Chevy Equinox Gauge Shows Overheating

Question:
Intermittent problem - temperature gauge will show car is overheating withing minutes of turning car on... Arm on gauge is all the way up past the red overheat mark!!! The fans are working, the water in overflow tank is not boiling. By time we drive to dealership, gauge shows only slightly over half-way mark. By time mechanic gets to it, it is acting normal again. Should we insist on a new temp sensor? 2007 Chevrolet Equinox Service department at dealership cannot find anything wrong!

Answer:
The thing with the temp sensor, you see, is that if it is faulty, it would be faulty all the time. This is a difficult problem to try and diagnose online. It might be best if you could leave the vehicle overnight at the dealership, so when the mechanic looks at it, it should act up upon starting. If there is an electrical problem, a trouble code could be set in the computer.

You could also have a problem with the temp gauge itself. Since your engine seems to show no signs of overheating, I would assume that it isn't and you have some other issue causing your gauge to spike.

Question:
Hi, I'm looking for the heating core inlet and outlet hook up location on the engine and firewall on my 2001 3.4 Chevy Venture Van WB edition. I just bought this minivan and I have no heat. The engine was replaced recently and was wondering if maybe the mechanic forgot to hook it up. Knowing that when they had the engine out probably bypassed it to test it when out of body before installation.

Answer:
They are located on the center of the firewall, best seen from under the van.

Ok great. I seen a couple of aluminum pipes fastened to the center firewall with no hoses hooks on them ( one just bout 3/4"taller then the other. They look clean as if it was just recently removed so i take it there is more then one heating core. One for the back as well? It does have heat and a/c controls for the rear.

Yes, it does sound like those are the pipes.

Well then that semi good news. lol now to find the out and in one the engine. Would it come directly off the water pump? No. One pipe bolts to the back of the rear clinder head, the other is near the thermostat housing.

Is there anyway I can gitt a online picture showing me the inlets and outlets of the heating system? Sent to my email address?

Sorry, we dont have a pic of those particular things.

Ok. Do you know if I will be able to access the hose. Hook ups myself ?

Yes, you should be able to. They are formed hoses between engine pipes and firewall pipe. If you go to a parts store to get those hoses, they should have a pic.

Car overheats but only when stopped like at a stop sign. 2007 Chevy Equinox. I Changed thermostat but still doing it.

Did you purge the air out of the system after t-stat replacement? Are there any bubbles in the coolant when running?

Yes we did, no bubles.

A common problem is a leaking rear headgasket. When this happens, cylinder compression is forced into the cooling system causing air pockets. When you accelerate or drive at speed higher than idle, the air pockets move, so the engine will cool down. This is sometimes accompanied by no heat from the vents.

So does that mean that I should change the head gasket Or get a new motor ?

If a bad headgasket, it would just need to be replaced.

OK, thank you for the great information !