MKIV jetta tdi stalled and won't turn over

[mesabeetle]

Okay, I need you seasoned Vdub wrench spinners to put on your thinking cap on. I was driving back to SoCal from Phoenix two weekends ago when my TDI wagon stalled at freeway speeds. The wife had to come get me with a tow dolley. I noticed that the engine would turn over more slowly than normal when I tried to re-start it without luck. When it stalled, I didn't hear or feel the obvious heavy clunking sounds of a bottom-end failure. After getting the car back home, I started troubleshooting. The first thing I did was to pull the "tee" on the fuel filter and take a peek at the fuel level within the filter. It looked kind of dry, so I replaced the fuel filter and tried to turn the engine over by key. After some slow rotations, it locked up. I then took off the passenger side tire and tried to turn the crank manually. It will spin counterclockwise but not clockwise.

I was able to get the valve cover today and do not see any signs of the valve lifters having any spider cracking or mushrooming or other damage. The lifters look perfectly flat and smooth. See pix. However, looking at the inspection hole on top of the tranny (not the hole that reveals the flywheel teeth, the second larger hole), I see like a notch or a cut-out portion of what I believe to the pressure plate. So before I pull the head to check valves, I am wondering if the Dual Mass Flywheel broke apart on me.





Anyone have experiences with these symptoms? I appreciate your input.

[taugust]

I am, by no means, a guru, but what happened to you sounds like what I have experienced twice. The teeth on the timing belt stripped off the belt. The mechanical timing stays correct, but the injection timing is off due to the injection pump pulley slipping instead of turning. Pull off the plastic timing belt cover and look at the belt. If there are any teeth missing, replace the belt. If you turn the engine over, everything will turn until the stripped area reaches the IP pulley, then it will slip. Hope this helps.

[mesabeetle]

Hmmm. After taking a quick look at the timing belt at the top of the engine, I could see that the timing belt teeth on that section of the belt look good. In fact, I replaced the TB and water pump about 4,000 miles ago. However, I admit that I need to remove the lower TB cover and take a look at the rest of the belt. I can see the logic of missing teeth on the timing belt resulting in the IP not turning. However, I don't think that situation would cause the engine to lock up. After I pull the the lower timing cover tonight, I'll post an update on what I find. Thanks for sharing your input.

[chittychittybangbang]

Possible tensioner has failed and timing has drifted far enough for injection pump to not inject fuel. Also, TB likes to strip at crank sprocket as well, less teeth there pulling the belt.

Also, PP has some cutouts so without seeing the whole thing, sounds like it's OK. Usually DMF don't cause engine to lockup. Also possible : internal injection pump problem.

[Seatman]

There was a thread on another forum recently where the pressure plate came apart and was hitting off the gear box casing, that could in theory prevent the engine turning over one way but it allow it to go the other way.

I'll wait and hear the results of the timing belt check

[mesabeetle]

Looks like the teeth on the timing belt are in very good condition. Again, this timing belt is only about 4,000 miles old. I tried to line up my timing marks on the various pulleys, but I can only turn the crankshaft a slight amount before it locks up. Again, the valve lifters show no sign of deformation; however, that doesn't mean I don't have a broken valve. So what is your vote? Valve hitting piston or grenaded flywheel/pressure plate?

[Seatman]

Pop the starter motor out incase it's got hung up on the ring gear.

[mesabeetle]

Huh, I never thought of that item. I don't recall ever hearing of starter getting hung up on the ring gear. It's worth pulling the starter to check though. So in other words, the teeth on the starter get jammed into the teeth and the ring gear even though the two spin in sync?

[Seatman]

Yep or a bit breaks off, I've seen it mentioned a few times now even though it's not common, does happen though and although it wouldn't necessarily explain the initial stalling it could be why the engine was slow to crank and now doesn't.

[mesabeetle]

I pulled the starter tonight, and then I tried to manually turn over the engine. I looked through the hole in the tranny case where the starter mounts, and the portion of the pressure plate that I can see looks good. I was secretly hoping that I would see fragments of the flywheel and pressure plate because then I would have reached a conclusion on my locked up engine. Still locked up unfortunately. So my best guess is that I have valve-to-piston contact, even though my valve lifters do not have any evidence of damage. I must have a valve that maybe broke and is wedged in the cylinder chamber. At least, that is the picture in my mind. Any more recommendations before I pull the head off the block?

Oh, and if I do end up pulling the head, shall I remove the turbo oil supply banjo bolt and pull the head with the turbo oil supply line attached to the head? From what I have read, it is darn near impossible to remove the oil supply line at the union with the head still attached to the block.