Forum newbie here. Got a Chevy Aveo 5 LT, 105,000 miles (169,000 kms) on it. Problems started a week before Xmas. Engine temperature was 50% lower than normal (engine temp gauge/needle maxed at 1/4 level instead of the usual 1/2 level) and low to non-existent interior heat (-22°F/-30°C here today, so gotta have heat!) Also had a small oil leak. Checked dipstick. It was 6 inches above the "full" line. Took it to the garage. Replaced oil coolant gasket. Did a complete oil change. They "burped" the coolant lines to get any air bubbles out. They also said they had no idea why the dipstick level was so high. Left there, but engine temp still cold, same levels as mentioned above. Took it back next day (and the day after that, too) and they "burped" the lines some more & still same cold engine/low interior heat. Took it back yesterday. They checked the head gasket & they said there was no leak, but the coolant level was low (they topped it up 4 days previous to that). They said they were stumped. It's a small garage, mom & pop-type of operation & they suggested taking it to another garage as they "don't specialize in engine heating/cooling issues". The only thing they did was put a big piece of cardboard between the radiator & the front grill, to block the frigid outside air coming into the engine & to run the inside air on recirculate mode. Drove home & engine temp needle was holding steady at 50% (normal spot) & interior heat was good (1st time since before Xmas). Checked out the oil & coolant levels this afternoon. Coolant was the same, but the oil dipstick level was TOO HIGH AGAIN. Though the last garsge said there's no head gasket leak, I have my doubts as to their competence. Debating whether to take it to another garage (not yet), so asking for opinions here first. Sorry for the info overload, but figured I'd include as much facts as possible. Thanks in advance for your replies.

 

What is a "oil coolant gasket"?

OK so that's not a real mechanic. They're just pretending. You should find a real one.

oil level should not rise. 6 inches high is absolutely bananas.
either someone seriously overfilled it, or the oil is being diluted by something.
If the level on the dipstick was correct at Christmas (checked properly: level surface, warm, but at least 15 minutes after stopping the engine) and it's high again (how high?) then something is wrong and you need to change the oil again. This time look for water or fuel.

Did nobody think to change the obvious things like thermostat and pressure cap?