piston tops 200tdi

[bushwhacker]

What is the best way to check for damage to the piston crown's. My timing belt has snapped. I have it stripped and the old belt off, I am going to look at the pushrods next and the rocker arm. Do I need the head off to check the piston,s?

When setting the timing mark,s are the cogs moved one by one in a clockwise direction or is the new belt fitted and all the cogs moved together in a clockwise direction?

This is after checking the piston,s and pushrods and making any repairs as necessary.

When a belt snaps does all the cogs stop in the same position ie when a new belt is put on and the crank turned over will all the marks line up when moving together? Or can one of the cogs slip on? I hope this makes sense.

Yours in deep distress.

[Les Henson]

If your piston crowns have been damaged by valve contact, then you will be the first person I have come across that has experienced it. The valves are in a straight line to the piston crown, so all energy is transferred to the pushrods (and in rare cases, the rockers). Repair is normally a new timing belt kit, a new set of pushrods, and perhaps a rocker or two (although this is virtually unknown on a 200TDi engine). The timing will have to be re-set, as the crank will turn after the belt has snapped.

Look in the tech archive - Thread by GBMUD, after he trashed his cam belt-

http://forums.lr4x4.com/index.php?showtopic=3945

Relative info-

http://forums.lr4x4.com/index.php?showtopic=14285

Les.

[bushwhacker]

Thank,s for the reply Les.

I have read the thread,s and printed them. So the pistons will be ok no need to check. And just to make sure each cog will need to be turned one at a time to line up the marks, lock the pump and the flywheel put on the belt and tension, turn crank over 2 times check the tension if ok see if it starts and runs ok. Sorry about all the questions I sound more like a detective than someone trying to mechanic.

Great forum I sing its praise to the other guys in the Northern Ireland Land Rover Club.

I will have to make more regular donations and get some stickers to promote LR4x4.com as it has saved me a few £s.

Thank,s for the help and taking the time to explain.

Yours in not just as deep distress.

[Les Henson]

Set the crank first, then the cam, and then the Inj pump. Make sure there is no slack between the crank and cam sprockets on the right hand run of the belt (this is important). Any slack in the belt between the cam and Inj pump sprockets on the top run are taken up by the adjustable sprocket on the pump. Other slack is removed by the tensioner. Rotate the engine twice in the normal direction of rotation - clockwise. The tappets will have to be reset because the new pushrods will be a different length to each other/the old ones. Make sure the valve caps are in place and not damaged (they sometimes crack in half) If any are missing - don't worry about it (just replace them),- they fall into the sump and stay there.

If you go off road at all, then use a bead of silicone sealant as well as a new gasket on the timing cover - the mating faces are not very good and water can still get through the join.

Les.

[JimAttrill]

I have seen lots of tdi pistons where the valves have left marks, sometimes quite deep, a mm or so. And also ones where the injectors have also hit the piston. It doesn't seem to do any harm unless the piston land has pushed down and jams the top ring. Check to see if the valves are still straight - they normally are.