New 85 300D, Engine knock
 

The 85 300D I just got has a bad knock in the engine, here's the video

http://www.youtube.com/watch?v=vJVoQsqLTa4

Car came with a bad starter, got that working, adjusted the valves, replaced the glow plugs and fired it up, ran a can of diesel purge though also. Took it for a little drive, car has gobs of power... Any idea what the knock is? previous owner told me about it, said he'd been driving it that way for the last year before the starter gave out.

No evidence of a broken valve spring when adjusting the valves? Not a rod knock. Vacuum pump? Seems too high up for that. Sounds like it's in the valve train. Use a stethoscope to narrow it down.

Didn't notice anything, it was actually very clean. You could tell that it had not been adjusted in some time. Every single one was way tight. Other than that knock, it seems to run great. very little evidence of blow-by or burning oil.

previous owner said he had his mechanic look at it but he could pin point it either. Said it sounds like it was in the upper engine.

I'll try using a broom stick in the am to see if I can get closer to the sounds area.

The whole valve train sounded loud to me. Can you see oil being flung around with the fill cap off and the engine running?

suns almost down so Ill have to check in the morning. How about running the engine with the valve cover off? I'm guessing that would be a huge mess....

Yeah, that's a messy proposition.

Sounds like the fan hitting the shroud or the belt hitting the the diagnostic sensor.

All good suggestions, hopefully I'll know more today. I had a rover once, wife pulled into the driveway with a similar knocking, turned out the be the alternator. Its so hard to tell without a stethoscope. Guess it might be time to invest in one.

I still don't believe it's something inside the engine yet. If it turns out to be I'm tempted to go ahead and get another engine for it. The car itself is in almost to good of shape to part out.

My impression is that the noise is not an engine killer. How long has it been driven with the noise?

I know its hard to count the frequency of the tapping, but if it is the same as engine RPM it is crankshaft related and if it is 1/2 engine RPM it is valve train related. Or do I have that backwards?

600 RPM idle will rotate the crankshaft 10 time a second. Your tapping didn't sound like 10 taps a second, it sounds slower than that.

Some suggestions:

1. Vacuum pump -- have you checked the main vacuum supply?

2. Alternator shaft bearing failure, had this happen once and the noise was extremely hard to pinpoint, seemed to be coming from 'everywhere'

3. Timing chain tensioner spring? Have not had this happen myself but have been told it makes a clicking sound.

4. I have never had an injector sound like that, I would expect a more 'hammer' sound... but have you cracked the lines to check?

5. Fan hitting shroud -- I drove myself half insane trying to figure this one out once... I had leaned over on the shroud and pushed it down far enough for the fan blades to just barely touch it.

Looks like a nice car, btw....

Going out to check the main vac. I bought a stethoscope, could not pinpoint the noise, but the alternator sounded fine with the scope right on it. I've done the injector cracking, they are all fine.

It's something goofy... I took it over to my Diesel mechanic buddy and he gave it a look over also... He also took his scope to it, and again could not pin point the noise. Car has plenty of power, more than my 300CD. Of course the belt for the A/C is off, so that makes a difference.

My thought on this is simple... just live with the noise until something goes. Car drives great otherwise. PO drove it a year like this... When and if it goes then maybe put the engine from my 300CD in it and get a new (rebuilt engine) for the CD. which would give me a chance to really have the car gone though and repainted (color change).

In the end I want the CD nice... The D'd are all just drivers.

This sounds very much like my noise except this is more advanced. Mine starts making the noise at about 1100rpm. At idle it does not make the noise. I so far think it's either a piston problem or injector pump/injector noise. The car has loads of power, very little blow by or oil consumption, and a smooth idle. I will be interested in what you find.

It's literally a 500 dollar car... so Im not going to go too deep into it. I'm just going to drive it. Everything seems to work, even the cruise control, I can live with the knock. You can't even hear it over the cars normally high noise at speed. I had the old starter sitting here, so it was free to rebuild. I also had the set of new glow plugs and the new valve cover gasket sitting here. So literally my total in this car is that 500 bucks. If the engine goes, I still have a wealth of parts for my other ones.

Running it into town now to get the plate on it. and going to drive it to Huntsville Al, which is about a 2.5 hour trip each way for me. Will be interesting to see how it does.

My compressor mounting bolts were loose, causing a lot of noise. I tightened them and the noise went away.

I had a similar tick, ended up removing the cruise control actuator. Although yours sounds just bit louder.

Drove it 300 miles today... ran great, most the trip i was on cruise control doing 70, at some points I hit 90 just to see.... I verified the speedo was correct using my gps.

Before I left I noticed a new A/C belt in the trunk, so I tossed it on, charged the system, swapped the kilma from my 300CD and got cold air. The tach does not work. there are a few times I noticed it try to work when I would really kick it down. The trip including 4 different mountain climbs, some city driving etc... really a taxing trip on the car, but not an issue. So, whatever this knocking is it does not seem to be effecting the car. I did have the car run for a second without the power steering pump hooked up, so I can rule that out. THe A/C compressors tight, since I just did that. When I put my stethoscope right in the alternator, it sounds fine... so I'm ruling that out.

This has stumped multiple mechanics, so I'm not going to feel to bad if I can't figure it out, but It would be a nice feather in the cap...

Just as a last check have you looked at the engine mounts and the trans cooler lines? I know a friend of mine had the mount heat sheilds bent and they ticked when the engine was running, I forgot what they were hitting.

My cruise control actuator was clicking also, but not quite that loud. When I put my had on it I could feel the sound.

I've come to determine that the noise is loudest in the front of the engine, piston 1. I pulled off the valve cover again to take a closer look. There appears to be a fine "sand of metal shavings mixed in with the residue oil in the cover. My best guess here it that although this engine is performing well, not smoking, and seems to have plenty of power that there is an issue with piston 1. Might look into rebuilding the engine, but it would be a real learning curve... Looking for another engine to stick in there for now and might just go ahead an grab the one out of my CD. I have to take that engine out of the CD anyways to repaint the car so no real extra work. I would like to fined a nice low milage engine to put back in.

Your sound is exactly one-half engine idle speed. So, the noise is probably restricted to the camshaft or the injection sequence.

The noise is a metallic tap, therefore I'd discount the injectors as the source.

I'd take a closer look at the camshaft and lifters before doing anything else to the engine. It would be hard to condemn the #1 piston if the noise is not repeating at engine speed. It could, of course, be contacting a valve...........which might become obvious if the valves are way out of adjustment.

First thing I did was go in and adjust the valves thinking the same thing. no change. cracking each injector made no difference, except to show me that each was working fine.

The fine sandy texture of metallic particles i'm seeing in the valve cover does lead me to believe that whatever is the problem is causing a good amount of engine wear someplace. I think the best approach is to locate a good donor engine and swap. Then, I can take this engine and tear into it and see what the real story was.

Someone around me should have a good motor sitting in a crappy rusted out car, plus I could use some other parts off one, like a piece of rear quarter glass for the the back passenger door...

If I get into the engine and find It's a simple fix at that point, then I have a spare :)

What does get me is that even with this noise and the particles, the engines is not smoking and is showing very little blow by.

Is there any way for me to check the timing chain without having that special tool? if not, is there a place to get that tool cheap? maybe even used? Since I'm up to 4 of these right now maybe it would be time to start tooling up for them.

Also, does anyone offer a rebuild kit? whats the best approach to a rebuild? Some of the rebuild numbers I have seen on here seem way out of line with the value of the car.

You find metallic particles under the valve cover, presumably caused by the camshaft and/or lifters and you have determined that you want to "tear into it" to locate a problem inside the cylinders?

I've already told you that the tapping is exactly one-half engine speed.........thereby directing your efforts toward the camshaft or the injection system. You've properly ruled out the injection system.

You're baffled by the fact that the engine runs well with no smoke and little blowby although the engine is trying to tell you that its cylinders are fine and the issue is with the valve train in some fashion.

You remind me of most doctors who tell you your problem before the exam is complete and a careful analysis of the tests and symptoms is performed.

No, I'm just assuming that since I see that sandy stuff, the damage most likely as already been done. I ran the car yesterday without the valve cover on... messy, but I didn't see any issue. The cam itself looks perfect. no noticeable wear on ay of the lobes. I also hand turned the engine and checked every link in the timing chain, plus looked for anything that might be in there and making the noise.

In looking at this diagram, http://www.peachparts.com/shopforum/...6&d=1313759215

I see wear on the end of the part I circled and labeled 1. On the part I circled and labeled 2, I noticed that the "shaft" does not line up with it's counterpart, allowing the main part to from side to side (front to back on the engine). In running without the valve cover on, It did not seem to be the source of the noise, But maybe to source of the sandy residue I'm seeing?

The metallic tap is likely due to a an excessive clearance of........maybe .050". Do you think you're able to "see" such an issue? I'm sure I can't.

Can you provide any scenario where such wear would result in a metallic tap that is exactly one-half engine speed?

Can you provide any scenario where the metallic particles generated by such wear would migrate up and over the top of the block to get inside the valve cover?

That's a proper conclusion.

True But I did a full valve adjustment, and it's correct now. before i did the adjustment, all of them where really tight. REALLY tight. Like it was the first time it had been done tight. The adjustment to within spec made no difference on the noise. I did the readjustment with the engine cold. (sitting overnight)

Unfortunately no. please keep in mind that this is totally new to me.

Again no. I'm learning slowly, but is only the second time I've ever even seen the inside of the valve cover, I've did a valve adjustment on my cd, but have a feeling I should go back and do it again just to make sure.

sweet. so I can at least rule that out.

The sound seems to be coming from the area I circled in that diagram. at least, from the outside with the engine running that's the loudest point. Which is why I looked at it in the first place.

It's absolutely possible for the tensioning rail or the tensioner (the items which you circled) to wear significantly. However, I cannot grasp any scenario where this wear would result in a noise that is once per every two revolutions.

Maybe others have an opinion.

What if I loosen up the valve a little more on the first cylinder? Would that give it a greater clearance? And maybe help? I'll go pull the cover off again and get some good pictures of everything in there.

Yes, it would give greater clearance.

Now you'll have two different noises at one-half engine speed....................


I thought we understood that the noise is caused by a clearance on the order of .050" somewhere? We also determined that one cannot visually see .050" in almost all cases unless one knows exactly where to look.

We all are quite clear about what is under the valve cover and the results of a photo from two feet won't enhance that knowledge.

Well, here are some pics anyway.....

Lobes all look fine... But we have established that.

http://www.peachparts.com/shopforum/...0&d=1313763732

Notice the wear?

http://www.peachparts.com/shopforum/...1&d=1313763972

Here you can see the misalignment I was talking of

http://www.peachparts.com/shopforum/...2&d=1313763985

Here's the crap in the valve cover...

http://www.peachparts.com/shopforum/...3&d=1313763998

And last but not least the crap from the cover on my finger...

http://www.peachparts.com/shopforum/...4&d=1313764014

I was going to do a quick test of the chain stretch, by lining up the timing marks and then seeing where they lined up on the crank.... but It seems to line up with the counter weight. when I turn the engine to the crank timing marks I see nothing to line up on the top...???

http://www.peachparts.com/Wikka/OM617TimingChainStretch


Go to step #10.

Yes, this is the guide I'm following. When I have the marks lined up on top, im not even close to the indicator on the bottom. I've tried to rotated the engine around a couple times to see if I could get it there but no go. Is it possible for my timing to be that far off?

See, When I have the timing marks here....

http://www.peachparts.com/shopforum/...5&d=1313774609

At the crank I'm here.... (the crank weight before the one on the crank that has the timing marks)

http://www.peachparts.com/shopforum/...8&d=1313776067

If I rotate the engine so I'm at 0 at the crank, my timing mark on the top is here....

http://www.peachparts.com/shopforum/...7&d=1313774672

My next question would be that if it's this far off, how is my engine even running, let alone running as good as it is (less the knock)

You need to take a better photo of the crank...........the second photo is useless at the moment.

Fixed....

http://www.peachparts.com/shopforum/...8&d=1313776067

Being that I'm old, I cannot read the degree marks on the damper.

Maybe somebody else can read them...............;)

Thats the point... it's no where near the correct damper...let alone the marks... When the timing marks are lined up at the top of the engine, that's what you see on the crank...

If I turn the engine so that I'm on the correct marked damper, at zero, then the timing mark at the top of the engine is whereI show it in the 3rd picture.

The camshaft cannot be out by the amount indicated or the valves would hit the pistons on one of the strokes.

Apparently, some moron was involved with this engine and, therefore, all bets are off as to what was done.

You really don't have much choice but to procure the equipment to measure the chain via the 2mm valve lift method as indicted from the beginning of the procedure.

Hense the pounding noise it's making.....

So could I set the mark 2 zero on the crank, remove and rotate the top till the marks lined up and reassemble?

I'm going to run over to a friend that rebuilds diesels and see if he has a dial indicator I could borrow...

Pounding noise??

Conclusion based on a misalignment of some marks??

The camshaft pulley is keyed to the camshaft. You cannot rotate it.

Did you read and understand what I wrote in post 38?

ok, now I'm just confused... What's the point of the gauge If I can't alter the timing?

What I'm saying is to set to mark to zero on the damper, then remove the bolt from the cam pulley, and remove the chain, from it. then put it back on enough to rotate the pulley AND the cam to to line up the marks and put the chain back on.... Wouldn't that get me at least close?

And in all honesty, with the amount of time I've already spend messing with it, I could have pulled the motor and had another engine swapped in it's place by now...

The point of the gauge is to confirm or deny the data obtained from alignment of the marks. We don't believe the data from the marks is accurate because the engine won't run with the camshaft so far out of time with the crankshaft.

If you proceed with this approach, based solely upon your data from the marks, you're probably going to get into the "epic fail" mode........whereby return is almost impossible.

Hmmm............two hours of discussion and measurement and you could have swapped an entire engine............damn, you're good..........you're very good.

LOL... no, I've been playing with this since Saturday....

My questions then is this... The cam pulley is keyed to the camshaft right? So it can only go on one way. That means if I hold the chain in place, remove the cam pulley from the cam, remove the chain from it, while having the damper on the crank sitting at the zero mark, and rotate both the cam and the cam socket so they are alined with the timing marks, then mark that point and put the timing chain back on I should be relatively close to being at the correct time shouldn't I? I asked 4 different tool places in town while away, none of them had the gauge or even had a clue what I was talking about as far as looking one up... where would I get this gauge?

OP:
I gotta good running 617 I want to get rid of. If you decide that is the answer send me a pm.

Well, I guess my idea was not so great after all.

The tension spring was about worn threw... defiantly not much life left in it. every thing else looked fine. Popped off the cam pulley, turned the cam to line up the timing mark.

Got everything lined up and back together turned it over and the cam shaft broke in 3 places.... I'm calling this engine scrap metal.

Oh well... pain in the ass that I spent all week working on it to rebuild the starter and get the A/c working put in the new glow plugs etc... but whatever. I'll transfer those parts over to my CD's engine.

Now just have to decide to part it out or put another engine in.

That's the definition of epic fail.

Sometimes I wonder why I post on here................:rolleyes:

seriously? I tried at least. I've spent the last 7 days combing for information as to what to try next. The only thing that came close to my issue required engine rebuild. One that cost more that than the whole cars worth. I gave it a shot and it broke. Oh well. No one had the answer. I have 500 bucks and some sweat in the car. I'll make that back on scrapping the body after I part everything else off her. I figured it was in good enough shape to at least try to put it on the road but live and learn.

The interiors absolutely perfect in this car, all the wood work looks new. All the windows work smooth, the sunroof is smooth and there is almost no rust on the car. Plenty left for parts.

You're going to get a reputation as a Nostradamus.

I'm guessing something really was hitting something once the cam was turned.

Why did you think that moving the cam that much on a running engine wouldn't cause some serious maladjustment? Did you turn it over by hand before using the starter?