4,2 D4D Timing Belt Change - Help!

[turco]

Evening all – looking for some help please.

I’m pretty handy with car stuff so decided to have a go at changing the timing belt on my 4.2 D4D today using Anchormans excellent guide.

All was going well until I tried to slacken off the serpentine belt tensioner – no way could I get the centre bolt slackened. Ended up taking out the headlight so that I could get access to get a socket onto it. A real pain.

Rest was pretty straightforward except that I forgot to highlight the timing marks before removing the old belt. Still -- got the new belt on and lined up the camshaft, fuel pump and crank using the pulley marks and this is where I hit a problem and could do with some advice.

Lined up crank, then fuel pump and cam but the cam looks likes its half a tooth out? If I move it a tooth on the belt it seems like its half a tooth out the other way if that makes sense.

Even tried the old belt back on so its not a problem with the new belt.

So its something I’m doing wrong. I’ve tried using the edge of a hacksaw blade using the centre of the cam bolt, the mark on the pulley and trying to line up with the top of the cylinder head but its always half a tooth out. Don’t want to put it all back together and do some damage.

HELP!!!! please

Turco

[jedi134]

Not sure about your tooth problem, but once all together I would pull the heater plugs and turn the engine by hand just to be sure there wont be a collision

[turco]

Thanks for the quick reply Jedi. Yeh I've had the heater plugs out and turned it over a few times with a ratchet on the crank bolt. Turns over OK with the cam in either belt position - a half a tooth before the mark or half a tooth after the mark. One must be the right one but I'm just missing something when lining up the marks.

Thanks

Turco

[jedi134]

Not sure what half a tooth before/after would do?

May even run better???

[Mistermena]

Evening all – looking for some help please.

I'm pretty handy with car stuff so decided to have a go at changing the timing belt on my 4.2 D4D today using Anchormans excellent guide.

All was going well until I tried to slacken off the serpentine belt tensioner – no way could I get the centre bolt slackened. Ended up taking out the headlight so that I could get access to get a socket onto it. A real pain.

Rest was pretty straightforward except that I forgot to highlight the timing marks before removing the old belt. Still -- got the new belt on and lined up the camshaft, fuel pump and crank using the pulley marks and this is where I hit a problem and could do with some advice.

Lined up crank, then fuel pump and cam but the cam looks likes its half a tooth out? If I move it a tooth on the belt it seems like its half a tooth out the other way if that makes sense.

Even tried the old belt back on so its not a problem with the new belt.

So its something I'm doing wrong. I've tried using the edge of a hacksaw blade using the centre of the cam bolt, the mark on the pulley and trying to line up with the top of the cylinder head but its always half a tooth out. Don't want to put it all back together and do some damage.

HELP!!!! please

Turco

I'd PM Don and ask his advise if he wrote the guide!

[anchorman]

Well! As long as you have fitted the new belt IN THE ORDER SHOWN AT THE BOTTOM OF PAGE EM19 and got it right at the crankshaft and then the fuel pump should line up. Now - if necessary you need to nick somebody's make up mirror. With the tensioner in place, turn the engine clockwise a whole turn with the jacked up wheel. You can do this and peer into the engine at the same time. Line up the crank first and check that the fuel pump looks something like. Look at the tooth nearest the line on the head and if it still looks a half tooth out, remembering that you only need to turn the crank a fraction to move the cam a long way, eyeball that mark you think is half a tooth out. Put a chalk mark on the tooth either side of the one that looks nearest. This is where the mark will be if you turn it by 1 tooth. You can only get it to the nearest point so as long as you have satisfied yourself that you are as near as you can be, stop worrying. Now turn the engine a couple of times and check it again. Only ever turn clockwise and if you miss the mark go around again. Remember that under load the toothed wheel will lag and not go forward.

If its only a bit out don't worry. If it is a tooth out try again but you will know that when you look at the chalk marks.

[turco]

Thanks for the detailed reply Anchorman. Brill as usual. I couldn't get to sleep for thinking about it and I think I've just worked out where I'm going wrong. With the marks not lining up at the cam, I've been trying to move it a tooth either way at the cam pulley but still keep being half a tooth out either way. But........... as the crank turn twice to one turn of the cam, then half a tooth at the cam equals one tooth at the crank so I'm thinking its the crank I need to move the belt by 1 tooth. It will make the pump out very slightly but I'm thinking that its there for building up fuel pressure and the actual fuel timing is done by the ECU and injectors unlike older diesels that were timed by the pump.

If I didnt think that I'd upset the neighbours, I'd try it tonight!!!

So early rise tomorrow to try this out.

Turco

[anchorman]

I think those two marks on the crank and the fuel pump just ensure that you haven't got a tooth slack between the two pulleys. Turn the cam clockwise to the correct mark on the head then see where the crank is. A tooth out will be a mile away.

[turco]

Yeeehhhh! got there in the end! Many Thanks Anchorman for the advice. Like I said earlier, turns out I was trying to adjust for the error at the wrong pulley and should have done it at the crank pulley. Started from scratch as per Anchormans instructions and it lined up first time. Phew!

A couple of tweaks to Anchormans brill instructions that might help others having a go at this -

1. I had to take the headlamp out to get at the adjuster nut for the serpentine belt but even though it was a pain to get out, it improved access so much that I would do it again if I ever have to do another timing belt.

2. I found it easier to leave the top timing cover until after the engine mount was off the bulkhead as I couldn't get it out otherwise.

3. I used a small allen key to keep the tensioner plunger in place - it lets you get a good grip and twist it as you remove it. Because the headlamp was out, I was able to use a long screwdriver to gently lever down on the tensioner arm and the allen key pulled out no bother.

Engine started fine and now got peace of mind that the new belt is good for another 5yrs/60k miles.

Thanks once again to Anchorman for the "how to" guide as I dont think I would have tackled the job without it.

Kenny

[anchorman]

Well done Kenny - that has saved you a small fortune. I've got a drawer full of metric spanners I've accumilated over the years and I found a cranked spanner that just fit into that recess. The proper service tool is a wierd looking thing about a foot long with a bend in the length and a deep shank. In the past I have used lengths of rope to pull a spanner or a good piece of hardwood to lever one and all sorts of other methods. I never thought of taking the headlight out. I did use a small allen key for the tensioner as I think a pop rivet bent - it has a surprising amount of pressure on it doesn't it!

The next time I do that black one will be at 10 years at which time I will renew the tensioner pulley, water pump and the auxilliary belts.

Glad you are sorted.

[turco]

Yeh - deciding factor was a quote from local garage - £682!!

Chuffed that I did it but got a few aches and pains today - getting too old for all this crawling about under cars malarky!

Kenny