Just to rule it out I had a strange sound a bit louder than yours and as I step on the gas pedal it become louder it was the a/t turbine if your car has auto trany just check it.

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did you say that you had had the valve cover off recently? possibly you left something in there?

or a big nut in the air cleaner.

sounds like something being thrown around the inside of the valve cover.

karl

Exactly what I thought it sounded like.....kindof a "whush whush whush, whap, whush whush whush, wap" sound inside the valve cover...when he put the camera closer to the cover it sounded louder....I bet its something in there......

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There I was thinking no-one cared about me, boo hoo, poor me, becuase I hadn't got any emails saying anyone had replied to my post, when I realized I hadn't subscribed to it.,

So I came back here and there are all the answers. Thanks.

I have used a piece of wood (works better than a tube for me) and haven't really been able to tie down where it is coming from. I think it is mechanical - and inside the valve cover.

I have had the valve cover off - I thought the noise might be the valves being loose. So the noise was there before I took the cover off. An experience mercedes mechanic friend of mine just listened to it and said don't run it anymore until you find what that noise is and remove it! He also thinks it is something loose in the valve cover.

I have checked the air filter. It is not the culprit. I think I need to do some snooping. Maybe something got in the air filter and is stuck in the intake some where? I don't know. First I'll take off the valve cover and check I didn't leave a spanner or something in there..... wouldn't that be unfunny! No worse than a surgeon leaving the scalpel in someone's stomach I guess...

I'll let you know when the mystery is solved.... then we can all go - ah yes......hmmmmm.. woulda never guessed that!

pulling bits out, especially from aluminum manifolds can be done with a piece of tubing with a magnet glued in the far end. use a piece of clothes hanger inside to steer it to each intake valve. that's a 240 right? no turbo to remove at least.

karl

if i will make a guess just to give you an idea, i'm not sure about this but try to take the valve cover off and check for the metal plate shroud that is riveted inside it (on the upper side where the breather vent is). there might be some loose rivets which makes the funny clacking noise when the engine vibrates. and since the valve cover is out, try to re-check your valve lashes and also check for timing chain tension. good luck!

I took the valve cover off again last night (getting good at it - took about 6.5 minutes...) and had a look around. No spanners left in the valve area, no loose bits.

After a bit of searching I did see that the one hole where the bolt goes through to bolt the cover on, had a piece missing. Looks like a metal shark took a bite out of it.

I am guessing the missing piece is the problem.

BUt I haven't been able to find it. After looking for a while, I used a magnet to poke around and see if there was anything loose that attached to it. I even pocked it down the air intake to see if I could pick anything up. I considered taking the intake off, for a better view, but didn't know the issues involved there.

Also poked the magnet down the slit at the back, near cyl 4 - I guess this is the oil drain? Anyway, nothing seems to be loose down there.

800Chedeng - how do I check the valve lashes and timing belt tension?

I thought about draining the oil and seeing if something fell out with it, and if not maybe taking the lower oil pan off. Not sure if something could make it all the way from the oil pan to the valves. Wouldn't it get caught in the oil filter? Maybe a copper washer from the last oil filter change dropped in there somewhere.....

Any ideas? Does draining the oil and taking the oil pan off sound like a good idea? Any better ideas?

Why don't you pull the valve cover again and try to tighten this down then see if it goes away?

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So I pulled the valve cover (again) and snooped around. Turns out the spring on the rocker arm assembly is on the wrong way (the retainer clip/spring thingy).

So I took the rocker assembly off and also found that the one rocker is uneven - it is worn at an angle such that the side of the camshaft lobe to the front of the engine is at about .016" clearance, and the part of the lobe near the back of the engine is at about 0". So I moved the rocker arm to see if it was the rocker or the lobe that was worn. Luckily it seems to be the rocker - becuase when I moved it to another valve, it was uneven on that valve too.

Also, the character of the clack has changed. It is more of a sliding sound now, without really clacking. So I think I am on the right track.

Is it reasonable to assume that a worn rocker arm could make that kind of noise?

I guess the real question is why did it wear? It could have been becuase some dork put the spring back on the wrong way, which allows the rocker arm about 1/8" of movement back and forth - that makes it go about 1/8 off the lobe, so I guess it is reasonable to think that it wore unevenly. Actually, that makes sense.

So whatcha think? New rocker arm will fix it?

I have some pictures if needed.

MBeige - it doesn't look like the oil bar (I found out that's what it is called) can be tightened down - the clips holding it are at max tightness, but actually, I am not sure, so I'll check. Thanks.

So i had another look - the one rocker that is not flat against the cam lobe, is also bent outwards, i.e. it is not 90 degrees to the rocker assembly arm. That is a problem in my book. Could it make the clacking noise? I don't know... what do you say?

Anyway, it is probably time for a new rocker, yes?

Rockers don't die, they just get warped and bent.....

Now what to do with an old bent rocker arm?

It'll make a nice coffee table piece...

As an earring it would definately start a conversation.

I would guess that the rocker is the source of your noise, but it should be replaced anyway. Hopefully, the noise will disappear when you fix the rocker.

I also noticed some pits on the side of the cam lobe. Is that a problem that needs fixing?

I put the new rocker arm on, and yes folks, it still has that same sound.... the clacking sound like something is loose somewhere.

I went all round the engine to find the sound with a piece of wood. It doesn't seem to be from anywhere. The only place where there is some strange sounds is the 4th injector. It has a sharp thwack, whereas the other injectors sound smooth.

So apart from dropping the oil pan and trying to find something loose down there, I think I'm going to swap the first and 4th injector and see if the sound moves. Not that I'll know what to do about it, but I'll figure out then.....

Any thoughts on the noise from the injector? Could it be something loose in the prechamber or something like that? I took the glow plug out and snooped around with a magnet, but nothing came out except a bit of carbon. It's quite black in there. Kinda like my mood at not finding what the problem is. .... Could it be majorly bad rod knocking?

Over and out...

Before you do any swapping, just crack the nut on the hard line to #4 to shut the cylinder down and see if the noise disappears. If it does, then you can swap injectors. But, I'll bet the noise stays with #4.........if it's cylinder related.

Don't see where compression test would solve anything - low compression should normally show itself by causing a hard to start when cold situation...

bnc