First time changing a timing belt on a '99 TDI bug questions

Post by **Fatmobile** » Tue Jan 27, 2009 10:29 pm

We have an auto repair shop in our small town and the guy has a '99 beetle that broke the timing belt.
I helped him pull the head today and the damage looked minimal.

What should get changed along with the timing belt and tensioner?
We figure the waterpump is a pain to change later (like the 1.6 with AC). So we plan to change that.

What block would that be?

There is a butterfly in the intake,... I think it's in the MAF(?), it has a plastic vacuum canister that moves the butterfly.
He broke the barb on it, what's it called?,... so we can get another one.

His intake was all carboned up, how is that cleaned? Can he use chemicals or does it need to be sandblasted out?

caveman · Post by **caveman** » Fri Jan 30, 2009 10:39 am

Make sure that damage is minimal, you don't him to drop a valve that was bent after everything is back together.
Yes change the water pump while you are there.
It should be ALH engine code.
That unit with the butterfly has 2 functions. The actual butterfly is to make sure the motor shuts down when the ignition is turned off [ so it doesn't "diesel"] . On the bottom is the egr inlet.
To clean the intake if you have time i would soak it in a parts cleaning machine for a couple of days if you have that luxury, otherwise there are cleaners available to degunk it.

Post by **Fatmobile** » Sat Jan 31, 2009 12:16 am

He says he has some chemical carb remover so we'll try that first.
What is that plastic vacuum motor thing called so we can look for a new one.
He said the beatle was running good, I bet it runs much better when all that carbon is removed.
I talked to him today. Quite a bit of oil in the intercooler.

It looks like there is an intermediate shaft sprocket that runs off the toothed side of the belt.
It seems to turn hard by hand (but the sprocket is small and hard to get torque on). What all does that run?
The belt didn't actually break, the teeth were stripped off of it. He was thinking the I-shaft froze up, he couldn't get it to move, until he went to show me it was froze, then it moved, using a screwdriver to turn it.
Is that an external oil pump sitting on the front of the block, with the oil filter on it?
The latest Bentley I have goes to early '99 and doesn't cover this block. I think he has been reading something more up-to-date.
He is taking the head in to get pulled apart and rebuilt. The exhaust valves were the only ones to leave marks on the pistons,.. and the marks weren't very deep.

MayorDJQ · Post by **MayorDJQ** » Sun Feb 01, 2009 10:05 am

Do yourself and you're customer a favor and get a Bentley repair manual. Do you have the proper and necessary tools for changing a tdi timing belt? the mark & pray method is a really bad idea on these cars.

Change the water pump, all 3 rollers, and the tensioner. Complete kits are available from several online vendors.

there's no external oil pump. What you're looking at is the canister that houses the oil filter cartridge.

Post by **Fatmobile** » Mon Feb 02, 2009 1:37 am

It's not a customer.
It belongs to the guy at the local auto repair shop.
He said he was reading about it, not sure which manual he has but it's his car and we're working on it in his shop,...
so he gets to buy the manual this time

I was checking out some of the timing belt kits.
They run about $350 and include stretch bolts for the pullys, a waterpump etc.

Way more spendy than a 1.6.

Quantum TD · Post by **Quantum TD** » Mon Feb 02, 2009 1:05 pm

Fatmobile wrote: I was checking out some of the timing belt kits.
They run about $350 and include stretch bolts for the pullys, a waterpump etc.

Way more spendy than a 1.6.

Indeed, but alot more power stock, and more power thru all rpms with the VNT.

It should also be noted that, even after changing the belt, he'll have to set the pump static timing. In order to do so, he'll need a VAGCOM, or similar computer hookup. The VAGCOM is nice because of the timing graph which makes it mindles. Either way, setting the timing on a TDI rotary pump is a bit of a PITA. You have to move the gear slightly until you get it into range. This means incrementally sliding the gear and then starting the car to check the timing: Fun.

Post by **Fatmobile** » Mon Feb 02, 2009 9:11 pm

Thanks for the info.
I'll see if he has a VAGCOM,.. I got to check out his new bore-o-scope last time I was there.
TDIs don't handle high RPMs like the shorter stroked 1.6s do they?

Post by **Fatmobile** » Sun Mar 01, 2009 2:40 am

The tensioner is way different than the ones on the 1.6.
Self tensioning?
How do we set the timing belt tension?

Quantum TD · Post by **Quantum TD** » Sun Mar 01, 2009 12:43 pm

Fatmobile wrote:The tensioner is way different than the ones on the 1.6.
Self tensioning?
How do we set the timing belt tension?

There should be a notch and a pointer on the tensioner. On the backside of the tensioner, there should be a tab that fits into a recess in the head. With the belt installed over all the pulleys (crank, water pump, cam and IP), the rollers installed (there should be 3 in all), the camshaft locked at the vacuum pump end, and both the IP and camshaft sprockets loose, you turn the tensioner until the pointer on the outer ring, lines up with the notch in the center ring. If you go beyond the alignment point, you'll need to slacken the tensioner and start all over.

In all, it's just like the Rabbit in theory, they just make it idiot-proof by putting the pointer and tab on it.

Here's a link with the pic:

http://vwdiesel.net/phpBB/viewtopic.php ... =tensioner

and another link with the entire procedure:

http://pics.tdiclub.com/pdf/a4timingbelt.pdf

Good luck.