[bde-19547]

I was given a 97 Jetta TDI with an AHU engine that had the timing belt go at 40K miles and of course crashed all valves, lifters and cam. There was portions of belt appearing to be melted to the intermediate shaft pulley which made me suspect vacuum pump or oil pump. The oil pump seemed OK but vacuum pump seemed to have some binding plus the port on the top was broken. The pistons did not have any visible marks on them so I replaced the head and vacuum pump. I got it all back together and it ran great except for a noise that sounds like a bad hydraulic lifter (at least what I'm used to hearing in say a gas OHV V8 engine). I've removed the oil fill cap and listened but nothing from there so I removed the valve cover twice and checked for noise while running and could not determine that it was a lifter problem. The noise sounds louder the under the car. Presently I have the pan off and checked the rod bearings visually and they all appear to be OK just normal looking wear. While each rod was disconnected I could not detect any play when pushing and pulling on the rods that would indicate a problem with the wrist pin end. What are the typical things that go wrong after a head is crashed? Is rod bearing damage typical or visible? Does anyone have an idea what I should be checking?

 

[chittychittybangbang]

The lower end is normally OK. With TDI, normally you just replace the head and it's fine. Worst case, the rod bends. This can be checked when measuring piston protrusion. That determines the head gasket thickness. If you didn't check you can just use the same number of punch holes and it should be fine. Maybe a lifter is not turning?

The intermediate shaft runs the oil pump. You say it was seized than it's possible there is something wrong there or in the oil pump.

 

[bioberkeley]

I had timing belt break while driving on freeway @65 mph. Oil light came on and I immediately pulled off. then an alarmed sounded and car died. Could not restart. Took to mechanic and he did camera inspection of head (???) after removing all fuel injectors and glow plugs. The engine was a VW rebuilt AHU with 55k on it. said all 4 valves were bent and possible rods broken; wants to install new engine. There also appears to be some oil leaking in engine compartment but pump and filter are secure. Question what damage can occur when TB breaks to this engine.

 

[chittychittybangbang]

I had timing belt break while driving on freeway @65 mph. Oil light came on and I immediately pulled off. then an alarmed sounded and car died. Could not restart. Took to mechanic and he did camera inspection of head (???) after removing all fuel injectors and glow plugs. The engine was a VW rebuilt AHU with 55k on it. said all 4 valves were bent and possible rods broken; wants to install new engine. There also appears to be some oil leaking in engine compartment but pump and filter are secure. Question what damage can occur when TB breaks to this engine.

The head must be rebuilt. The rods are usually OK. Once the head is off, measure piston protrusion to check rod height and if they're all within spec the rods are straight. You also need this to determine which head gasket thickness to use. You usually just use same one as old one but you have to check in your case. This must be a very fine measurement. I just realized your post has nothing to do with 1st post, but same advice.

The mechanic wants to install new engine because it's much faster/less messy and it'll clear his engine bay. New head is more work for him, more labor cost, but it should be cheaper. TDI engines are cheap though, if you can find a very low mileage one (unlikely), put a new timing belt and water pump on it. Your engine is supposed to have only 55k on it, worth reusing if possible.

 

[bioberkeley]

Is there any way to determine if engine is ok by just installing new timing belt without removing head? What is the best source for information on removing head? Are there any videos or which repair manual would be recommended? Thanks for response have limited internet access so took me a little time to respond

 

[chittychittybangbang]

If it broke while the engine was moving at speed, the inertia ensures it was damaged. If it was at a stop light and the injection pump spun but the cam and timing belt were in sync, it could be fine. But you were at speed. If you don't have a machine shop inspect the head now, the valves usually drop later and wreck the whole engine.

There's a DIY article in the FAQ for mk4, the mk3 is similar. If you want the manual, the bentley manual is what you need.