low compression(burnt valve?)

[Yami]

iv got a s14.5 and #1 cylinder is reading low on compression around 70psi to be exact, the car doesnt burn no oil neither does it smoke, i did hav a problem one night where i was over boosing and since thn the car has had this low compression and a slight rough idle, im thinking its a burnt valve, i did try an old trick to check suction by the exhaust which determines a burnt valve and it does have suction, any other ideas yawl got?

[Z U L8R]

unless you were overboosting with low octane gas, timing advanced, and nitrous spraying i REALLY doubt you burnt a valve

you probably cracked a ring land or popped ur headgasket. do you have any other symptoms?

if you want to be certain of where your compression loss is, then you need to do a leakdown test with cylinder 1 at tdc. you'll hear the air rushing out of wherever your cylinder leakage is. you'll hear it coming out of the exhaust if it's the ex valve, intake if it's the intake valve leaking, crankcase if it's the piston, and you'll get bubbles out of the coolant if it's hg.

other than that, check for other symptoms. but since you already know you have low compression, it'd be a good idea to start saving up for another motor, or tear it down and replace the damaged goods. at the end of the day whatever the problem ends up being, you're gonna have to freshen up the motor or replace it.

gl with it, sorry it's ng

Dave

[TheWolf]

Pressurize the cylinder and listen with a mechanics stethoscope... you'll hear it run back into the intake if the intake is leaking.. out in the exhaust manifold if the exhaust is.. or down into the crankcase.