Compression test - High compression in one cylinder

Hi fellas.

 

Some background info- 2007 2.5i, 104,000 miles. I've been burning a good bit of oil between intervals, but no worse than the specified allowance. On my last oil change, I noticed that the oil was low, and also light brown, thin, and a little bubbly. It didn't smell of coolant, but oil doesn't look like that any other way.

 

Assuming one of the head gaskets is on its way out, I decided to do a compression test. Results are below

Cyl 2- 180

Cyl 4- 180

Cyl 1- 180

Cyl 3- 210

 

What gives? Do I have oil or coolant in that cylinder interfering with the test? Is the tester reading high and I have 3 low cylinders and one good one? Could one head be torqued down harder in the corner than the others? Am I fine? Should I tear into it anyway?

 

Any help is appreciated, I'm stumped.

Leakdown test

Leakdown was inconclusive, as in not really showing any real problems.

 

I planned on tearing down the engine regardless of the outcome. The head gaskets were replaced this past weekend. The passenger side gasket was in so-so condition. It would have been okay to run for a little longer if I needed it to, but would be causing some real problems in the near future. Drivers side was fine.

 

However, there wasn't anything detectable on that gasket or during the tear down that could explain the high compression on cylinder 3.

 

I did discover that the engine is a LKQ engine. If it was rebuilt, maybe they used the wrong piston? Who knows. As soon as the accessories are put back on and the motor is completely back together I'll do another compression test to see if the issue remedied itself.

if its LKQ prob incorrect piston or maybe a corner cut to avoid milling the crank, unfortunately.