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speedy13
April 22nd, 2005, 03:49 PM
So as some of you may know I'm new to sact town and sac town dsm.I am also new to the turbo world since my last car was na dsm.okstopaughing,thats not funny.Well anyways I recently purchased a 90' tsi awd.so today i finaly got around to checking some vitals after i replaced both cv shafts.Took out the intake pipe and checked the turbo for play and, zero play,up down front back,side to side ,nilch.Ok,good thing.So next I check my compresion,I get the following:
CYLINDER 1 = 130
CYLINDER 2 = 125
CYLINDER 3 = 125
CYLINDER 4 = 120

Are these good numbers?They seem a little low to me but the engine pulls really hard.according to the previous owner the engine was rebuilt 40k ago.The odometer reads 167k now.I did loose 1qt of oil before,but it hasn't done it anymore.there are absolutly no leaks.spark plug seals and valve cover gaskets are tip top.Timnig belt seems new,but it seemed like it was rubbing up against the cover for a while.So are these good numbers or do i have to start saving up for a rebuild soon?

ZenkaiRacerDsM
April 22nd, 2005, 05:20 PM
That seems really low. Like servicable limit low. Did you do the test while the engine was warm? If so I would try it again adding oil the chambers and see if it rises. If so your rings are tired.

EuroEclipse
April 22nd, 2005, 06:19 PM
also, what kind of pistons are in there? if they are low compression pistons, then that changes things also.

speedy13
April 22nd, 2005, 06:26 PM
yes the car was warm,i was thinking the same thing as well.As far as i know,it's the stockpistons 7.8:1

peregrine
April 22nd, 2005, 07:20 PM
did you pull the injector fuse? did you floor the gas pedal while cranking?

speedy13
April 23rd, 2005, 09:35 AM
oh shit I'm a fuckin idiot,I didn't tell my wife to floor the gas pedal!!lmao.Why do I need to pull the injector fuse?,so The injectors don't throw fuel intt the mix?New numbers will be up next weekend,with my new revised compression numbers.

peregrine
April 23rd, 2005, 09:46 AM
oh s%!t I'm a fuckin idiot,I didn't tell my wife to floor the gas pedal!!lmao.Why do I need to pull the injector fuse?,so The injectors don't throw fuel intt the mix?New numbers will be up next weekend,with my new revised compression numbers.good luck :D

my3awds
April 23rd, 2005, 09:58 AM
CYLINDER 1 = 130
CYLINDER 2 = 125
CYLINDER 3 = 125
CYLINDER 4 = 120

Make sure you run your car around so when you do a compression test, your motor is "hot". Do as John says, pull the "MPI" fuse, have someone floor the gas pedal while doing the whole test, then crank 10 revolutions or until your needle on the gauge stops increasing. Release the gas pedal, move to the next cylinder :). Those number sets aren't that bad considering its a 1g (150 is perfect). Service limit I think is 121 on a 1G and has to be 10-15psi difference between each cylinder. Keep us posted :)

Manny

speedy13
April 25th, 2005, 05:24 PM
Ok with th car in operating temp,at wot,my new and revised compression numbers are:
CYLINDER 1 = 130
CYLINDER 2 = 135
CYLINDER 3 = 130
CYLINDER 4 = 125
OK there they are now tell me what you guys think.

93T4L0N
April 25th, 2005, 07:07 PM
They still look pretty low. :cry: Id say its just tired. Good luck.

peregrine
April 25th, 2005, 07:52 PM
i think your fine. theyre all within 5 psi of each other. boost away until the motor goes. then rebuild it.

my3awds
April 26th, 2005, 07:07 AM
Yup looks ok to me. Should last a good while if you take care of her. Get that 16g already :)

Manny