SR20det RedTop Compression Test Results

[Newcastle82]

Alright, so my friend and I just did a compression test on his redtop SR20det... and were astounded by the results. All compression tests were performed with the engine warm at WOT.. here are the results.

#1 - 120-125 psi#2 - 115-120 psi#3 - 115 psi#4 - 115 psi

Now I've used the search button and checked out some other compression test results from similar vehicles, and have seen that about 155 is normal, and 128 is as low as is acceptable.

The car runs good, the turbo still spools hard like the day we got it, but... every now and then, when the engine is warm and at idle, some grey smoke pukes out the tail pipe. It doesn't happen for very long, and not very often, but it does happen. With compression test results this low and the occasional smoke, does anyone have any idea what could be happening? Let us know before we just rebuild it. Thanks!

[AmoebAssassin]

Low compression and oil smoke...sounds like worn piston rings.

[Newcastle82]

Is there any way to check the rings without tearing the head off?

[AmoebAssassin]

Do a leakdown test, that's the best way of knowing.

A ghetto way to test would be to put some motor oil in the cylinders through the spark plug hole and immediately do a compression test, see if this raises your numbers. If it does then you have bad rings.

[sean8564]

yeah it is the rings and like he said earlir leakdown is the only sure bet without tearing apart your car