View Single Post
Old 01-19-2010, 01:07 PM
nyclad's Avatar
nyclad nyclad is offline
Officially Welcomed to the 'Fest
Location: Orange County, CA
Join Date: Dec 2007
Posts: 477
Mein Auto: 2002 530i Sport
Originally Posted by Panzerleutnant View Post
You know I have a similar problem, this morning the car went straight through the red... like it should have exploded, according to the temp gauge, but when I stopped to check it out, nothing seemed to be wrong, so I started it back up and it had corrected itself, so i continued to drive and it hasn't happened again. So, correct me if I'm wrong, but i'm thinking that it's the temp sensor that's rusted over or gunked up... does this make sense to anyone? If so, can you point me to how to get at the temp sensor in the rad?

I had the same problem a few months ago, every now and then when I first started up in the mornings, it would go all the way into the red within 30 seconds of driving off. I'd pull over and shut off the engine and let it sit for a minute, and it would be just fine when I started it up again.

I also noticed on other times, it would take forever for the reading to get to normal operating temp. Usually when I pull into work (13 miles away by freeway) the needle would be barely in the normal operating temp, but on the cool side. I also had a P0128 code a few times, indicating coolant temp below operating levels. I cleared it the first time, thinking it was just because the engine was cold, having just started up.

After reading through these forums, I decided it was a thermostat going bad, but fortunately mostly jamming open (cooler) instead of shut (hot.) After replacing the termostat (not the temp sensor,) I had no such problems. The temperature needle goes to 12 o' clock (and stays there) usually within 1 minute of starting up and driving (versus 13 miles with the old thermostat.)

Do you have any codes (pending or currently active) for the coolant temperature?

Last edited by nyclad; 01-19-2010 at 05:55 PM.
Reply With Quote