Quick question on a 91 GTA 5.7

When my car is cold the gauge for temperature shows about 180 and when the car runs and is at temperature it show 215. Would putting a new coolant temp sensor in remedy the problem or will I have to pull the gauge cluster?
My oil pressure is screwed up too; it hows over 60 psi and sometimes it will register 40 then bounce past 60 again. 2 questions in one thread, sorry. Any help appreciated before I start throwing money. Funny how I know so much about other areas and then get stumped at the little crap.

 

A new coolant temp sensor would not hurt but as the gauge isn't reading below 180 cold I doubt the temp sending unit would fix it. I would think that the gauge may be broken.
For the oil I would start with a new sending unit as it may be reading properly but just getting erratic signals. Thankfully the sending units are relatively cheap.

 

Thanks for the help, the coolant temp sender that feeds the gauge, is it located in the front of the manifold or between #1 and #3 cylinder?

 

I could be wrong but I believe the coolant temperature sending unit is towards the front of the driver side head between #1 and #3 cylinders. The passenger side sending unit should be for fans.
I haven't worked on a V8 in a while but am wanting to do a 350 TPI/T56 swap later.

 

Yes. Between 1 and 3. Doubt it's the sending unit. With the connector loose the guage should read near its minimum setting. With it grounded it should max out.

These guages were never very accurate from the factory though, so your guage's behavior may be as good as it's going to get.

 

Thank You Naf for clarifying how the gauge works. I was confident I was right in my reccomendation but never hurts to be reassured. I do agree that he most likely does not have a sending unit problem for the temp.
I have found that on all cars that the temp is pulled from the head that there is some temp difference between what is being read and actual thermostat temps of about 15 to 20 degrees. However it is still a known fact that these gauges were not the most accurate.

 

If steam isn't bellowing out from underneath your hood, it's your gauge. my coolant temp gauge is 1/4 off, my oil pressure gauge dances, my tach is off, and the speedometer is a little bit pessimistic. You'd be better off replacing all of your gauges and avoiding future problems.

Oh and my fuel gauge is VERY optimistic! I just wish it actually stayed full all the time lol.

 

pull the wires off the senders and see what the gauges do.. then ground them and see what happens.. the gauges read by showing the resistance in the sending unit as it grounds out the wire.

it might not hurt to pull the cluster and clean all the connections on the cluster and in the dash harness with a soft pencil eraser chased with a q tip soaked in rubbing alcohol.. then bend all the little metal tabs up to get them a more solid connection.

pull the sending units out, clean them, and reinstall them without any sort of sealer on the threads. if it isn't fixed by now, then it's time for some sending units.

 

Gonna be replacing the senders tonight hopefully. Man this thing is starting to drink my blood.

 

did you clean all the connections before throwing good money at senders that may or may not fix the problem?

 

I also recommend pulling the cluster and cleaning all the connections. I did this to my iroc and it fixed my problem plus others. I also recomend pulling the wire off the sending unit. It should go to zero with it disconnected and peg full when the wire is grounded. Bad connections at the cluster could also be your problem with the oil pressure gauge. Have you had the cluster out before? I would do this before throwing money at it.