[Mk2] [Turbo] Compression test results

[garry goodall]

Just done a compression test on my rev 3 turbo and I have 120psi across all four cylinders ! Does this seem abit low or does it only matter when there is a difference across the cylinders ?

Cheers

[Slarty]

Well, an indifference will point to a suspect cylinder/cylinders but yours do seem to be low across the board..

Did you have the throttle wide open? If so, it might be worth putting a few drops of oil into each cylinder in turn and repeating the test. It'll show up if you have worn rings/bores as the pressures will go up after the oil seals the bores.

[garry goodall]

No I didn't do it with throttle wide open, redone with with throttle wide open and got 150 across all four ? What would this suggest then? Should I do it with throttle wide open and oil in see If that makes a difference

[garry goodall]

Just put oil in cylinders and it's 150 across all four regardless of throttle open or not ?

[Super_red]

What an engine scores on a compression test is largely irrelevent, its the difference between the numbers that tell the story. All 4 the same is spot on and better than I have ever seen.

[garry goodall]

Workshop manual says min comp is 128 psi how come compression goes up with throttle open ?

[Chris]

Workshop manual says min comp is 128 psi how come compression goes up with throttle open ?

Air can get in to the cylinders.

[greeny]

Did you do it with the engine warm?

150 across all 4 pots is fine though.

[garry goodall]

yeah did it with engine at operating temp