in case anyone else has this same issue.

Helmsman · 01-27-2024, 10:07 AM

Believe first time I saw this, interesting input!

rrkash18 · 02-02-2024, 07:41 PM

I have a 2012 m3 and I am experiencing overheating and I am in New York winter. Did you get any codes for thermostat? And what is the name and part number for the thermostat you replaced?

uk215m3 · 02-14-2024, 03:27 AM

Zero codes. From what i understand you only get related codes due to 'over cooling' all i had was a single overheat waning on the screen to slow down.

Part number: 11 53 7 836 155

Also noted was the rubber gasket disintegrated on removal.
Was also slight play in waterpump bearing.

01-27-2024, 05:02 AM	#1
uk215m3 New Member 18 Rep 19 Posts Drives: e30 M3, e92 M3 Join Date: May 2022 Location: Qatar iTrader: (0)	Overheating - Thermostat failed closed. I thought i should post this to make clear the e92 M3 thermostat can fail in the closed position. Everything i have ever read says it is designed to ONLY fail in the open position. For reference, i started seeing higher oil temps in normal driving so i wanted to monitor the coolant temp, did so using a bluetooth OBD adapter and my phone. Coolant was getting up to 106-112*C (225F 'ish) in normal town driving. fan was/is working fine. System was taking a long time to pressurise. Radiator was barely getting warm if cold, indicating no real water flow. Today water pump and stat removed, tested the stat in a pot of constant boiling water for about 10mins, moved approx 1mm if that. New stat fully opened in less than 2 mins. Just in case anyone else has this same issue.
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01-27-2024, 10:07 AM	#2
Helmsman Major General 4468 Rep 7,113 Posts Drives: 2011 AW E90 M3 ZCP Join Date: Mar 2014 Location: Stockholm, Sweden iTrader: (0)	Believe first time I saw this, interesting input!
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02-02-2024, 07:41 PM	#3
rrkash18 Registered 0 Rep 1 Posts Drives: E92 m3 Join Date: Feb 2024 Location: New york iTrader: (0)	I have a 2012 m3 and I am experiencing overheating and I am in New York winter. Did you get any codes for thermostat? And what is the name and part number for the thermostat you replaced? Last edited by rrkash18; 02-02-2024 at 08:26 PM..
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02-14-2024, 03:27 AM	#4
uk215m3 New Member 18 Rep 19 Posts Drives: e30 M3, e92 M3 Join Date: May 2022 Location: Qatar iTrader: (0)	Zero codes. From what i understand you only get related codes due to 'over cooling' all i had was a single overheat waning on the screen to slow down. Part number: 11 53 7 836 155 Also noted was the rubber gasket disintegrated on removal. Was also slight play in waterpump bearing.
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