thanx KJ and jimmy hat...............

 

if you put oil in the cyl you are checking for ring seal. if compression stays the same after adding oil, the rings are not the problem. adding oil to the cyl takes up any air gaps in the rings and give a better seal. adding oil will tell you nothing about valve condition.

 

no what I ment was if you test with the oil in the cylinder and you get the same compression that means that the valves are screwed and the compression is leaking out through the valves. know what im talking about?the oil is still there?

 

THe best way to find out where they are leaking and where you are losing compression from after doing a compression test is by doing a leakdown test on the suspect cylinder.

once you do the leak down test and air is being blown into the cylinder (which is at TDC firing stroke) you can then turn the air pressure up and listen.

Open the oil cap. Do you hear any air (kind of sounds like putting your ear in a big shell, the seaside noise)

Unplug a vacuum line. Do you hear any air (sounds like a minute air leak coming out)

Listen out the tail pipe. Is there any noise? (sounds like a very deep air tone)

Depending on where the air is escaping, you will then know where you are losing compression from. If it's coming out the oil cap, you know your rings are the problem. If it's coming out the vacuum hose, you know your intake valves are leaking. And likewise, if you hear it coming out the exhaust you know you have a problem with your exhaust valves.

We can perform a leak down test for you here at Secret Services, as well as do this diagnosis to help you find the problems with your car, and thus work towards making your car 100% once again.


Mattback