Okay here's the deal. 2012 Chevy Cruze 1.8 manual
I've had this car for about 7 years now. I've changed the thermostat like 4 times already.
In 2019 the car over heated and prompted me to shut the engine off. I took it to the mechanics they told me it had a coolant leak and the head gasket was blown. They put some sealant and that seemed to have fixed it. Coolant temperatures remained steady at around 210, never really dipping or climbing when in traffic.
Fast forward it's 2 months ago. I noticed oil in my coolant reservoir. "Uh oh that's not good" I knew this had to mean the head gasket was bad. But before changing it, I replaced the oil cooler in the slim chance that could have been the culprit. It wasn't. Oil still continued to accumulate in the reservoir. I took off the engine head, had it machined, and replaced the head gasket. Obviously I clean the engine block and didn't notice any cracks or anything.
Now by this point the coolant had turned into a milkshake. So I flushed out the system like 3 times, took off all the hoses and cleaned them, and changed the radiator.
Now I know there would have had to have been some more oil residue in the coolant system (the cooling jackets in the engine, the oil cooler, and the heater core). So I know it's not 100% clean but there still seems to be some oil accumulation in the coolant reservoir. It's a thin dark film of oil sitting on top of the coolant. I've been sucking some out with a turkey baster to get rid of it.
What else could it be? Idk if it is still leeching oil into the coolant system it could also be residue but idk anymore. I guess I could do a test with those color changing test to test the head gasket but I don't own one.
Now pt 2 to my problem. The coolant temperature.
Like I said the coolant temperature use to hover at 210. I know these cars like to run hot. But after I changed the thermostat for the 4th time. The coolant temperature has been much lower at 200. Only when I am in slow moving traffic, the temperature rises back to 215,220, I've seen it get up to 230 before it finally go back down. Idk if it's the thermostat that just decides it doesn't want to open. Or if the fan isn't doing it's job properly.
The fan speeds up and slows down. But I suspect it only has high speed and off. I know the resistor on these fans tends to go out and leaves it with no low or medium speed. But I hear the fan kick on while I'm in traffic. I've tested the relays and the are operational. My final attempt is going to be to change the resistor on the fan.
WTH is going on?? I just can't seem to figure out and I no longer want to keep throwing money at it if there's no solution in sight.
They put some sealant and that seemed to have fixed it.
As you discovered, "sealant" doesn't "fix" anything. It's just a temporary band-aid that may not work at all and can plug up your cooling system.
Did you have the head tested for internal cracks when you had it off? It's also possible for the engine block to crack internally but that's less common.
As you discovered, "sealant" doesn't "fix" anything. It's just a temporary band-aid that may not work at all and can plug up your cooling system.
Did you have the head tested for internal cracks when you had it off? It's also possible for the engine block to crack internally but that's less common.
yeah they told me it would only temporarily address the issue. Granted this was at 160k and it finally gave out at 220k so not too terrible. I had the head pressure tested and they told me no cracks in the head.
Granted this was at 160k and it finally gave out at 220k so not too terrible.
Not bad, you lucked out there.
I had the head pressure tested and they told me no cracks in the head.
Well the oil is either getting in somewhere or left over from the bad gasket and you still have cooling system issues. Maybe reverse-flush the cooling system real thoroughly if that hasn't already been done?