Just made an compressiontest at my ferraridealer on my 355 and they said the test was ok. How do you read it? On my test i have around 13,5 bars on zylinder 5-8 and 12-12,5 bars on zylinder 1-4
If you want to troubleshoot valve guides, you need a leakdown test. Compression test is usually ok if all cylinders are within 10-15% of each other. If you take a high of 13.5 bar and low of 12 bar, that's about an 11% spread. If you were looking at over 15%, the next step would be a leakdown to see how bad the leakage is and where it is coming from. How many miles on the car?
