Thread: Manually Turning 300tdi

Use a 27mm socket and ratchet on the front pulley bolt to turn the engine over. You need to do this from under the car.

TDC is found using a timing pin, you will probably find more on this by doing a topic search.

I guess by your sig you have a 1998 model 300Tdi? As charlie said, the 27mm or (1"1/16) will fit the crank pulley bolt. It's worth noting here that 200tdi's and the very early (1994) 300Tdi's used a 1"3/16 size bolt.

JC

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sorry its been a long day I read this is as manually tuning 300tdi and the question as how I do the tappets........

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if your only chasing TDC for the valve adjustments you can do it by the rule of 5's

for a 4 pot, The cylinder that has its valves rocking subtracted from 5 gives you the cylinder that you should be adjusting... (rocking is when the exhaust valve is just about closed and the inlet valve is already opening)

So with the rockercover off and someone watching the rockers on top of the engine slowly bar it over (27mm socket on a ratchet with about a 2 foot cheat bar).. when the valve side of an exhaust rocker starts to come up they should warn you of this and watch the inlet rocker as you very very slowly bar the engine over when the inlet valve and the exhaust valve are both depressed the same amount you are at top dead center for that cylinder. 5-whichever cylinder that is and youve got the number of the pot that you can adjust both rockers at once on. repeat this process untill all pots are done, It should take you 2 turns of the crank to set them all.

that is my prefered method of adjusting 4 pot valves.....

The alternative method is after getting the first cylinder TDC with the valves rocking adjust all the rockers that are loose then turn the engine over 360 degrees so that #4 is tdc with the valves rocking and adjust all the rest.

you can make barring the engine over easier by A, making sure its in nuetral and B, removing the glow plugs, this also gives you an oportunity to see how well the engines running in much the same way as checking the plugs on a petrol engine will tell you how its doing. But be sure to clean out the recesses the glow plugs are in before removing them and to clean off the threads of the plug and the tip (just use something like brake clean and a rag, no abrasives) before re-inserting them.

adjusting the tappets requires a 14mm ring spanner (I might be wrong here its been ages since Ive done a TDI) a flat head screwdriver and a set of feeler gauges.

My procedure is a little different from the book but not by much..

I prefer to do the adjustment on a hot engine and its usually about the last thing I do as part of a complete service. you can do it cold But as a running engine is normally "hot" to me it makes more sense to adjust it as close to actuall running conditions as possable

set up your engine as described above and the way I do the rocker adjustment is as follows.

on a rocker that you can move by hand undo the locking nut on the outside of the adjusting screw, leave the ring spanner on the nut then wind the adjuster in all the way till the rocker goes "firm" now back it off about 1/4-1/2 a turn take the screwdriver out and slide the appropriate feeler gauge between the valve and the rocker then using the screwdriver untill the rocker just grabs the feeler gauge. the feeler gauge shouldnt bind at all and it should slde freely thorugh the gap it should be offer a slight resistance as you pull it out. now holding the adjuster with the screwdriver in the exact position its in tighten up the lock nut without letting the adjuster move.. check with the feeler gauge and it should be just a margin looser than it was but it should still be dragging the feeler. if your not happy go again ( I'll still do the first valve 2 or 3 times till Im happy with the second drag)

Once youve gotten one valve set remember how the feeler gauge slid between the valve and the rocker and as long as you adjust all the valves so the feel the same on the appropriate feeler gauges your laughing.

Best of luck on this.

WARNING

DO NOT TURN THE MOTOR BACKWARDS

This puts 'opposite' strain on the timing belt and may lead to it's failure soon thereafter. A mechanic friend of mine told me this was a common problem with some Holdens with timing belts. Not worth risking on any timing belt.

Originally Posted by Blknight.aus

*********edit***********

sorry its been a long day I read this is as manually tuning 300tdi and the question as how I do the tappets........

********endedit**********

if your only chasing TDC for the valve adjustments you can do it by the rule of 5's

for a 4 pot, The cylinder that has its valves rocking subtracted from 5 gives you the cylinder that you should be adjusting... (rocking is when the exhaust valve is just about closed and the inlet valve is already opening)

So with the rockercover off and someone watching the rockers on top of the engine slowly bar it over (27mm socket on a ratchet with about a 2 foot cheat bar).. when the valve side of an exhaust rocker starts to come up they should warn you of this and watch the inlet rocker as you very very slowly bar the engine over when the inlet valve and the exhaust valve are both depressed the same amount you are at top dead center for that cylinder. 5-whichever cylinder that is and youve got the number of the pot that you can adjust both rockers at once on. repeat this process untill all pots are done, It should take you 2 turns of the crank to set them all.

that is my prefered method of adjusting 4 pot valves.....

The alternative method is after getting the first cylinder TDC with the valves rocking adjust all the rockers that are loose then turn the engine over 360 degrees so that #4 is tdc with the valves rocking and adjust all the rest.

you can make barring the engine over easier by A, making sure its in nuetral and B, removing the glow plugs, this also gives you an oportunity to see how well the engines running in much the same way as checking the plugs on a petrol engine will tell you how its doing. But be sure to clean out the recesses the glow plugs are in before removing them and to clean off the threads of the plug and the tip (just use something like brake clean and a rag, no abrasives) before re-inserting them.

adjusting the tappets requires a 14mm ring spanner (I might be wrong here its been ages since Ive done a TDI) a flat head screwdriver and a set of feeler gauges.

My procedure is a little different from the book but not by much..

I prefer to do the adjustment on a hot engine and its usually about the last thing I do as part of a complete service. you can do it cold But as a running engine is normally "hot" to me it makes more sense to adjust it as close to actuall running conditions as possable
set up your engine as described above and the way I do the rocker adjustment is as follows.

on a rocker that you can move by hand undo the locking nut on the outside of the adjusting screw, leave the ring spanner on the nut then wind the adjuster in all the way till the rocker goes "firm" now back it off about 1/4-1/2 a turn take the screwdriver out and slide the appropriate feeler gauge between the valve and the rocker then using the screwdriver untill the rocker just grabs the feeler gauge. the feeler gauge shouldnt bind at all and it should slde freely thorugh the gap it should be offer a slight resistance as you pull it out. now holding the adjuster with the screwdriver in the exact position its in tighten up the lock nut without letting the adjuster move.. check with the feeler gauge and it should be just a margin looser than it was but it should still be dragging the feeler. if your not happy go again ( I'll still do the first valve 2 or 3 times till Im happy with the second drag)

Once youve gotten one valve set remember how the feeler gauge slid between the valve and the rocker and as long as you adjust all the valves so the feel the same on the appropriate feeler gauges your laughing.

Best of luck on this.

All as above other than setting when hot.

The only problem with that is that when a engine is hot it starts to cool while your doing the adjustment and this can make it so they are all different but only by a small amount but to me it is working against you doing it while hot.

When it's cold, it's not going to get colder at anytime soon so for me, it is best to park it on the friday night with setting the clearances in mind and doing them before start up.

But in saying that, you cant allways do them cold so like Dave said, do it after a test drive and get it up to op temp and do it as quick as you can.

Another point is that there is very little load on the timing belt as all the load is on the crank not the valves as all the timing belt ever has to push down is the valve springs so there is very little chance of doing damage to the timing belt by turning the engine backward by the crank.

If you were turning it from the cam shaft I would agree as then you are transfering the entire load through the timing belt but not if your turning it from the crank.

Thanks for the responses. I'll print off a copy of Dave's valve adjustments.

A couple of questions/comment:-

I searched "tdc and timing pin" as Charlie suggested, but didn't turn up anything.
Does the timing pin method require the removal of the timing belt cover; in other words is it easier to take the tappet cover off to find TDC?
For the brake vacuum advance pump fix, I guess the exact TDC is not critical anyway.

Dave said "...removing the glow plugs, this also gives you an oportunity to see how well the engines running...."
How should the glow plugs look for a motor that's running well?

Re Michael's warning on the timing belt raises questions like:-
a/ is there a memory effect like in tyres: it's best to always rotate in the same,
direction
b/ if so, would reversing the strain on the belt be more damaging the older the belt?

Thanks