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Q: Overheating

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Okay so today I did the compression test on the car and I'm kinda scared and stumped at the same time most of the cylinders where about 130 to 135 and the 2 on the the front cylinders 1 and 3 where 120 the first time I did the test and I let then sit for a couple minutes but I did the test again and cylinder 1 got to 135 and held it and cylinder 3 would only get to about 125 I also looked for bubbles coming through the radiator and nothing from any of them when I took out the spark plugs they looked good on the front head and the back ones looked kind of oily when I took the 2 cylinder the first one for the rear head it was kind of hard to get out and looked like it was burning coolant and smelled odd and different from the rest the other ones the rest smelled like gas I thought it was a head gasket leak because the symptoms are the car will run good for a couple of days after I bleed the air out of the system and after like after 3 days it will overheat again and it bubbles at overflow

My car has 110000 miles.
My car has an automatic transmission.

A: When you put pressure in the radiator you a...

When you put pressure in the radiator you are only going up to about 15 psi, but when a cylinder fires, it puts out a lot more than the compression test showed at 125 psi. This is why you are only getting pressure in the radiator while running the engine. You most likely have a blown head gasket on the cylinder number two. When you remove the intake manifold and heads on both sides, check the corners to see if the head and intake is not rotted away and needs replacement. Your compression looks pretty good so you have good pistons. Your best bet may be to have a trained professional come to your car’s location to pinpoint the fault in person and diagnose the cause of the overheating issue.

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