[Mk2] [Turbo] Rev 3 static compression test results?

[yokomomr4bx]

Hi guys,

Been having some long term niggling troubles with my rev3 and wanted to rule out compression issues. Ran a static test on all 4 this morning (stone cold engine) and came up with 120+/- 1 or 2 psi across all 4. Quick google search would have me believe that this is on the low side of normal and touching on a possible cam belt slip?

Wondered what opinions we had on these numbers? I will run a hot test after a little run this afternoon and see if the pressure are any different, but I can't see them rising that dramatically?

Thanks, Ed

[SonicSW20]

Do a hot test with the throttle wide open. You may be surprised.

[yokomomr4bx]

That’s the kind of confidence I need

Just checked the timing and general belt condition as it has been about 40,000km since I did it, still spot on.

I’ll see what the hot test returns, good shout on the throttle, forgot that!!

[yokomomr4bx]

So with hot engine and open throttle I've got 150psi across all cylinders, all good?

[SonicSW20]

If its oretty even across all four then 150psi would not concern me. Mine makes around 180 but there's so many variables on the day. As long as its close across all of them and it's not silly low, you're good.

[yokomomr4bx]

Thanks Gazza. They were all within a few psi of each other. I may run a leak down over the coming weeks to completely settle my thoughts on this!

[SonicSW20]

Yep, that's what really matters. You can pretty quickly confirm the mechanical timing is correct by taking the top cover off and turning the engine to TDC and check against the marks on the cover for your own piece of mind.

What is the issue you're having?

[yokomomr4bx]

http://www.imoc.co.uk/forums/viewtopic.php?t=193669

Still facing the extremely intermittent (like, every 3 weeks intermittent) cutting out when I move off from a standstill after a prolonged period of sustained RPM, approx 20 miles at roughly the same RPM.

And yet I did a 180 mile trip mid week with this kind of driving and it had no problem... go figure!

Definitely the toughest diagnostic issue I've ever encountered in and out of work.