Quote:
Originally Posted by white_335i
I am curious why you say that putting some oil in the cylinders doesn't help? Fuel tends to wash away the oil that is on the cylinder walls and sometimes doesn't help seal the rings. I've ran into this issue with my car, but like I said curious to know your thoughts.
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that's not how it works. compression tests are to be performed with the fuel and ignition disabled. so if you're washing away your cylinder with fuel when doing this test first of all you're doing it wrong.
because the troubleshooting process for adding oil into the cylinder only makes sense if you first register a 150 psi and you can determine that your rings are clogged / worn out if you see an improvement of 190psi. minimum pressure for fuel ignition is 140psi. it's basically an indicator if you should plan for an engine rebuild or try to add an oil additive like MMO or autorx and check again compression at the next oil change to track for improvement.
when there's 30psi in a cylinder oil added is not going to tell you anything useful.
