Compression test results

[DropSomeMoney]

So I have oil on the front of my engine. So I decide to do a compression test. I've had this car less then a week. So I hope it's nothing major. It leaks a couple drops after I'm done running it. It only drips about two drops after this. So I don't believe the oil is new.

Cylinder 1: 180psi
Cylinder 2: 182psi
Cylinder 3: 150psi
Cylinder 4: 180psi

Any suggestions? Do I have a worn ring?

 

[1995silvergst]

I would say there is a definate problem there not being within 15% of the others. That being said you should also do a leakdown test to eliminate other possibilitys such as bent valve, seals and so on. If the oil on the outside of the engine is what you are refering to change the valve cover gasket if you havent already.

You could also add a little oil throught the spark plug hole and perform the compression test again on 3 to see if the number changes. If it goes up most likely not a valve issue, if it doesnt change your not getting good seal at the valves. This is not as accurate as a leakdown but does indicate.

 

[DropSomeMoney]

Ok. I put a little oil down the #3 plug hole and did the compression test again. It did rise up in compression. Does this mean I have a bad cylinder ring or just a little wear? Or maybe something else? Thanks for your help!

 

[BogusSVO]

Well, it is something not to bad if the oil made a seal.

Run a leak down test now.

 

[uummm]

What was the number on cylinder 3 after you put oil in it?

 

[DropSomeMoney]

I put a lil to much oil down into it so it came back at 200. I'm also not sure how to conduct a leak down test so I'll research it and perform one and repost when I have finished. Thanks for the help again.

 

[onyxtyson]

With the compression raising like it did. I would guess the rings are a little worn.
If you did that compression test on a cold motor then those numbers aren't to to bad. That 150 seems to be just a little wear on the ring but with a warm motor and some oil pressure that ring should seal up and your number might be a little closer to one another. If this is a race engine then I wouldnt like those numbers but in a daily driver Those numbers would be good enough for me.

 

[Kruger]

I have a buddy that has been running his car for over a year with the compression at 130 on one cylinder. - hes making 350awhp +

Dont stress about it too much. (also try another compression tester, I had different reading on a couple before)

Do the leakdown and post up the numbers. Im interested to see how this goes for you.

 

[1995-tsi-awd]

I just bought my 95 about a month ago and the compression was 170-180 across the board. Does this mean it was rebuilt with 136k miles? must be right?

 

[boost97gst]

If you had that high compression then yes, most likely it was rebuilt. Thats assuming stock CR 2g pistons however.