Temperature gauge not working

DisturbedCat · July 8th, 2008, 17:22

I have an 02 TDI Jetta. The temperature gauge is not doing anything. Anyone run into this problem before? I am assuming some kind of temperature sensor has gone bad? Thanks.

Dimitri16V · July 8th, 2008, 17:37

check connector in the back of the head , drivers side.

2004STARWARSTDI · July 8th, 2008, 17:58

Check coolant temperature sensor.

DisturbedCat · July 8th, 2008, 18:16

Ah yes, I bet it is the coolant temp sensor. Thanks for your replies, I appreciate the help.

tdiAlex · July 9th, 2008, 05:00

Slightly off topic.
Is it normal for the gauge to stay at 90 all the time when in actuality the temp reads 100 (via vag)

Thanks

TDIFanatic1.9 · July 9th, 2008, 06:48

Yes VW wrote the code controlling the gauge so that it sits still, not to bother the driver. I've heard stories that when it eventually goes over 90 and up its already too late and damage have already been done. There is some members that changed the rom code that the gauge reads more linear and move with the temp.

tttthumper · July 9th, 2008, 11:49

I believe I'm having the same problem, and just wanted to confirm.

Little while ago (week or so ), I noticed my gauge was not going up to 90. So I switched over my Scangauge and monitored it. SG can show 82, 83,or 84, and my dash gauge was still at bottom left. So I understand it might not be "90", so it doesn't go 1/2 way.

Today I noticed that my Dash gauge went up to 90, even though SG was showing only 75. As my car warmed up to 85 or so, my dash gauge then fell back down.

I understand it might be the temperature sensor, but 2 questions.

What does SG get the # from?

Any harm being done, as the temperature still seems to be up to normal.

Rickstah · July 9th, 2008, 12:14

Just a suggestion...mine was going over the halfway mark occasionally, fluttering back and forth at odd moments. I was going to take it out and replace it when I realized I had the wrong replacement, so in essence I merely pulled it out a little, rotated it some while putting it back in, and added a little di-electric when I plugged the harness back in.

This did something, because my temp gauge went back to registering normal and sometimes just a hair below halfway, and it hasn't fluctuated in about a month or more. Not sure what this means, but it made my fluctuating stop for now. I did add a little new fluid back into the round container after some leaked out, but that was the extent of it.

tttthumper · July 10th, 2008, 06:42

Bump

Still looking for an answer about my last post.
Thanks

HopefulFred · July 10th, 2008, 06:56

I dont know where there may be redundant temp signals (I'm sure someone else knows). On the other hand, if you can't trust your gauges, what good are they? It shoud work properly.

Rickstah · July 10th, 2008, 15:07

bad news

...you can't really trust your gauge in your dash, at least for mine...like feeling your dashboard to see if the engine is overheating...ok, kind of

n8ronJ · July 16th, 2008, 03:46

I hope this is on-topic enough. If it isn't please re-direct me. Lately, my temp gauge shows that I'm running cooler than I should. I'm assuming "should" is at the 190 in the center of the gauge - where it always has been. So, TDI is running a couple of marks below that. Fluctuating when the TDI is warming up but finding a consistant place to land once normal warm-up is achieved.
A couple questions:
Where is the temp gauge sensor? Is it in the reservior for the coolant?
It "looks" as though my coolant level is up to where it should be - if it were too low, would I have this fluctuating gauge issue?
If I'm running low on coolant - I've seen no puddles or drips or excessive steam so where's it going?
Is it time to flush the system anyways? I'm at 82k and climbing. Or can it wait 10k or so until I do the TB change?

JB05 · July 16th, 2008, 13:49

The temp. gauge sensor is both part of the on board diagnostics system as well as the dash mounted gauge. It is located on the left rear of the engine. The newer ones are green in color, and by replacing the sensor should correct any and all gauge fluctuations. That is if your gauge suddenly drops, then the sensor is the most likely culprit as it was on my 05 Golf.

n8ronJ · July 16th, 2008, 14:13

I'll look for it in the left-rear. What is the sensor looking thing that is attached to the overflow canister?
The gauge was acting weird. My drive yesterday was 17 miles and within a 3-4 miles the car is usually warmed up. The temp outside was 80 degrees too. The darn thing was running 2 hash marks below the 190 line. I made my stop and shut the car off for 5 minutes. Started her back up and it's up to the proper temp reading. This morning the darn thing is running around 1 hash mark below the 190 line.

I guess having a bad sensor would make the most sense here. Is a stealership the only place I can get a sensor from?

Rickstah · July 16th, 2008, 20:42

got mine at tdiparts.com, try this link...green or blue is there for yours

http://tdiparts.com/catalog/index.ph...sort=2a&page=3