compresion problem

[h***pog]

hi all iv got a problem with my gti r when i start it up and leave it to run for 15mins it wont smoke.then if i drive it hard it smoke very bad and wont stop smoking.i did a compresion test and got ---1st/120 2nd/145 3rd/150 4th/150.

 

[Fast Guy]

It might be a ring land gone. If you do the test again and the results are the same, then realy it's rebuild time as you're outside factory tolerances with that 25-30psi drop between cyl1 and the others.

(It's possibly worth checking the valve clearances before that as that could affect the compression.)

 

[h***pog]

how can i check the valve clearances??i just had some pisions put in could it be that??:? :?

 

[Fast Guy]

Only if the pistons were fitted straight into old worn bores. OR......... say the old pistons were killed with detonation and the pistons were replaced with no fixing of the cause of the initial det.

Not sure how much work was done, but the bores should have been checked for condition and if need be, over bored for bigger pistons.

Who replaced them?