Originally my CEL came on and through a code about the Coolant Temperature Sensor not reading correctly, or not operating at normal temperatures don't know if there's two or if that was the screen explaining what it meant. Regardless, I replaced the Coolant Temperature Sensor, the one on the passenger side behind the engine.

So far, no CEL but now my temperature gauge is changing from normal to cold depending on the conditions.

It starts up and warms up normally, Cold to normal. Stays steady at normal (middle of the gauge)

When driving it drops to just above cold, but the heat is still warm.

When stopped for a decent amount of time it goes back up to normal - dead center no moving.

This happens consistently, it's actually weird because when driving between towns, the warmer town read slightly higher then just above cold, almost middle of the Cold - Middle range but in the colder town it ran pretty much just above cold.


With no CEL I'm confused, my next guess would be the thermostat isn't working properly but the car isn't overheating and the heat is working correctly.

Any ideas?

 

That is an interesting problem report.

What I read into this is that everything is normal until you drive on the highway for awhile (and the temperature gauge then drops to closer to “Cold”).

Is that correct?

If that is the case, no problem, especially if your car’s heater is working correctly. The problem is likely the thermostat. The fan is probably running when it should not.

Try replacing the thermostat.

--Spike

 

That does sound like the case.

I'll try doing that tomorrow and see if it fixes it.

I'll post an update incase anyone else runs across this issue.


- UPDATE

Actually when I was driving before, the temp gauge wasn't climbing at all, but the heat was getting warmish then when I really got going the heat turned cool and the gauge continued to not budge and then the CEL came on.

So, probably the thermostat definitely. Going to fix it tomorrow hopefully and see if that fixes everything.

 

Temp sensor was removed, air now in system, bleed be coolant.

 

I tried bleeding the system before changing the thermostat but that wasn't the problem there was no air and it didn't change any of the problems. So i hunted down this elusive dealer only part that no dealer in a 50 mile radius carries, APW (auto parts warehouse) is awesome!

All the hoses on that damn thermostat were like pinched to **** and nearly melted on from those death grip hose clamps btw turned an hour or two job into a very cold 5 hour ordeal in the dark.

The old thermostat was broken it was stuck open. So after fixing it and burping the coolant for a couple of hours this morning it seems to finally all be fixed.