C63AMG

Physics doesn't care personal opinion.

lpcome

Yes I did understand that... So I did the compression test after I drove around and made sure the engine was hot.

lpcome

I'll make an arrangement for leak down test with a shop close to my work place. Will update any progress when that's done.

Thanks to all your advice!

myflys2k

Make sure the shop diagnosis where the leak is coming from. Weather it's the intake/exhaust valves or piston rings.

starchland

Your right it doesn't but there may be an issue that would only show up when the car is hot, it is possible wouldn't you agree?

Could be something as simple as a bad valve adjustment

C63AMG

Your right it doesn't but there may be an issue that would only show up when the car is hot, it is possible wouldn't you agree?

Could be something as simple as a bad valve adjustment
[/quote]
Not when you're just checking for a difference in compression between cylinders. Otherwise, yes, operating temp is ideal (ie in the case where they all seem abnormally low).

Compression % difference is based on a control. As long as you do them all within a cretin timeline hot/cold doesn't matter (ie don't check one cold then the other 3 hot etc).

starchland

Pull the VC and check the valves

lpcome

What is a VC by the way?

Before taking it to a shop, I plan to do another dry/wet compression test on cylinder 1. So that at least I can have some clue of the appromix leak... Valve or rings.

If the wet test has higher PSI number then it means leak from the rings, isn't it?

starchland

Likely. VC=valve cover
Is the car burning oil, smoking,etc?

C63AMG

This was one of my Cyl 1 ex valves after 190k. Too much pitting to machine. Cold compression was mid 220psi on Cyl 2-4 and high 180psi on Cyl 1.



Block, slight scoring in Cyl 1 but within Honda's spec.