Gauge Trouble

all right guys, you have to help me here, cuz gm refuses to give me support without paying them, i bought a 1994 cavalier RS convertible with 3.1 V6 in it for 750$, not a bad price eh? well my speedometer is jumpy, it'll move, but against it's will, in order to get it up to the speed i am at, i have to deliver a good whack to the dash board, might be broken yes? my major problem is finding a new one.... IMPOSSIBLE! and another issue i have, is my temperature gauge is all over the place! one second it's sitting at 180 degrees, then it's at 200, then it's down to 120 i mean i can never pin point it, the thermostat is fine, the fans kick on when they are supposed to and the engine runs smooth, then there is the tach, that freezes when it seems to feel like it, mosty not on the street, but my favorit is when the tach and speedometer drop to zero and stop working, hmm whats ur diagnosis?

First place I'd look at is a faulty gauge cluster. That could well explain it all. Your best bet is a junkyard. Just go find yourself any 91-94 that has a tach in the cluster and pull that sucker out. Its a very easy swap just needing a few torx bits (20 or 25, if memory serves) and your average tools.

Although, for reasons of accusations of tampering, I'd go ahead and check all the sensors, see if any are stripped wires or what not.

I also had a jumpy temp gauge on my old Z24 with the 3.1. Fixed that with a new thermostat. Just be very careful taking replacing that, that tube on top of the thermostat housing snapped when I replaced it.

all right guys, you have to help me here, cuz gm refuses to give me support without paying them, i bought a 1994 cavalier RS convertible with 3.1 V6 in it for 750$, not a bad price eh? well my speedometer is jumpy, it'll move, but against it's will, in order to get it up to the speed i am at, i have to deliver a good whack to the dash board, might be broken yes? my major problem is finding a new one.... IMPOSSIBLE! and another issue i have, is my temperature gauge is all over the place! one second it's sitting at 180 degrees, then it's at 200, then it's down to 120 i mean i can never pin point it, the thermostat is fine, the fans kick on when they are supposed to and the engine runs smooth, then there is the tach, that freezes when it seems to feel like it, mosty not on the street, but my favorit is when the tach and speedometer drop to zero and stop working, hmm whats ur diagnosis?

u can also check the cluster for loose wires

and besides junk yard u can look at ebay