It happened again, less than 1 year and new thermostat later. The first occurance was while I was slowly climbing 10 levels to find parking in a garage (crazy, right?)
This time I noticed that the engine temps are rock steady when I’m driving, but a long idle at a traffic light sometimes causes the gauge to start moving. If I turn off AC and stop the engine for a minute, the gauge returns to normal on restart.
Any guesses? Another bad thermostat or something else causing the engine fan to malfunction?
Idling these cars is bad. How hot is the weather? It still shouldn’t do this though. What else have you replaced in the cooling system? Not sure if your t-stat might be faulty, what cels are showing?
This time last year I changed the thermostat and coolant expansion tank, plus a complete coolant flush. Before that I replaced the whole water pump assembly. Also the AC compressor…
Pull the coolant and have it inspected or tested. From there check your rad units to make sure that all of the fins are not mangled. After that unplug your ECU’s … make sure the battery is unplugged and then plug back in the battery. Make sure your fans kick on and are getting up to full speed. You will be able to tell if they are working upto full speed if it sounds like your car is going to take off.
After you have checked those things the next likely thing to replace and check is the thermostat.
I actually got smacked on the right side by a truck a couple of days ago so I just dropped the car off for a little bodywork. I’ll check it out when I get it back.
A second possibility is that your cooling fans may not be turning on. I had this problem when I had a 2008 G8. Temp would start rising while idling. Turned out that when I had done some work on the car, I had forgot to plug the cooling fans back in.
I had some insurance work done the past few weeks and finally got my mechanic to look at this issue. He said the engine fans check out and hebidles the car for 30mins but the coolant temp was steady and he was unable to replicate the problem. Next step is for him to find time to drive it around in traffic for awhile. Any over suggestions—or should I just replace the thermostat and hope for the best?
you can test the thermostat and see if its opening. but that would take a bit of work. The fans checking out is a good thing. You just want to make sure they are kicking on and working when they are suposed to. They might work but the sensor that controls them might not work properly that would be something to check into as well
My mechanic checked the fans, they were all working properly. He idled the car for 30 mins with the AC on but the coolant temp was steady. I bought a replacement from ECStuning and had him replace the thermostat, anyways.
I just got the car back so I’ll keep an eye on it. But the outgoing thermostat looked just fine.
what do you mean “looked” fine?
Did you try boiling to see if it opens at its desired temp?
It has a heating element making it a map controlled Tstat, but at the end of the day it is still just a regular ol wax pellet Tstat
Just to follow up on what greg said. There isn’t a good chance you can just look at the thermostat and see if its bad. You would need to test it. I guess time will tell if that is the fix. As the car will either over heat or not now.
