I have a 2001 Monte LS, 3.4. I had a roughly 60 mile interstate drive to do tonight, and near the middle of it I noticed that my temperature gauge was all the way at the bottom of it's sweep...when I start the car the guage still sweeps a few MM down to the base, then comes back up to it's 'zero' point, but it wouldn't go over that. It was 45 degrees or so out, and once I pulled off the interstate I was stuck at a light for a couple minutes and it didn't budge.

The heater was blowing hot, the coolant was at the proper level in the fill bottle, and the radiator fans were on when I parked and shut off the car, the guage just wasn't reading. Does the 01 monte 3.4 have a belt driven or electronic water pump? If the water pump is belt driven and the temp sensor controlling the radiator fans obviously still works, what could the issue be, and is it really detrimental?

I have to take the car on a long road trip next week, already booked the hotels, so I'm trying to figure this out. Anyone have any ideas?

 

Its probably the sensor for the gauge, or the gauge itself. The steppr motors in cluster have a tendency to go out. Only repair if its the cluster, is to replace the cluster assembly.

 

The needle does tick down on start up with the rest of the needles when the gauge resets itself...would it still do that if the stepper motor went out?

 

My car did this too for a while, sometimes the gauge would work, sometimes it didn't. I also have an Aeroforce gauge, and the Aeroforce would still read the correct temp from the PCM, so obviously the sending unit still worked in my case. I'm pretty sure mine threw a code too, is your check engine light on?

I honestly never figured out what the problem was, because it started working after about a month of doing that and never had any problems since...

 

Yes, check engine light is on, but it came on before the gauge problem started. If the thermostat is stuck closed and the water isn't flowing out of the motor I don't really want to drive it around too much. It's cheap enough for a new thermostat and a gallon of coolant but I really don't look forward to the 5 hours I'm sure it'll take me to swap it out.

 

Changing the thermostat shouldn't take longer than 30 minutes, probably including bleeding the system of air.

Go to Autozone and have them scan for codes to find out why the check engine light is on.

 

On the 3.4? Everything I've read says you have to remove the throttlebody and air intake piping, or else remove the exhaust crossover pipe. I've looked at it, and there's absolutely no way to get at it without removing one of those two things. It's boxed in by the engine and x-over to the sides and the throttlebody above it.

 

Ah, forgot about it being the 3400, my bad. I would have no idea on that engine.

 

So I got the stuff to do the thermostat...my question is, theoretically...I know the water pump is working, I know there's coolant, and the thermostat is a mechanical device. So if I rule that out as the cause, it would mean the gauge not working is just a gauge or sender issue. Assuming that, would there be any issues in driving it given that the pump and thermostat are working and the coolant is filled and bled? Obviously other than the danger of the car ACTUALLY overheating without me knowing.

 

Get your car scanned for codes, it's free. The code could be that your car never gets up to operating temp, which could mean that the thermostat is stuck open. Or it might be totally unrelated, but you might as well get it scanned before you do any work either way.