My engine compression on is fine from 1-3 and the 4th is very low. The 4th one shows 30 psi and 60psi with wet test. This test wasn't done with throttle fully opened. The first 3 was around 135psi. My engine is idling very quiet that's the good part. Should I be worried? Should I use restore engine treatment? I have about 132k miles, there's no knocking or anything. My coolant is green(no rusty color)
Oh and my cel only shows p0440. That's the evap code but the least of my worries.
My distributor inner seal is about to go soon, I've changed the o-ring but still wiped off little oil at the bottom of the cap. Can the seal cause low compression? Idk
Hmm, Ran into a similar problem although I had/have zero compression in cylinders 2,3. Had to remove the head and found that both intake valves are bent.
Performed a quick leakdown test to find out exactly what the culprit was. Car sat for a very long time so I attributed the bent valves to a lack of lubrication or crud buildup on valve stems allowing the pistons to get acquainted with the valves.
If you don't have access to a leakdown test kit, I've found that a 1" pvc conduit fits nicely over the spark plug guide tube'. Place the engine at tdc on cylinder 4 by removing the passenger wheel/covering and placing a 27mm socket on the flywheel nut? You would probably also have to remove your dist. cap to note when cylinder 4 is at tdc.
(Funny part) Blow in the conduit once the cylinder is at tdc, note where the escape of air is coming from. If it is the exhaust then your exhast valves are bent/chipped/damaged, if the air is escaping from the intake manifold then your intake valves are bent/chipped/damaged. If your coolant is showing bubbles when blowing then your head gasket may have failed.
Just a few things to consider... Having taken the head off, I cant see how a leaky dist cap seal could cause a loss in compression. I'd be leaning more towards your valves. Perform a leakdown test and you will know exactly.
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