malibumike

hello yall i have a 2007 chevy malibu maxx lt 3.5v6 and my engine temp gauge stoped working and i noticed that the a/c wasent geting cold i asumed it was two seperate problems but as i was driving the temp gauge started working and the a/c got cold again all at the same time. Then it worked for a while and now its at it again both stoped at exactly the same time. Im pretty sure its a loose conection some were but i cannot find where the two systems connect.I called a few chevy machanics and parts houses and thay all agree that thay must be connected but were is the question if anyone could help it would be greatly appreciated

thanks
Mike

stumpy

I've the same issue, what's the solution?

malibumike

I'm still looking for the solution I can't figure it out have you had any luck

EinST

The "engine temp gauge stoped working" how? The needle reads cold? If so, you may have a problem in the ECT sensor circuit. See if you can get it scanned for what the ECM thinks the engine coolant temperature is at. If it's colder than ambient, you may want to consider a visit to the service department, any GM dealership. Continue driving it like that and the engine will run rich and ruin the catalytic converters.

malibumike

thank you for the reply. The temp gauge will operate normal most of the time but sometimes it will just stop working the needle will fall all the way down then usually a few minutes later it works normal again its like its a lose connection if it was a bad ECT sensor would it be intermittent like that and if so were is the ECT . Thank you for your help every Chevy service department I've called has told me thay dont see how one could effect the other so its been a rather frustrating problem

EinST

The reason I brought up the ECT sensor circuit is that the ECT is one of the parameters the ECM takes into account in the A/C request logic. By "the ECT sensor circuit," I'm referring to the sensor or wiring. Often a wire becomes open inside the insulation right around the bend where it goes into the electrical connector. If you are handy with a multimeter and want me to dig up more information, post the 8th of your VIN so I'll know which 3.5L to look up.

Ansu

Did anyone figure the solution to the "engine temp gauge stop working"? I am having the same problem and would like to know what to do. MalibuMike described the same issue I am having. I would like to know if I need to change my ECT or thermostat or both. Please let me know what I need to do. Any help would be appreciated. Thanks.

EinST

Welcome to the forum. When you say "having the same problem," does your engine coolant temperature needle drop and A/C compressor disengage intermittently without the MIL being lit? And, then, do both start working again while you drive (which is obviously the definition of an "intermittent")?

malibumike

hi i replaced the thermostat and coolant temp sensor and it fixed the problem

mcuadra86

hey mike thanx for the update, i also have the same exact issue with my 08 cobalt. my a/c is ice cold when the temperature is reading but when it goes out so does my a/c. i'm going to change both the thermostat and coolant temp sensor and see if that resolves the issue as well.
thanx again mike