I have MY01 with 42k on the clock. And I did a compression test new tester pulled fuel fuse and cranked 8 times with gas pedel down. here were results...

cyl1...200psi
cyl2...205psi
cyl3...200psi
cyl4...200psi

thing is I haven't owned car long and the tranny is out of an 03 but the sticker on motor says it's an 01 but with only 42k on odo. why is it that low isn't it supposed to be 240psi or in that range? Is my motor done? thanks guys

 

the numbers are all close and thats the important thing. Your tester could be out a bit.

 

a leak down tester will tell you where its leaking. either rings or valves.

 

Many over on BITOG are having great success restoring compression using Auto-Rx. It's easy and safe to use...just works as you drive.It won't fix anything mechanically wrong with your car, but will thoroughly clean your engine, seals and ring packs.

http://www.bobistheoilguy.com/forums/ubbth...3909#Post293909

 

There is a lot of variation among compression testing units, so low numbers on their own isn't a big concern. Those numbers are very consistent, so that's good. Is there a symptom that you are concerned about?

 

did you do the test on a cold or a hot engine? this will effect results.

always do it on a hot engine. (well warm)

 

no I had just got done driving on freeway so engine was hot.. I was concerned because I plan on adding boost to the mix and want to keep power up, and not add boost to a tired engine and end up causing lots of damage. leakdown test is just putting some oil in cyl and testing it then isnt' it?

 

Adding oil is part of a "wet" compression and leakdown test. A leakdown test requires the use of special gauges and a source of compressed air. It's helpful in pinpointing the cause of power loss, be it intake or exhaust valves, or the piston rings. I had a motor that yielded very good compression numbers, but that had horrible leakdown and was about 15% down on power compared to a fresh engine. I don't know if the reverse is true (low compression with good leakdown), so it would be informative to run the test on your engine before force-inducting it. IMO, leakdown results are more relavent to your choice to force-induct than a compression test.

 

you can also put a drop of oil ito each cylinder and then repect the compression test to see what numbers you get then. If for some reason you get much higher number, it would show that you have ring wear.

 

i dont have a leakdown tester, but I will try the oil wet test idea when I get off work.