psi

[holmes]

out of curiosity what psi should each cyclinder have on a 1.8 8v carb engine not sure of the engine code as iam at work and cant see. i checked mine and from what i remember 1 was 10.5, 11, 11.5, 12.5 ish does that sound right?

[Chris S]

Your motor code is GU,

My VW manual says that with a new a GU, 1P or PF motor the compression should be between 10 & 13 bar, the minimum pressure for a used motor is 7.5 bar, with a maximum difference of 3 bar between the cylinders

For the GX & RP motors the figures should be new between 9 & 12 bar, the minimum pressure for a used motor is 7 bar, with a maximum difference of 3 bar between the cylinders

[no such user]

Sounds right for a motor with a fair few miles on it, cr to miles seem to go a bit like this

6-7 bar = ( mega miles + abuse ) it’s dead on it’s feet gonna drink fuel and make no power and be a sod to start
8-9 bar = (150,000 + miles) it’s done lots of work and would like it’s valves regrinding
10- 11 = (100 – 150 ,0000 miles ) resonably healthy.
12- 13 = ( sub 100,000 miles ) very healthy.

[holmes]

thanks for the info guys do you have the same info for a 2e engine?

[Chris S]

As the compression ratio is the same as the GU/1P/PF motor at 10 to 1, then the compression pressure will also be the same

[no such user]

it’s a general trend and applys to most N/A petrols

[Author]

Posts