jayknight

Here's the senario........Big brother me helping little brother with car......pro bono of course cuz thats how family is I guess.....lol

Long story short the tensioner let loose on his 4.2 and the timing belt was slapping around. I have done many timing belts over the years but this motor is awful special when it comes to things......lol.......
First issue was there was damage on the plastic housing for the timing belt where the timing marks line up. So in my infinite wisdom I find compression stroke with a gauge pull the plug on cylinder one and place a dowl in the hole to find tdc. At this point I had no idea where the crank locking pin cover was at and could not find it anywhere after what seemed like 20 hours of searching. So I see some posts about just marking the belt yada yada and think to myself this is not how you do things but I was in a hurry.....
So I go to town releasing tension from the belt with out the crank lock in place because the cams were at a 45 degree angle........mind you this car was running with this orientation with no apparent valve noise just the belt slapping around. Cams went spinning like tops and now I'm in hot water.........I can't get the cams to line up right yada yada so plan b gets formulated........................................ ...................................
Plan b take the valve covers off pull the cams line everything up bada bing done. I have now located the crank locking pin in the tdc marking area it is tight and the crank is not moving at all......So here is the real question how come tdc is not where the cylinder number one is on compression stroke........matter of fact I believe it cylinder 5 which makes it super confusing. Cylinder number 1 is passenger side front piston 5 is drivers side front piston..........so when I go to line everything up is it going to work.........I can't find much on the interwebs about timing this motor from scratch and my manual is worthless un less you have the 6 cylinder

Harleyguy

You need a manual!!!!!! It's almost a guarantee that the motor has jumped time with a loose belt as you describe. If you put things back together wrong and fire it up you will most likely do more damage than the car is worth in running condition. When you do a search on Google for information put as much specific information as possible in the title and it will weed out a lot of the stuff regarding 6 cylinder motors. You will get a ton of information and most likely YouTube videos showing you things. There are also special tools required to do the job. You can sometimes rent what you need. Also get a timing belt kit. It will include all the things that are powered off the belt (water pump, thermostat is behind the belt, idler pulley, and rollers as well as a new belt). You don't want to have to do this again in a few hundred miles cause you were saving a couple of bucks right now. I just recently had mine done at an independent shop and it was over $1600. Probably could have done it myself but would have to buy the special tools. Besides now the work/ repair is guaranteed. It would have cost me around $800 just for the kit and tools. The shop I used works on a lot of Audi's and I got my car back in two days. My car is an'04 with the same motor as you.

jayknight

Thanks for the reply. I do have the manual and all the special tools need to complete the job. I don't think the belt jumped time. I did order the kit got water pump all the pulleys tensioner belt and the shoes for the cam chain tensioners. What my real question is how come tdc is not top dead cylinder on number one with the crank in the locked position.

Harleyguy

Based on what you're saying, I would say it is 180 out of time. You said the belt was slapping the cover hard enough to damage it. That would be more than enough to walk things out of time.
1. Try turning the crank one revolution while checking compression on number one. If compression comes up, there you are. It was 180 out.
2. Get the crank to TDC and lock the crank. If you're replacing the cam chain tensioners then with the motor right you can line up the cams correctly. Can't be off even a little.
3. Change the thermostat while you are in there. It is behind the belt and is a common failure item. You will be back in this deep again if the thermostat fails in a few miles. Only about $10 or $12.
4. Once you have the belt back on, manually rotate the motor 8 or 10 full revolutions checking all the alignment marks at every revolution and when finished. If there is any valve to piston contact you should be able to hear it when turning the motor by hand. They should line up after doing this. There are a couple of threads on this in the forum that may explain it better. Basically you don't want it to turn under power til you are absolutely sure.
I'm sure you will get it, just gotta be patient with these engineering nightmares!

4Driver4

TDC isn't really TDC to Audi. If you have the belt off and the pin installed, hopefully the cams are close enough where you can get the bar on. If not, remove the pin, turn the engine about 15 degrees, turn cams home and lock them in with the tool, then return crank to the point where the pin goes in.

jayknight

Thanks for that I wish I would have thought it through more but I have removed the cams which was good I found a cracked tentioner shoe in the process. I'm off tomorrow so we will see how it goes I should do a r&r on this because the info is slim on resetting the timing from scratch. I have found that on the 4.2 the tdc timing is based on cylinder 5 which answers my question.

Narlift

Ofcourse he never posts back haha. could have used his help/notes. oh well

Harleyguy

Check some other posts. There's a ton of info available.