Running Temperature - BMW Forum

mrmojo37 · 11-14-2008, 12:10 PM

I recently purchased a 1997 528i with automatic transmission. It runs great and I love the car but im concerned that the running temperature is too low. The dashboard temperature gauge is always in the blue unless I stop the engine and restart it a few minutes later and then it goes up to the half way mark. Should it run in the blue all the time. Thanks.

grownmanlos · 11-14-2008, 12:18 PM

i would say check the therastat it could be stuck open or the temp sensor either but thats jus a start on somethings that could be wrong im not to sure though i got a 98 528i i think the motors the same...

16valex · 11-14-2008, 04:37 PM

Try unplug the dual temp sensor by the top right radiator near the AC drier. Clean it good and then put it back.

The temp gauge should always be right in the middle 12 o'clock after car has been driven 15 minutes.

mrmojo37 · 11-24-2008, 05:30 PM

AHHHHHHHHHHHHHHHHHH!!!!!!!!. I ordered a thermostat. It arrived today so I pulled the old one. The new one didnt match the old one. It was a single stage unit and the original is a dual stage unit. I had to put it all back together with the old one till I can get the right one.

drz · 11-24-2008, 08:33 PM

SUx that they got you the wrong thermostat, but once you put the right one in there, your issue will be fixed.

540red · 11-25-2008, 04:20 AM

Thanks for this thread, I thought my 540 was running too hot at 12 oclock on the gauge.

mrmojo37 · 11-30-2008, 07:49 PM

Got the right thermostat today and installed. Temp gauge sets steady at 12 o'clock. It did surge to the red momentarily before I bled air out of the system but hasnt moved off 12 o'clock since. Even after some agressive accelleration and a 100 mph run it still stays at 12 o'clock. Im anticipating better economy and cabin heating too. I also replaced a missing outside temperature sensor. It didnt work right away, still read -40, so I disconnected the battery to reset the computer and it works perfect.

Next im going to have the rear rotors turned to fix some pulsating. I isolated it to the rear by pulling the parking brake to check.

Things are looking up. Thanks for all your replies.

witeshark · 11-30-2008, 09:26 PM

Very glad to read about the great progress!

tezza07 · 04-03-2009, 09:26 PM

Hi
The sender on the side of the radiator isn't the dual temp sender it simply switches you auxiliary fan off and on. The dual temp sender is located in the head under the inlet manifold on an M52. It has 4 wires attached; 2 go to the temp gauge in the dash and 2 to the ECU. I had a faulty sender in my '97 528i.