What's the clacking! (video attached)
 

Got a clacking in the ol' slug (1983 240D)

I've done a diesel purge (twice), replaced the injector nozzle from where the sound seems to be coming from 4th cylinder at the oil cover), adjusted the valves (lifters).

I even just replaced the front left wheel bearings, in case they were clacking... but no, it wasn't them.. (they needed replacing anyway)

So what is the clacking noise in the movie file at www.pauldrayton.com/uploadfiles/clacking.mpg ? (It's a 13 mb video file. A small audio only file is at www.pauldrayton.com/uploadfiles/clacking.wmv for the bandwidth challenged). The sound gets worse when you ride around for a while.

When I had the oil cover off while doing the valves, I noticed the bar that goes across the top, above the camshaft, has some play in it at the far end. But nothing that could clack like it does. I didn't know how tight the chain at the front should be (is that the timing chain?), so I couldn't really check it. The sound doesn't seem to be coming from the front though. I've listened with a piece of wood all around the engine. The only place I have heard it as on the oil cover at cyl 4.

Could this be the famous nailing? I didn't adjust the bozio nozzle I bought - I just stuck it in. I don't have shims to adjust them anyway - still waiting for the stealership to get them from Deutcshland uber alles. If this is a injector issue, then fine, I'll get them adjusted properly.

But it sounds like something moving and perhaps even slapping. Heck, you listen to it and tell me. If a picture is worth a thousand words, then a sound is probably worth about 435 words, so I'll stop typing now.

Some advice would be great. This is my work car and I want it working! :)

Thanks

It has a nice diesel sound to it. Except for that clacking sound. Have you tested compression?

You can get a compression tester at www.harborfreight.com.

danny

FWIW, it does not sound like injector nailing to me, it sounds mechanical. I can't think of anything obvious near the back of the engine. :confused:

That's definately a wierd noise. It sounds hollow and metallic like something hitting the inside of an big empty coffee can. I don't know if it's mechanical or a byproduct of the combustion process. Have you lifted the hard injector lines one at a time to try to isolate the position of the noise?

Don't listent to me, but I think it's just the normal vibration of the engine makes something clack in the engine bay while the whole block moves a little.

Just to rule it out, check the air filter housing to see if it is knocking in its mounts. Mine resonates a loud clack when it is loose. Good luck!

Just to rule it out, check the air filter housing to see if it is knocking in its mounts. Mine resonates a loud clack when it is loose. Good luck!

I was thinking the same thing. Mine had a noise similar to that when I 1st got it. It turned out the air filter bracket had broken.

Not an injector
 

I'll agree with those saying the noise is mechanical. Check for broken air filter mounts or anything else that could be loose or broken that could come in contact with the engine. It's pretty loud, so I'm guessing that it will be something made of thin (sheet?) metal that resonates a lot when the contact happens.

Yeah, it sounds like some thing that is attatched to the engine or in the engine compartment. Check the flex joint off the turbocharger (if equipped)
there might be a bracket loose or something...

Another possibility if your exhaust, maybe the bracket came loose and is rattling. Unlikely but worth a check.

My car sounded like it had a tin can banging around under the hood shortly after I got it, then the water pump started weeping, so I replaced it (original I believe, it had 214k on it! :eek:) and the can sound was gone! :D Just an idea, and thats at the front of the engine but sometimes where the sound is coming from is deceiving.....

Yeah, there are a lot more possibilities if the sound is from the front of the engine, like the vacuum pump that just ate itself on my 617.:mad:

Just watched the video and have to admit that its quite an odd sound....the vision I got when watching/hearing it was of something going "scrape..scrape....tap....clank...." inside the back of the valve cover.

Thats what it sounded like to me....what could do that in there? Is that even possible?? :confused: Then again the sound could be the bottom of the air cleaner banging on the arm it sits on.....but it seemed like its coming from the valve cover....

It sure doesn't sound like an air cleaner bracket to me. It sounds like a loose mechanical part that keeps changing position (maybe rotating), I just don't have a clue what it could be.

Could a loose pre-chamber "ball" make that sound? Just a wild guess.

It is almost impossible to determine the source of this sound over the internet. As mentioned, it sounds like something external to the engine.

Get a piece of hose, about 1.25" diameter or so, and put one end in your ear and the other end at various points around the running engine. The hose amplifies the sound and you'll likely be able to home in on such a sound if you are patient with it. It might be beneficial to have the vehicle on ramps so that you can go underneath it while it's running........but.......be careful.......that fan is no pleasure if you bump into it with the hose.:mad:

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.

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......

so much for that!
 

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!

Evidence, but no conviction....
 

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?

rocker uneven
 

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.

bent rocker
 

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.

scratches on lobe
 

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

New rocker arm, same sound GRRRRRR! :(
 

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

noise stays with cylinder
 

When I cracked the nut to the injector 4, the noise stays there.

There is still a thwack/crack sound when using a 'stethoscope' on the injector line itself, that is only apparent on 4. What does that mean? If the injector pressure is set wrong, would it thwack like that becuase it is early or late in firing?

diget69 - the slug starts 1st time everytime in the mornings. Never had a problem starting, so I don't think compression either.

If you cracked the injector and the noise remains, it's not injector or combustion related because the cylider is not getting any fuel.

Back to square 1.

I could not get the video to work.:confused:

OK, I know what the noise is.
 

this is DEFINATELY the noise so no need to go any further. notice in the video upper right side of the screen, small green fellow with a hammer? put out a mouse trap baited with hemlock. noise will disappear.
:fork_off: :sick2: :rocketwho :sword2: :jigga: :devil: :mgwhore2: :huepfenic :dark: :bounce:

Brian, itcould still be something loose in the chamber though, couldn't it?

Dieselgiant - sounds like you don't have the mpg codec on your computer, so you can't play the video. There is a slightly bigger, but more generic video at
http://www.pauldrayton.com/uploadfiles/MVI_3619.avi
also, there is a sound only file at
http://www.pauldrayton.com/uploadfiles/clacking.wmv

BTW, I happened to be reading another post about hydraulic lifters and the guys were saying that synthetic oil can help. Also they said that Rotella synthetic sucks. I happened to just put that oil in my car about 500 miles ago. I wonder if it loosened something?

thanks.

Your linkage looks like it's moving/vibrating quite a bit. Try some ATF or bearing grease in the ball joints.

Sorry for the attempt at humor
 

anyway, after listening to the video again with my surround sound turned up, it really sounds like something loose in the exaust pipe banging around... it also sounds like it is NOT coming from the valve cover. have you ... I know this is going to be messy and dangerous, but run the engine with the VC removed? this would eliminate for sure anything in the valve area.
have you checked the exaust pipe for something rattling? it could be as simple as a rock stuck on the collector pipe...
ok if that turns out negative, do a compression check on every cylinder... it could be a broken rod banging around, but it does not sound that loud.

I hope you mean ring... :D

No that is NOT a rod noise. I have heard that noise before but I dont know what it is. I have heard it in Nissan Altimas and I believe that it was lifter related, but I cant remember exactly what caused it.

I am starting to think it is lifter too. But what about the lifter? Do I have to take the cam off to really tell if there's a problem?

I had the VC off my wife's 124 and could tell the hydraulic lifter was bad becuase I could push it down with a finger. But how to tell with the spring lifters on the 616?

I'll check the exhaust stuff too, thanks for the tip.

Wouldn't a bent valve cause a similar noise?

punky, I don't know - but I hope not, because it is hard to remove a valve isn't it?

I took the oil filter and intake manifold off - there is nothing I could find loose in the intake. The noise is louder with the manifold off.

My next step is to move the injector and see if the noise moves with it.

Absolutely. But, it's not injector.......or fuel........related.

after a LOT of messing around
 

after a LOT of messing around (taking the exhaust manifold off. etc) I tightened down the exhaust valve on 4 to intake specs, and it was a lot quieter. The noise is still there, but it doesn't get clacking loud at all, just a kind of sound like a too open valve gap.

So I don't know what that means, but at least there has been change.

I did the valves again, and did them better this time and the engine sounds really good. No tapping or anything, except for the noise above, which is intermittent and stops at higher revs.

I am still thinking of swapping injector 4 and 1 to see if the thwack I hear on the injector line moves with it or not. I am thinking maybe a badly set nozzle would fire early and cause stress on the cylinder and make an iffy valve noisy?
Whatcha think?

Anyway, still haven't really found what is making the noise, but I'm pretending it will fix itself.... :)

UM, yeah it will fix itself... sure, but will the car run after that?
 

:eek:

Strange thing I forgot to mention
 

Strange thing I forgot to mention is that the engine seems to stop in exactly the same rotational position everytime. When I was replacing the rocker arm, I noticed the engine always stopped at exactly the same place. I noticed becuase I could easily remove the rocker arm everytime.

Is that an indication of something?

As a recap, here's my symptoms and attempted cures

Clacking noise that starts when the car gets warm. Is a lot quieter with the 4th cylinder exhaust valve tightened down to 0.06" instead of 0.13".

The sound is like something loose in the valve cover flying around, or like a loose bracket slapping against something. It is coming from the back of the engine on the air filter side.

I have taken off the intake manifold and injector and glowplug and poked around with a magnet - nothing came out. I also turned the engine over with the glow plug removed to see iif it would spit something out.

The other symptom is a hard sharp thwack when you put a steth on injector line 4. You can feel it with your hands too. But since the clacking doesn't stop when the injector line to 4 is cracked open, I don't think it is the injector, so I haven't really bothered investigating it too far.

So what to do next? This is the first synthetic oil change I have done, so mabye some major sludge or who knows what came loose?

It's a lottery. And my darling slug has been sitting idle for 2 weeks. I did take her out for a spin after I filled her up with my first full tank of homemade B100......

Have you rotated the engine, manually, to see if the noise might persist? I'm doubful, but, with the engine stopping in the same place each time, a manual rotation via the crankshaft might tell you something.

yes
 

yes, I've turned it over manually lots of times to set the valves. I think I was turning it the wrong way (anticlockwise) in the beginning, and it was hard to turn every now and then. But going forward (clockwise) I didn't notice anything strange.

Could I have screwed something up turning it backwards a few times?

I doubt that you damaged anything by turning it counterclockwise. It's not a great idea because the chain can possibly catch the bottom of the tensioner, but, you'd know this right away. It might have been the "hard to turn" scenario.

You mention that the noise is not from the front of the engine, so, I tend to discount any damage to the tensioning rail.

HA! Found it!
 

WEll, after a lot of soul searching, sleepless nights and soaking myself in spirits (OK, not really), I found the source of the clacking.

Remember in the beginning I said it sounds like something flying around in the valve cover (You don't remember?) Well, it IS something flying around, but not in the valve cover. The sound is deceptive. It was actually coming from the torque converter. When I took the cover plate off the front of the tranny housing where the flex plate is, I saw a nut and washer loose in there! Just hanging out in a groove between the flywheel and the tranny housing....

They're stuck in a funny position where I can't figure how to get them out, or how the heck they got in there. All I can think is the owner before me put on a new tranny and left an extra bolt in there for a surprise. Thanks buddy.

So now, apart from taking off the tranny, I don't see how the heck to get the nut out. The car is hardly clacking at all any more - I've been driving it around - so maybe the nut will wear itself out. Or maybe it will wear down enough to turn 90% and destroy the flywheel? I don't know.

Tomorrow I'm going to buy a magnet and see if I can coax it out somehow.

Thanks for all the suggestions, especially the chap who said to check the torque converter for a rock stuck in there./..... The sound was really deceptive, I could have swore it was coming from the valve cover. :rolleyes: