[88MKIIITurbo]

So yeah... starting up my car and at idle, everythings all fine and dandy. But then when it's all heated up and ready to go, revving the engine suddenly makes the temperature gauge needle just fluctuate wildly. It stays at the normal position(a bit below half way), but then when i rev, it just goes all crazy and drops down. When I drive and start boosting, it gets really bad and almost goes down all the way. And then when I'm going through a turn, it just completely drops down all the way.
I tried searching but never found anything exactly like my problem... anyone have any idea??? The car seems to run perfectly fine, its just that that damn guage has me worried a bit...

 

[xms]

Mine did the same thing, change out the guage temp sensor

 

[NeedasupraMKIV]

I have a crazy temp gauge too.....only when mine is warm at times the needle jumps up suddenly and pegs itself at the top and stays there a while and then it comes back down for a second then jumps back up again. I am going to do a full coolant flush and change the thermostat and temp sensor and see if that solves the problem.

 

[catch2nd]

I had the same issue.... i simply cleaned the plug and terminal on the sensor.... have not had a problem since

 

[Larry_A]

The last time I saw a bouncing temp needle was on a kid's MkIII that was about a gallon low on coolant. Air hitting the sensor made the reading fluctutate. He'd called me to take a look at it since he didn't know what to do. It BHG'd after that & he sold it off. Just as well...the kid never took care of the car- drove it 'til it died.

Good luck.

 

[NeedasupraMKIV]

I checked the coolant not long ago and it looked good with fluid in the overflow and everything. The car has done this since i bought it though. Hopefully it doesnt blow the HG on me, that would not be good.

 

[Spoolme]

mine is doing this now. its wierd. but it does it only sometimes. it used to do it a long time ago too.
for me, i think i have a blown cometic head gasket. i even tried retoqueing it to 90ftlbs the other day but still smokes white a little bit on idle and when i punch it sometimes. also its pushing my coolant to my overflow and out of that into the street when driving.

 

[NeedasupraMKIV]

damn.....mine is definately not leaking anywhere. the overflow is right where it should be and the rad is full. I think I am going to do some work on it this weekend and check it out.

 

[Topher E]

When mine did that it was because of a BHG. More like NeedasupraMKIV was saying.

 

[suprra_girl]

since it's soooooooo wacky i would think the temp sensor terminal is naffed or loose