does this make ANY sense?!?

93-Katt-TSi-AWD · Apr 6, 2004

car ran like crap so I tested the compression (6-bolt 90 TSi AWD)... it was around 150-160 on the first three cylinders but only 70 on the 4th!!! The block and head were both rebuilt... I checked the timing belt and the crank mark was about 2 inches away from the BTDC mark!!!! how could it only bend the valves in one cylinder??? is that even possible??? let me know what you think
Thanks,
Dave

crankbender · Apr 6, 2004

Because of the harmonics of the motor and cam snap over you may only bend 1 set of valves.

Defiant · Apr 7, 2004

Hm. I'm not sure I buy that one.

crankbender · Apr 7, 2004

Very unlikely but possible.....

I probably should have added more at the time (dead tired right now and typing up notes for my freakin test in the morning).

The more likely problem is that you killed that piston. Are you sure the valves are bent? Usually bent valves give a seal less than 70.

Tallen · Apr 7, 2004

Was the car warm? Did you pour a capful of oil into the cylinder then check it from there? That will give you a good idea of whats messed up.

93-Katt-TSi-AWD · Apr 7, 2004

it's 70 wet and about 60 dry

fivestardsm · Apr 7, 2004

It is possible that you have a stretched rod, I had it happen on my 90 tsi. It did the same thing, You'll have to do a leak down test.

Steve. :talon:

93-Katt-TSi-AWD · Apr 9, 2004

what's a leak down test?
Also, would the stretced rod truly be caused by the timing being off? that's the reason why I think it's a set of bent valves.....

crankbender · Apr 9, 2004

pull the valve cover and see if the valves are bent. As said before usually when the valves bend the compression goes to 0.

Take a look through the spark plug hole with the piston down and see if you can find any pits/bits of shiny stuff down there...

fivestardsm · Apr 9, 2004

http://www.dsmgrrrl.com/FAQs/leakdown.htm

Check this link out. It should help. Also don't be afraid to do a search for the topic that your interested in, it is a 99% guarantee that most problems that you will experience have been addressed before and again.

Steve.
:talon:

The Central Hub for DSM Community and Information

does this make ANY sense?!?

93-Katt-TSi-AWD

crankbender

Defiant

crankbender

Tallen

93-Katt-TSi-AWD

fivestardsm

93-Katt-TSi-AWD

crankbender

fivestardsm

Similar threads

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds