Temp Gauge (kinda long, sorry)

[biggene]

Ok, I tried searching and didnt find the answer I was looking for so here goes.

I have an 88 LX that I have changed the following on radiator, water pump, thermostat, radiator fan coolant sensor, coolant temp sensor (underneath intake manifold), radiator hoses, and the little vacuum valve thingie on top of the thermostat housing. My freaking temp gauge still doesnt work correctly, when you a driving it will work for about the first 5 miles, the it pegs all the way at the top, then after driving about 20 more minutes or so, it goes back to where it should be registering. AT first, I thought the car was overheating, thus the changing of the entire cooling system, but it never does overheat. It is almost like the temp gauge has a ground fault somewhere, but I dont want to tear the dash apart if I dont have to looking for a bad wire.

Are there any other sensors I need to change that would affect this, or does anyone have any other suggestions for something to look for???

Sorry for the long rant and thanks for all your help in my time of need :uh:

Gene

[racerx]

sometimes, when you take the gauges out (to repair something, or install reverse gauges), they'll break.
this happens all the time with people who want to put in "glow" needles to go with their reverse gauges.

unfortunately, there is no known remedy for this problem. the best thing you can do is go to a junkyard and buy another gauge cluster. that should take care of it.
most junkyards charge 15-20 dollars for the gauge cluster, and it's really not hard to replace. i've done it a few times myself.

or you can just install an aftermarket coolant gauge. you know, in a gauge pillar. :D

[AZmike]

The gauge in my sedan does the same thing. The only thing in the cooling system that I haven't had to replace yet is the gauge and sometimes tapping the cluster gets it working again so I'm pretty confident that's exactly whet the problem is.

[Sabz5150]

Check your engine grounds. I had the same thing happen to my car when I switched the grounds around. The needle would peg itself at the top and then slowly come back down. The engine was fine.

[DanG86LX]

BIGGENE,
Ur temp gauge behaves like the wire coming from thermosensor touches some ground..
It could be anywhere, at thermosensor, harness or gauge cluster. Most likely dirt @ thermosensor.
Since ur car is LX (i.e. carb) this thermosensor is located under intake manifold, sort of pointing to driver, quite difficult to get to, let alone check, inspect..
Good luck.

[Ace]

after installing my reverse gauges my tach no longer works excuse for me to get a aftermarket one LOL

[w261w261]

This is just a shot, but when you refilled the cooling system, did you bleed it out by the thermostat? Would an air bubble temporarily trapped there cause the sensor to read hot, then as the bubble dispersed, it would come back to normal?

[biggene]

Yes I bled it at the thermostat. I think I will try to find a gauage cluster next week and install it and see if that helps.