2G Compression Numbers

[cornboy]

Hey I'm sorry if this is a bit redundant but I wanted to get y'all's input on my eclipse.

Trying to decide if I should have it rebuilt or not, ran a compression test (though it was cold) and got 185/170/180/160, apparently it's a 2.1 stroker with a 9:1 compression ratio.

Is that 160psi something I should be worried about, or within tolerances for the compression, I know the general rule of thumb is 14psi of variance.

Thanks

 

[silvreclips]

You need to run the compression test when the motor is hot. If that cylinder is still lower than the others. You can add a tiny amount of oil to the cylinder to see if the numbers go up. That would indicate worn rings. It's not something I would be overly concerned with. I do a compression check once a year and compare those numbers with previous years to give me some idea on how motor is doing.

 

[cornboy]

Fair, I just bought the car a few months ago and am in the middle of replacing the entire cooling system, so I can't exactly run the engine till it gets warm, but I'll definitely run it again once I get a new radiator and hoses.

 

[jkuga]

I'm not as experienced as most on here, but I did an compression test on my engine without it fulled heated up and got about the same results as you with one cylinder a lower. A while after I did a leak down test with the engine hot and lost virtually no pressure in all cylinders. Just sharing my personal experience here.

 

[cornboy]

Thanks man, I think I'll go ahead and do all the important maintenance stuff first and just keep using the block without rebuilding it. I'm not planning to make much more than 350 crank horsepower so it should be somewhat reasonable.

 

[TerminalTalon]

A 10-15 psi difference is a reason for concern.

 

[cornboy]

A 10-15 psi difference is a reason for concern.

Should I pull the engine and get it rebuilt?

 

[cornboy]

I'm not trying to make massive numbers, in fact right now I just want to get the car driving without weird issues. But if a 10psi difference is enough that like 7 pounds of boost is gonna f*** it up, I'll definitely take it to a shop.

 

[silvreclips]

Should I pull the engine and get it rebuilt?

No, it will be fine. I would not be concerned one bit.