Volkswagen Repair: 1.8 Jetta valve timing, tdc mark, timing belts

Question
Hello, Rocky
My daughter's 02 Jetta  died while she was driving it. After getting it towed home, inspection revealed that some teeth were missing from the timing belt. Is there any way to check for head damage without pulling the head? I will replace the belt this week and do compression testing. Also, what is the easiest way to set the valve timing to tdc? The Chiltons I have says to align the mark on the cam drive gear with the tdc mark on the rear timing cover, but her car has no rear cover and I can find no marks on the head. It is a 1.8 gas turbo.

Thanks for a great service.

Answer
If you have access to "shop air," ie. a compressor that can operate at about 100 psi, you'll need to do a leakdown test to determine if any of the valves were bent during the catastrophic timing belt failure.  At the left(drivers' side) of the engine, there is an access hole with a rubber plug in it on manual transmission cars, if it's an automatic there's a rectangular slot with no cover.  Use a flashlight, and look for a little, tiny circle with a line through it on the flexplate(auto), or the flywheel(manual), and line it up with the pointer that is cast into the cylinder block.  This is TDC.  But it might not be TDC for number 1, it might be TDC for number 4.  On the right side of the engine, the passenger side of it there is a black plastic cover over the timing belt that you have already removed to see the missing teeth.  Behind the cam gear, and probably covered with dust(black sticky rubber dust, from the timing belt) there is another black plastic piece that's bolted to the valve cover.  Wipe it off, and you should see a pointer, or arrow molded into the plastic cover.  Line up the pointer on the rear cover with the line that is cast, or machined into the cam gear.  Once that's done re-check the slot, or hole at the left side again, to make sure the crankshaft is still in place.  These engines are no picnic to change timing belts on.  The water pump should be replaced, and the tensioner should be replaced all at the same time.  When you get ready to install the belt, be prepared to use muscles in your fingers you haven't used before...ever!  They are tight!  And be careful, because you can be a tooth off, and not know it until the check engine light comes on after initial startup.  The quotation from the chiltons book is probably referring to the cover at the back of the cam gear, and the pointer that's covered with goo.  There are no marks on the head.  If the rear cover is missing, replace it before continuing.  Good luck, Paul, hope this guidance helps somewhat.

I just want to add something about the tensioner too.  There is "freeze plug," or expansion plug that the steel tab(at 90 degrees from the rest of the tensioner), fits into.  At this point you have to have a special tool, called a "pin wrench" to get the remainder of the tensioner into position with.  It's NOT enough just to turn the rest of the tensioner.  Pin wrenches are available from any of the automotive specialty tool suppliers, like MATCO, or MAC, or CORNWELL, etc.  It may take a couple of days to get it, if it's not on the truck, but do get one to set the tension correctly.  There are 2 small pieces that align with one another on the back of the tensioner,  an arrow, and a pointer.  Try to get them right on the money, and your installation will last a good long time.  That's it.  Happy motoring.