No compression. HG? TB? Piston?

[j30-tsi-awd]

so...good news
after i got all my new stuff put in
evo turbo and 650 safc all that stuff..
i was driving it and scoootin around and i was in 2nd and about to shift into third at about 6800 and i noticed my tach stopped and my car stalled... and so i coasted 4 a bit then pulled over.
there was oil all over....inside the engine bay.. so i babyed it to the shop where i workd and checked everything over i ran a compression test and they were all 125 ish except for the 3rd cyl which was 0 so either the head gaskets gone right in that spot or i blew the piston right? im kinda not sure. i know i need to pull the head next.
but does anyone have any other suggestions for me? its a jasper motor so it should b under a warenty but i dont know if its covered being modified?
so any help would be awesome!

- scott

 

[Duke901]

Do a leak down test also. You might have slipped the belt and bent the valves in that cylinder.

 

[j30-tsi-awd]

hmmm alright. i will do that. the belt was still very tight. with no rips or cracks on it.
any other ideas??

- scott

 

[oldman]

Did you check timing marks? 0 compression almost always means bent valves, perhaps the BS belt broke and caused your timing belt to slip.

 

[Defiant]

Do a leak down test also. You might have slipped the belt and bent the valves in that cylinder.

Valves will virtually never bend in one cylinder, and if timing's jumped, the motor won't be driving to the shop for a check-out.

We're sorry, but you do not win this lovely dinette set chosen especially for you.

 

[j30-tsi-awd]

ill check the marks this weekend. any other ideas? anyone else been in this spot?

 

[brandonzero0]

it could be a leak, IE bad valve seats, piston tings, head gasket, and other things,

 

[brandonzero0]

do a cylinder leak down test is your best bet to see where you are.

 

[Old Mitsu Tech]

If you lost it on one cylinder, then you could have a holed piston or you could have taken a chunk out of a valve. I've seen both. I would find a mechanic with one of those little bore scopes to look down the cylinder to verify before you pull. You are likely going to have to pull the head anyway.

Good Luck

 

[j30-tsi-awd]

alright. very helpful thank you.
does anyone else have any imput?

 

[j30-tsi-awd]

i pulled the valve cover off. all tops of the valves and springs look normal and have no play on them. the belt is tight with no signs of slippage. so im guessin that it hsnt jumped time.

 

[j30-tsi-awd]

well after finally after months of scrounging for cash. i got it fixed up.
it was the 3rd cyl it leaned out. so it was gone.
thats the update. thanks for the help.
Scott