2008 chevy equinox overheating
 

Help!!! March I bought 08 chevy equinox from dealership. Car fax has 1 owner and all of its paper work as far as manintance goes. Being a single mom 3 kids and always being independant. I put all I had into this purchase. As is cash offer. Landed the truck / suv I thought I always wanted. Yet now for the past 2 weeks I have literally busted every knuckles knees have more bruises cuts then should.cussimg fuming as self. Wondering if.inmade mistake. Called GM with everything im.bought to say and the parts department said and I quote you Mr Brandon in Gainesville "ma'am you've done all this your self then you know more then I do. However I have no advice no recalls or thoughts except to.start over I missed something" . Now yes fuming mad 3 dealerships later can't count friends some.back woods mechainc's cant seem to find a.solution. yet everyone is believing as I do not blown heads. Now that all.said.

Being so proud of my vechile. This now has me so hurt and disgusted with my own self. So here it goes. First time truck ran hot I was at red light. I immediately turned into a store checked coolant it was low. Great. No issues for while. Then bout 2 weeks ago it ran hot. Started saying a/c off engine hot. I pulled into church and pulled theromstat out. Thinking that was my issue. Yet still over heating. Replaced it. Again heating. Then I changed water pump temp sensor theromstat 3 times to point I have it out now. I pulled radiotor no.leaks. circulating fine. Bought a obd scanner came up with P0405 code. Egr is what I'm getting for that code. Maybe wrong there. Yet i can't see that causing heating issues. Next I drained everything using air compressor trying to force push fluids for any signs of leaks. Nothing. Pulled hoses sunk them in tub no bubbles leaks. Not to.mention can't count times I've opened bleeder valve bleed air. I'm at a flipping stand still. I pulled plugs no oil water on them. Changed oil it looks great.

NEVER the less my little 4 ft 11 self is asking for any advise. Also yes I changed the cap. I don't wanna believe heads for.im.not seeing any signs of this. Except bubbling in resiovor. However no leaks not.loosing.coolant...Please and thank u.

can you get/borrow a cooling system pressure tester or a compression tester?



-If the overheat condition happens only when stopped and is ok at highway speed...its could be a fan issue.
-if the issue happens all the time...you need to do some tests to rule stuff out.

if the system uses a surge tank (pressurized reservoir with a pressure rated cap) you should get flow thru the tank. It will pressurize as it heats but if it pressurizes quickly...you may have head gasket issues.
this can be checked by:
-installing a cooling system pressure tester and pump it up to the cap pressure rating....watch for a pressure drop and inspect for external coolant leaks. if the system can't seal itself it will overheat at normal operating temperature. If no drop or leaks release the pressure and reinstall the tester.
- start the engine....if the pressure builds fast over 18psi...that not normal. you need to do a compression test or remove the spark plugs and inspect for coolant in the combustion chambers. a boroscope will allow you to see into the spark plug holes for the presence of coolant.



-option 2 they make fluid testers that measure presence of combustion gases in the coolant. They cost $70 and the test fluid will change colour is gases are present...indicating a head gasket problem.
-option 3 is a compression test...a bad head gasket will post low readings.

check the radiator ….there should be temperature drop of 10*C from the inlet top hose to the lower outlet hose. clogged rads will have hoses the same temp.

you have changed the thermostat so its ruled out...the only other issue is....does the water pump move coolant thru the system? did this problem start after a belt change? did the belt get put on wrong and rotate the pump backwards

to test the fan/s
with the engine cold unplug the coolant temp sensor, this should kick the fans on.
if they (not sure if you have one or two) turn on then move on to what tech has suggested.

but after you refilled the coolant the first time were you low again the second time?