Compression Results - Questions
 

I have the compression test results from a Euro Spec '86 Carrera back, and have some questions. The results are 180, 180, 180, 175, 200, 200. As a Euro spec car, with about 50K miles, the 200 are OK. What concerns me is that 175 is outside the normal 10% rule..... I really do not want to get into engine work, especially with such low mileage.

What are your thoughts?

a small difference between compression numbers can be a large difference if you do a leakdown test. if you get a high leakage result on any cylinder, put the plugs back in and run the engine again to blow out any potential carbon bits from between the valve and seat, and re-do the leak test. 4% is pretty damn good. over 10% kind of makes you wonder. 20% and more, something's definitely not sealing well.

Just ran the compressions on my 85 3.2 motor. Every one was between 160 and 165 and the motor has 93k on it.

While your readings are within a small percentage, the closer the readings are, the better condition the motor is inside and smoother the motor will run.

JoeA

How does your motor run? Does it burn oil? If not and it runs good, I would drive it

John, thanks for the reply. It was a PPI and I did not get the leak down done. Blown, it does not blow smoke on start up, but I do not know how much oil it burns (miles/qt).

What was the condition of the spark plugs when they were pulled out? Any of them carbonized or otherwise?

John

John, the plugs looked OK.