2004 H2 Engine Temp Gauge goes Nuts

[Olfart]

I checked codes and there are no problems shown. As far as as the thermostat goes... the engine is not overheating the gauge just reads too high a temp. And after the H2 sits overnight and is definitely cooled down the temp gauge will read about 200 degrees when ign is switched on. It will continue to climb slowly to the far right as the engine heats up. Then the next morning it will read properly until it decides to screw up again which could be a couple of days or weeks. So I'm suspecting a bad sensor or a bad gauge, but am looking for any other suggestions before I take it into the dealer because warrany expired in Sept and so the $$$ will be on me

[Easy Ed]

Circuit description (2003 Service Manual)
The powertrain control module uses the engine coolant temperture to monitor the engine for an over temperture condition. This condition occurs when the coolant temperture is above 132 degrees C (270 degrees F). When an over temperture condition is present, DTC P1258 will set. Blah, Blah, Blah

With it not having a code I would say it would be the gauge.

Another thought, wasn't there some problems with insturment panel clusters and the gauges acting up mentioned on here before ?

This one is about the speedo. http://www.elcovaforums.com/forums/s...strument+panel
Same here speedo http://www.elcovaforums.com/forums/s...strument+panel
Complete cluster not working http://www.elcovaforums.com/forums/s...strument+panel

Not found any on the temp gauge though ?

[Olfart]

It now looks like it's the gauge that's bad since it reads all over the place and the engine isn't running hot. Even with the engine cool....sit overnite...it reads about 200 degrees. Since this will most likely involve replacing the whole instrument cluster I think I'll just ignore it until some other gauge in the cluster goes wacky.
I rescanned again today with the engine both cold and hot and there are no codes coming up bad.
If I do happen to get an overheat condition it will throw up a code and I will get a warning on the DIC. Since I don't overload the engine....h'way driving only...and a few dirt roads to my house...I think I'll be safe doing it this way.
Any comments for or against would be appreciated

[Easy Ed]

If ya can live with it But there are places that can repair it, here is one on eBay http://cgi.ebay.com/ebaymotors/2003-2006-GM-HUMMER-H2-SPEEDOMETER-CLUSTER-REPAIR_W0QQitemZ320447790067QQcmdZViewItemQQimsxZ2 0091112?IMSfp=TL0911121910008r20941

Your call,
Ed

[Olfart]

Thanks for the link, Ed. I'll keep it in mind. Right now isn't a good time to shut down the H2 even for a day or two.

[Easy Ed]

No problem

Originally Posted by Olfart

Thanks for the link, Ed. I'll keep it in mind. Right now isn't a good time to shut down the H2 even for a day or two.

[vandy0090]

id prob run an aftermarket gauge and mount it somewhere but thats just me i wouldnt want to trust that the dic is going to do its job