Thread: How to determine TDC on a TDi300 engine?

One can see that you are new! I once also asked logical questions "why is this like that etc. etc." That's the way it is, live with it!!!

Reason why they want TDC is to make sure that camshaft doesn't press on pump lever if your engine is by chance left in that position. Makes removal and fitting more difficult. Same goes for lift pump.

As far as TDC itself goes, I don't know from top of my head. Try searching forum here. I'm sure there are markings somewhere on the outside.

Easiest way to determine TDC on #1 is to pop the rocker cover off, put a socket on the crank pulley bolt and wind over till the rockers on #1 cylinder are 'rocking'.

That's as close to TDC as you need.

Vac Pump. Its not so much for removing the old one, but for reinstallation. If you take the old one off you will feel pressure IF its on top or on higher parts of the lobe, it will kind of push the vac pump against the nuts - undo them all evenly and you will be OK. You may have got lucky and theres no pressure at all, so no need to rotate the crank. For installation, you can see the lobe now, just rotate the crank till you can see or feel the low point - then there will be no pressure on the pump for reinstallation. So no real need to determine TDC on 1 - but if you do remove the rocker cover, might as well check the clearances while you are there.

Originally Posted by Spel1

Vac Pump. Its not so much for removing the old one, but for reinstallation. If you take the old one off you will feel pressure IF its on top or on higher parts of the lobe, it will kind of push the vac pump against the nuts - undo them all evenly and you will be OK. You may have got lucky and theres no pressure at all, so no need to rotate the crank. For installation, you can see the lobe now, just rotate the crank till you can see or feel the low point - then there will be no pressure on the pump for reinstallation. So no real need to determine TDC on 1 - but if you do remove the rocker cover, might as well check the clearances while you are there.

Thanks Spel1 for that explanation..... Much appreciated

Fly wheel has a notch in it that is used to insert the flywheel locking pin when the belt is changed.
Accessed via the bellhousing drain plug.

Two methods,
1, notch in the flywheel, you can see it or insert a smallish (say 4mm slot screw driver and wait for it to go in, I think it is about a 4mm drill bit gap. I have a tool, so never needed to know.
2, There is a mark on the crankshaft pulley, this is vertical IIRC (there is also an arrow on the front case which it aligns), easier to see with good torch and or the fan off.
Lift a wheel, put in fifth high and you can rotate the engine easily by moving the that wheel back and forth.
It is easish to do it from underneath while you look for the notch.
The pump is pumped in and out, not up and down or round and round by the cam, this puts the lobe as far away as possible for reinstallation.

Forgot about the flywheel notch, and have made my own lock tool !

FWIW the notch is 5mm.

Just be a little careful as there are two notches, obviously one isn't the TDC one.....

how badly is it leaking? all landrovers leak. my vacuum pump has been slowly leaking since i bought it. never have to top up oil on it. its just the nature of the beast. chance are you will reseal it and 6months later will start leaking again. if it's not a bad leak and just some oil stains down the block, i wouldnt bother.

others might disagree.