Timing is mysteriously changing

Hello all....I thought my problems were solved when I got the new IP but there seems to be a lingering issue.

I was able to set everything up TDC and get the timing setup to around 55 a couple of weeks ago. Keep in mind it was cold out and the VAG told me that the engine was not hot enough though the fuel temp was around 130.

Anyway...about a week later I had a hard time starting the car at work. I drove home, about 80Km at a speed of about 120kph (hope there are no cops here). when I got home I set up the vag and it told me that the timing was at about 17. I adjusted the pump to 55 again...tightened everything to spec and all seemed to be fine until the past Tuesday. Another hard start at work...got the car home and again timing was around 15. This time I made sure to check that everything was still tight at 18ft/lb. No problems.

I set the timing again....it was snowing out and vag said engine not warm enough. Fuel temp was around 125. I checked the timing yesterday when I dropped a coworker off and it was around 46 with fuel at 138. This morning I arrive at work and check the timing and I am at 38 with fuel temp around 148.

Yesterday was a warm day and today it is about 50 and raining here in detroit.

I am at a complete loss at this point. What could be the problem? The IP is rebuilt from VW. I have been using GUNK fuel conditioner for the past 2 fill ups. The timimg belt was changed back in January.

If anyone can help I would greatly appreciate it.

thanks

1999 A3 Jetta
340000km

In the articles section there is an excellent writeup on A3 timing belt change. One of the pictures:

http://pics2.tdiclub.com/members/drivbiwire/TDI%20Timing%20Belt%20Pictures/2000_1228_093911AA.JPG

shows a big rusty bolt, and advices: "under no circumstance loosen or use the center nut to hold the crank".

I am certainly no expert in this area, but from what I have read and heard about these engines you may have to loosen this bolt after all. :-(

Hope some real expert will chime in.

W.

There is a chance that the bolt on the crank gear is not holding any more. The bad news is that it ruines the gear and crankshaft and the next thing is it will ping the valves if let go for too long. Happened a lot on the early motors from what I recall.
Steve

And how would I check that? Just use a torque wrench and make sure it is tightened properly???

a REALLY REALLY BIG WRENCH!

These things need like 300 ft lbs with the 1/4 turn.

It is a TTY bolt so replacement is the only way to check it and then the gear and crank can be visually checked. Removal of the belt is also part of this procedure.

Exact same thing happened on my son's 98 Jetta 2 years ago. Crank bolt loosened and ruined the timing belt sprocket located on the crankshaft. New sprocket and bolt torqued correctly and all is well.

So let me understand what is you guys are saying cuz the 300ft/lb comment threw me off.

We are talking about the gear that is at the very top of the whole timing belt setup? The one connected to the camshaft that you lock down at like 33ft/lbs?

Is that correct???

I noticed when I had that off this weekend that it was scored on the inside.

I am no expert but I thought that this was odd and perhaps need some closer inspection.

Is the crankshaft on the bottom of the engine???

Another question I have is if this were happening would I be able to setup the mechanical timing TDC each and every time???

NOT THE CAMSHAFT BOLT at the top of the engine but the crankshaft bolt and pulley at the bottom of the engine. The same one that the other two belts go around also.

PS you could set the timing perfect everytime but it will change as the pulley moves in relationship to the crankshaft. I spent several weeks chasing this problem and even installed a new pump. All for a $2 bolt and a $30 gear.

Don

Tony,

I have mailed you pictures. Don