Rough idle and differing opinions by jaguar mechanics

[davidsxj6 (David)]

@Nick_XJ6

That is to say all cylinders were 150 psi with the dry compression test and 180 psi with the wet compression test. The engine was at operating temperature and throttle was open during the tests.

@Foggyoo That should be taken care of, no? Neither low nor uneven.
Comparing his values to my 9:1 engine he’s doing okay I think. See

Does this engine sound about right?

[image] Not to brag, but… this is my (9:1) engine. Pressures are in bar, you don’t want more than I think 10% difference between cylinders. MartinScherz has one cylinder that’s significantly low and the engine still runs fine. Yours is not exactly good but it might well be your valve clearances? Either way work will need to be done. But then you have a good engine and know it! Oh. The motometer tester is great. Did you test with engine hot or cold, did you open the throttle fully while cran…