timing belt then blow up????

[redbullgotwings]

i just did a timing belt and head gasket on a 2.8l avant.
it ran before i did this.
i got it all back together today and cleared all the fault codes. none popped back up.
i did a TBA and it went through well and it still idled funny and no throttle response after.
i was holding the gas to the floor and it started to idle better. then there was a loud bang twice and then it just jumped up to red line and then shut off...

any input please help.

[redbullgotwings]

bump i just had someone on the A4 B5 forum say i blew up the motor and i dont see how that couldnt happened. everything was oiled and this happened in under a minute it wasnt hot or anything. ugh please anyones input please.

[Slimjimmn]

cam timing off
valve hit piston
valve broke off
engine locked up

[vdubtech398]

no good

[kfzmeister]

I agree, things do not sound good. I'm currently repairing a 30V V6 that had the timing off a notch and it bent two intake valves (cyl1&4). Those pistons are dished and virtually no clearance.
Good luck.

[bavareze]

so if valves are bent but not broken, replacing the valves will solve the problem?

I mean, the piston looks good in my car, I was wondering if there could be some damage beyond what is visible in such case.

[kfzmeister]

Typically replacing the valves is all it takes, providing pistons are o.k.. You have to have some proper equipment to do the job, like a spring compressor and a timing bar when you put it back together.

[bavareze]

so what exactly makes the difference between bent and broken valves? or is it just a matter of luck?

[tryin2vw]

Luck between bent and broken. In the original TB replacement, was the cam-bar/crank pin used to set the timing? Were the cams and chain tensioner installed properly in both heads? These are items that can cause rough idle when replacing heads.