Audi0s

ok well i didnt torque my head down to the right specs, but in the right sequence...so it wont always run when cold, real tough starting, they compression tested it, and the loss of compression jumps around, like sometimes itll have none, but then itll come back, so they think that the heads warped,but im not leaking coolant. my next best guess is that a vlave isnt seating correctly, so when it warms it runs ok..any help?

AntiSocial

Remove head, have it machined at a different shop and have them look at the valve job.

xr4tic

It doesn't make sense that the compression jumps around. Have you done a leakdown test?

201-A4

Did you use a new head gasket?

Mat Indukts Lambos

We torqued the head bolts correctly, and all was ok. We knew however, that the car had only been warmed up & driven a couple times, not more than a couple miles total. It also had a problem keeping coolant in, though. Plus, if you've been driving it, you may have warped something due to the un-torqued head bolts.

Depending on your situation, just torquing the head bolts correctly may solve your problem.

If you had the head ported & polished, it may be that you need a valve seat job. Certain places don't mention that you'll need it, & just take it for granted that you should understand & know that. Valve seats can cause sporadic compression concerns depending on engine temps, yes.

201-A4

opps meant to post this unser the main thread.