Originally Posted by Eq1973

Ok here is a run down of everything I have tryed on it.the equinox starting heating up and it blew a head gasket when I went to put on the head gasket it also had a cracked head so I replaced the head and both head gasket.and i also replaced the water pump and a new thermostat and bleed out the air it does good for about 15 mile drive an then it quickly heats up and when it heats up my heat inside the vehicle stops working.and the antifreeze lever drops down really low. I’m not sure what the problem is I will be trying a new coolant cap tomorrow.any suggestions would be greatly appreciated if the coolant cap doesn’t fix the problem I don’t no what else to do.my fans seem to be working properly.

Originally Posted by tdwilson

I have a 2008 Chevy Equinox AWD, 3.4 V6

The weekend before 4th of July my car started having overheating problems it would be fine and then all of a sudden it was overheating and warning alarms were going off and giving me a warning on the dash saying "ENGINE HOT A/C TURNED OFF" and "ENGINE HOT IDLE ENGINE". The first time I got this warning I was waiting in the drive-thru. The second time it happened I was backing into my driveway after driving home from the store which is only 2 maybe 3 miles away. When I stopped and turned off the engine it dumped antifreeze out the overflow, and you could see a trail on the driveway from me backing up. On an important side note my thermostat gauge on my dash hadn't been working correctly for a while; it worked here and there. Sometimes the gauge would read like normal, sometimes it wouldn't read or move up at all and one time it went all the way to the top past the red, but the car wasnt overheating. Also I had been getting a "TRACTION CONTROL OFF/SERVICE STABILITRAK/ STABILTRAK OFF" warning as well.

At this point we changed the thermostat and flushed the system. Still had the same issue. We then changed the coolant temp sensor. Again still the same issue and warnings. Then the serpentine belt was replaced and then the water pump. Still not fixed, all issues are still happening.

So we borrowed a scan tool from a friend to read the codes on my car and it gave 6 codes:

-P0403 Exhaust Gas Recirculation Circuit Malfunction
-P0404 Exhaust Gas Recirculation Circuit Range/Performance
-P0405 EGR Sensor A Circuit Low
-P0442 Evaporative Emission Control System Leak Detected (small leak)
-P0455 Evap System Large Leak Detected
-P0469 Purge Flow Sensor Circuit Intermittent

So at this point we ordered the EGR valve as that needed replaced and has seemed to fix the issue on the first 3 codes P0403, P0404, and P0405; I also no longer get the "TRACTION CONTROL OFF/SERVICE STABILITRAK/ STABILTRAK OFF" warning going off and it previously would usually go off within a block or two. But we are still having the overheating issue, we have not driven it to the point to get the overheating warning to go off again though because we don't want to continue to overheat the engine. Although we can let the car run in the driveway for an hour and it won't overheat, we did this several times while trying to bleed all of the air out of the cooling system, and have been able to since the issue started. However if you take it out for a drive you can't really go further than 5 miles without it overheating and getting the alarms and warning on the dash.

We have thought about the possibility of a head gasket the car isn't really showing any signs of it being a head gasket, no white smoke or anything out the tail pipe and the oil is fine, not milky or anything. But could still be a possibility.

Also I'm pretty sure the P0442 and P0455 and possibly the P0469 are going to be covered on a recall on it, I have a letter for it cause my car was a "may be affected by it" list. Cause it had seemed like I had been smelling some gas, so with those codes and the letter I think that's covered and most likely not affecting the overheating issue.

So the following is what we have done:
-Replaced Thermostat
-Flushed cooling system
-Replaced Coolant temperature sensor
-Replaced Serpentine belt
-Replaced Water pump
-Replaced EGR vavle (this fixed the service stabilitrak/ traction control warning)

Also both of my fans are working and kick on. The first one will come on when it hits the halfway mark and then when it starts to to get really hot, the second fan kicks on, so pretty sure I don't have a fan issue.

I'm not really sure where to look and what to check next, PLEASE HELP!

Thank you!

Originally Posted by xmycoolx

I had the same issue begin also. Seems to be a VERY common problem for this vehicle. It started about 2-3 months ago with all of the same symptoms as everyone else. I noticed a blown intake manifold gasket on the lower manifold. I replaced that as well as the upper manifold and checked all clamps and anything else that may cause a leak upon reinstallation. Next, I ran a pressure test on the reservoir to determine if there was either another external leak or an internal leak. Fortunately, in my case anyway, I didn't lose any pressure so I eliminated any head gaskets or internal leaks as well as external. I haven't had any white smoke out the *** while idle or drive. I then flushed out the radiator and simply just ran water through all the hoses making sure they have flow and aren't obstructed. The heater coil didn't seem blocked up and it flowed. The water that flows through the pump to the thermostat and back to radiator didn't have any obstruction. The radiator also did not have any obstruction. Everything seemed fine. I replaced the water pump also just because it wasn't too expensive nor difficult so why not. I also replaced the reservoir cap and bled out any air that could be in there. After everything I just took it for a drive a moment ago and after I parked and let it sit it began to run hot and it flipped that engine hot/ac off code again. I've had it reduce power on me before on the way to the grocery store and thats what began my dismantle and replacing of EVERYTHING. It's, unfortunately, not something you can continue to use this vehicle with. At least not until someone happens to pinpoint what could be wrong.

I will say this for my vehicle...When the car is warmed up and I'm waiting to see if it will overheat, it doesn't feel like there is any water in the hoses flowing through the engine. It's almost as if there isn't any pressure or the pump isn't working...But seeing as Ive changed the pump and ran a pressure test without losing pressure I can't think of what would keep the water from circulating. Best of luck!