200tdi (def) timing belt noise.

[Maverik]

Deep sigh... so the problem of the screeching timing belt is back.

Started after a decent run, you hear what sounds like a fan belt slipping type noise, the only difference is like when this happend the other month, if you depres the clutch pedal the pitch of the belt noise changes slightly. - hence how I know it's the same issue. 

Someone in the related thread

said something about a warped timing chest... I can't get my head around how that can just happen - the chest was replaced by me with a new genuine one a few years ago, and it was find on the other block.

I guess my next step is to take the timing chest off try check it for flatness and re-mount as well as re-mount the fuel pump... kind of at a loss as to what else I can do, I'm assuming somthing is out of true, but I've been trying to get my head around why pushing the clutch changes the belt noise - I guess I'm effectively pushing the crank to one end of its float which shifts its position ever so slightly on the timing belt...

Has anyone got a spare def timing chest sat about they'd be willing to sell?

[miketomcat]

From what you have said I'd check the crank end float. Put a dial gauge on the crank pulley and get someone to push the clutch down. Depending on dial gauge I'd try it running to smack in the middle of the bolt should be fine for a short run. 

Mike

[Maverik]

12 hours ago, miketomcat said:

From what you have said I'd check the crank end float. Put a dial gauge on the crank pulley and get someone to push the clutch down. Depending on dial gauge I'd try it running to smack in the middle of the bolt should be fine for a short run. 

Mike

Hmm I'll have a look, need to aquire a dial gauge for that.

Having slept on it, whatever angle I come at this from I end up having to dismantle and abstractly start swapping out parts (like I have done already) in the hope that solves my problem. Not an angle I like to pursue. 

I followed the workshop manual too a T, used genuine parts where I could and used the correct torque tools etc. It's either an over worn part I've not seen or a defect I've not picked up.

I was thinking how I could check alignments, bar getting it laser scanned, this won't be an easy task and would I even be able to measure the amount it's out by using back yard tech.

So I figure land rover had a similar problem on the 300tdi (miss alignment of a belt pulley - causing the belt to run off) - they fixed it by putting sides on the crank pulley - et voila... 

I just purchased A 300tdi pulley with sides, I'll drill the spot welds and romove and then find a willing soul to tig weld them onto a 200tdi pulley...

 

[Bowie69]

A steel rule placed edge on to each pulley will give a good indication of whether the are out of true at all,  by amplifying any angle due to the length of the rule.

You can also buy laser belt alignment tools... some quite cheap (compared to a new timing case), which show you all the pulleys are right at the same time. 

 

[miketomcat]

You've already been in the belt casing which to me points to it being somewhere else. The fact the clutch changes it can only mean two things, the crank is moving back and forward or the engine speed is changing with clutch use. As you don't have a dial gauge clamp a steel rule close to the bolt with a light below. You won't be able to measure it but you should see enough to eliminate end float.

I suspect a 300 crank timing pulley is very similar to the 200 one and wouldn't be surprised if it would be a straight swap. Worth checking at the very least.

Mike

[Maverik]

48 minutes ago, miketomcat said:

You've already been in the belt casing which to me points to it being somewhere else. The fact the clutch changes it can only mean two things, the crank is moving back and forward or the engine speed is changing with clutch use. As you don't have a dial gauge clamp a steel rule close to the bolt with a light below. You won't be able to measure it but you should see enough to eliminate end float.

I suspect a 300 crank timing pulley is very similar to the 200 one and wouldn't be surprised if it would be a straight swap. Worth checking at the very least.

Mike

Ok, I'll jury rig a ruler and have a look at the float, to see if it looks excessive. 

I have a feeling a 300tdi pulley does different dimensions, it is a different profile at either end too you need to put a o ring on the inner side of a 300tdi.

Laser tool I don't will really help me here as I have a feeling it's a pulley that out of parallel with the others. 

[Bowie69]

Laser tool will show an off-axis pullet, or too deep/shallow pulley quite easily.

 

You could measure the end float with just a pry bar, feeler gauges and a steel rule, and a second pair of hands

[Maverik]

Let's re visit this picture, if anyone has any epiphanies...

[smallfry]

Could it be the bearings in the injection pump or idler ? A little bit of wear would cause a pulley to "tilt" slightly.

Or even the camshaft bearings ?

[cackshifter]

Looks like most of the dust is in one place. No rub marks on the cover I'm assuming.

[miketomcat]

The cover looks like its the idler/tensioner that's the problem. 

I had a timing chest fail on a discovery, it produced a tapping sound and wore a belt. The chest had cracked around the machined flat for the idler (idler and tensioner are separate on 200tdi discos), it just looked like a casting line at first glance. This caused the idler to tilt with injection pump pulses and hit the front cover.

Mike

[western]

Is the tensioner baseplate flat? 

It the timing case front cover straight & not slightly warped

Could be a crack in timing case rear as suggested above, when was the injection pump overhauled? 

[Eightpot]

It's quite easy to fit the idler pulley so it's not sitting square in the backplate  - you offer it up ok and by the time youve got the bolt in it shifts slightly and sits skewed but not noticeably so. Done it a couple of times myself.

[Maverik]

I've done so much work on this engine the past 10 months I can't remember the order of things off the top of my head, will refer to my wee log book.

Suffice to say  I replaced the belt, tensioner and lower pulley 4 weeks ago after it started to squeal, now the problem has returned, noisey timing belt.

[monkie]

Have you tried a different injection pump? I guess that would be the one thing on a rebuild (replacing parts as you describe) that could be over looked. I have a spare 200Tdi injection pump I can loan you if you want to try it. 

[Snagger]

I like Mike’s suspicion of the crank shaft thrust bearings being a little thin, as it does explain the changes when pressing the clutch as he said.

[Bowie69]

...but then it shouldn't be rubbing at all when foot off the clutch?

Even when the thrust bearings are née, there would still be some forward motion when disengaging the clutch, so if there was an existing noise, it would change.

[smallfry]

Pressing the clutch will alter the RPMs slightly, so that would alter the sound. Im with Bowie on this one, I would imagine the noise would become much worse when the clutch was pressed, if the thrusts were worn to any degree.

[Maverik]

2021-11-19, 178892 miles

New turners short block installed Inc timing belt, oil pump, clutch, fuel lift pump.

2022-01-23, 180082 miles

Sheaf diesel refurbished fuel injection pump installed (without removing timing belt).

2022-03-07, 181875 miles

Removed engine - replace and re-seal rear bellhousing due to oil leak - BELT NOISE first acknowledged on start-up after putting engine back in.

2022-04-02, 182435 miles

Opened timing chest, on removing crank damper belt noise stopped, on putting it back on (for test) noise came back. So replaced timing belt, tensioner and crank pulley amd crank damper, re-set FIP pump mounting position, observation - belt seemed to want to run against the outer lip of tensioner which put the belt about 1mm overhang off the FIP pulley.

2022-05-15, 184081 miles

Timing belt noise started again after a prolonged driving.

[western]

Could it be the crank damper touching the timing case front cover any evidence of fouling it that area on outside face. 

[smallfry]

1 hour ago, Maverik said:

belt seemed to want to run against the outer lip of tensioner which put the belt about 1mm overhang off the FIP pulley.

 

This really does suggest to me that one of shaft axes is "pulling in" and out of parallel, due to either wear or misalignment. This will cause the belt to be trying to walk off the front of the pulleys.

Crankshaft and camshaft run in the block so they are the least likely suspects, although if the cam bearings have been line bored, they could be slightly out. Just because Turners did it , does not mean it might be out !

As the tensioner is new, it might be worth trying another one, but the most likely candidate to me would be the FIP. Can you get hold of a magnetic base dial gauge, and see if there is any sideways movement in the shaft and pulley.

Could try slightly less tension on the belt ?

Sorry. Its all depressing stuff !

[Peaklander]

The 300TDi got a modified bracket I believe, to correct an inherent injection pump alignment and the consequent front cover distortion. Is there a chance that something has moved in your pump position during the engine removal?

[Maverik]

I'm pretty sure nothing changed during the engine removal, it was pretty uneventful, engine out, flywheel/housing off - new gasket back on and in.

I do have the old FIP pump still, there nothing stopping me from putting that back on I guess.

This is frustrating but I'm really struggling to come up a way of measuring the system out with laser scanning the lot!

I would have to agree, the most likely place for any miss alignment is going to be the FIP.

I had an idea to grind off the tensioner side wall, then rotate the engine and see if the belt wanted to crawl off.

Unfortunately the truck is my only transport just now so any off the road fixing needs to be carefully planned.

When I was playing with the belt last time, I fiddle about with the mounting of the FIP pump to see if I could alter how it ran on the pulley, but nothing I did seemed to influence the position of the belt around the system.

Just the areas of wear are all prior to the belt hitting the FIP pulley, to me it doesn't make sense that it's the FIP pulley throwing the belt off, when I open it up I might have a play at packing out the tensioner see if I can influence the belt running, it might give me a better indication as to where I need to be looking for a problem.

Also ordered a new bolt for fixing the tensioner, figure that could be stretching...

[pat_pending]

I've just skimmed through, and this...

4 hours ago, Maverik said:

Removed engine - replace and re-seal rear bellhousing due to oil leak - BELT NOISE first acknowledged on start-up after putting engine back in.

and this...

 

4 hours ago, Maverik said:

on removing crank damper belt noise stopped, on putting it back on (for test) noise came back.

Jumped out.

 

The noise wasn't there until you carried out a repair that didn't involve touching the timing belt, removing the crank damper stops the noise.

 

So unless I've missed something, why do you think the noise is coming from the belt?

[Maverik]

21 hours ago, pat_pending said:

I've just skimmed through, and this...

and this...

 

Jumped out.

 

The noise wasn't there until you carried out a repair that didn't involve touching the timing belt, removing the crank damper stops the noise.

 

So unless I've missed something, why do you think the noise is coming from the belt?

I know the belt is runnng off due to the rubber left on the front case, me removing the damper obviously allowed the crank timeing gear to shift slightly which gave a more favourable angle for the belt and it stopped squeeking, putting the damper back on pushed the crank gear tight which then moved the belt angle back. The noise was loud, before I pulled the case off I went at it from a few different angles and it alway sled me back to the front lower part of the engine.