cjhboise

I had my timing chain rebuild service done at 73,000 mikes by local Audi independent . Last week at 84,000 miles a bolt on one of the tensioners for the chain broke, all hell broke loose. Pulled over asap was going 75 mph when it broke. I have always changed oil and done all service before it was needed and been meticulous on service. It was suggested by a 20+ year Mercedes mechanic who worked on Audis for over 15 years before his shop stopped working on Audis that the bolt may have been over torked during the timing belt service causing the failure. Thoughts? Thanks!

jhuffman

Are you positive that it was the bolt that broke? If it was over torqued I would think that it would have happened sooner than that. Could be that the belt was faulty or that the tensioner itself failed. What exactly happened (anything out of your ordinary driving I should say)? Or could the belt have been installed incorrectly?

cjhboise

I haven't inspected it yet, car was towed to the shop and I spoke to the mechanic who told me that the bolt on the tensioner broke. I wanted to do a little research before I bring up the subject of the possibility that the repair was done incorrectly. The car was being driven the same as always, I have owned it for 6 years and did the timing chain service early to avoid any problem. I planed to keep the car for a long time. I have had all of the service after the warranty expired done by this shop. It the only Audi repair shop aside for the dealer and they have always done a good job.

HWY HNTR

any updates?

cjhboise

Left the car with my local independent who worked on it in between other work so it took a while. All the valves were bent and pistons damaged as well as the head. The mechanic replaced all the vales redid the head and rebuilt the whole top end of the motor. He had a way of doing this with out pulling the motor or transmission. We inspected the turbos and they were fine so we left them alone. Every thing damaged or worn was replaced and I got the car back in December and have been driving it since. It runs great and I have put over 5,000 miles on it since getting it back. Happy I fixed it.

Peter Badore

Maybe the shop that did your chain rebuild service didn't use the Audi special tool to compress the tensioners and used an improvised technique to compress the tensioner/adjusters during reassembly. Possibly this over stressed the attaching screws (these are small diameter screws 6mm if I remember correctly) as they were used to compress the tensioner/adjuster assembly.