Thermostat/Gauge question [Archive] - Forum


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11-06-2013, 04:24 PM
Wow hey it's been a while since I visited here. But looks like I'll be back around for a while considering my poor GT has so many new things for me to fix and do.

I moved from AR to CO about a year ago and the climate change has wreaked havoc on my car. Dash is warped, the weather stripping around the windows has warped, etc.

Just a few days ago my Temperature Gauge stopped working.

So the deal is, what would be the best way to trouble shoot this. Just a FYI, my upper radiator hose did blow out on me 2 weeks ago.

I figure since the Thermostat itself is so cheap I should just go ahead and replace it to see if that fixes my issue (I plan on replacing the rest of the hoses and tank as well anyways).

However, after replacing the upper hose without any vice grips, I know even though the part is cheap, it can be a good deal of work to replace that thermostat.


11-06-2013, 04:47 PM
could be the coolant temp sensor if the temp gauge isnt moving

11-06-2013, 07:28 PM
T-stat wouldn't have anything to do with the temp gauge not working. They aren't related. The t-stat is completely mechanical. The temp gauge receives a signal from the coolant temp sensor in the neck on the lower intake manifold. It's always got coolant from the engine flowing past it, so even if the T-stat was stuck closed, you'd still get a reading if the sensor was working.

If the gauge isn't working, it's one of four things:
1) the sensor is bad
2) there is a break in the signal wire somewhere or a bad connection at the plug
3) the output from the PCM is bad
4) the temp gauge in the gauge cluster itself isn't working (bad needle driver)

11-07-2013, 02:55 PM
Ah thanks, I'll take a look at the connector and test the wire.

If that is not the problem, then I can see about the gauge, as I will be getting a new dash anyways (since my current one warped)

Then I might just end up replacing the coolant temp sensor anyhow. I have come to the point were it seems smart to replace all of the cheaper parts that wear out over time. Trying to have this vehicle last me a few more years at least, regardless I am keeping it as a project car for learning.

11-12-2013, 11:32 AM
It was indeed the coolant temp sensor. Had a lot of fun, coolant temp sensor, power steering pump needed a replace, flushed the PS fluid, brake fluid, replaced all hoses and overflow tank, new O2 sensor, went ahead and replaced the thermostat since it was cheap. I really wish this car was easier to work on :/

I am debating whether or not to get a transmission fluid flush at 143k miles.

I did take it to have a block test to see how my head gasket I got replaced years ago was holding up, good news on a pass :)

11-12-2013, 01:05 PM
What are you talkin' about, this car is a piece of cake to work on. lol

Seriously though, new cars and other makes are worse. This car, at least everything is accessible without taking something else off. The PS pump, the alternator, the water pump, the ignition coils... they are all right at the top of the engine and easily accessible.

Anyway, good to hear your gauge is working again. For the transmission, I would drop the pan and drain the fluid, change the filter, and refill with new fluid. I would NOT do a flush though. Sometimes that can cause more problems on older trans that haven't had it done before. Stirs up junk in the trans and can damage old seals etc. I had it done on a grand prix I bought used with 123k miles on it, and the shifts started getting weak. A couple months later it failed completely and I had to buy a reman transmission for $3k.

11-12-2013, 02:05 PM
Ah well I guess that doesn't count for the dash? I heard they are a PITA to work on.

I don't see the cheap and easy fix like I found on these forums working for what I have at this time, it's even seems to be blocking air out of the vents and it's getting cold in CO :(