BimmerFest BMW Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter · #1 ·
Hi all,

Over the last few days I've noticed when the car is warming up its not warming fully to operating temperature and stays stuck at about 70 -75 degrees. If I am stationary, in traffic for example the car temp will rise as normal to about operating temperature but when I drive or if I switch on the blower the temperature drops slightly to about 70 degrees.

Could this be a sign of a faulty Thermostat or another cooling related problem?

Thanks
 

·
Registered
Joined
·
2,360 Posts
Yes, it could be a faulty thermostat.

How long has it been since you have replaced your cooling system? If it has been over 60k miles, I would recommend you consider replacing all of your major cooling components. This includes water pump, thermostat, expansion tank, hoses, belts, tensioners, etc. This is not as expensive as it sounds, especially if you are willing to do-it-yourself. The cooling system is a weak spot for your engine, and can cause engine failure.

:drive:
 

·
ROLL TIDE!
Joined
·
23,979 Posts
More often than not it's your tstat. My rule of thumb is if I have to replace any piece of the cooling system, it ALL gets reaplced.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #4 ·
I changed my Thermostat July 2015 and since then have driven about 22k miles, however I used an aftermarket one, not a geniune BMW one.

The car will warm up to operating temperature fine, however if I am driving above 40 mph and have the heating on at the same time the engine temperature will drop to 70 degrees. Would all of this affect the way the Thermostat performs?

Thanks
 

·
ROLL TIDE!
Joined
·
23,979 Posts
I changed my Thermostat July 2015 and since then have driven about 22k miles, however I used an aftermarket one, not a geniune BMW one.

The car will warm up to operating temperature fine, however if I am driving above 40 mph and have the heating on at the same time the engine temperature will drop to 70 degrees. Would all of this affect the way the Thermostat performs?

Thanks
Yes, your car does that because the tstat isn't closing and the coolant is staying cooler than it normally would. Turning on your heat further lowers engine coolant temp. Mileage on aftermarket parts means very little, especially if you use crappy coolant. They can and do fail quick sometimes. I'd change the whole system if you haven't already.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #8 ·
Changed the thermostat last weekend as well as doing a full coolant flush and bleed. Seems to have worked with the temperature staying steady at circa 95 degrees.
 
1 - 8 of 8 Posts
Top