1983 300D Engine Knock - Page 3 - PeachParts Mercedes-Benz Forum

Air&Road · #31 01-25-2016, 06:56 AM

Those tools are much cheaper now than when I bought them in the nineties.

funola · #32 01-25-2016, 08:43 AM

Try glowing the plugs and see if that lights up the pre-chamber enough to see the ball pin.
If not or if the glow plug is occluding the ball pin, take the glow plug out and use a flashlight. Make an L hook out of a coat hanger and feel if the ball pin is loose.

jcoop · #33 01-25-2016, 10:49 AM

Quote:

Originally Posted by funola

Try glowing the plugs and see if that lights up the pre-chamber enough to see the ball pin.
If not or if the glow plug is occluding the ball pin, take the glow plug out and use a flashlight. Make an L hook out of a coat hanger and feel if the ball pin is loose.

That's a really good idea, I'll have to give that try next time im in the garage.

Quote:

Originally Posted by vstech

I'd spray some pb blaster in there then some brake spray and take another picture. it looks like i see the ball in one of the pics.

That's also a good idea. Is the ball pin big or small? I feel like it would be fairly obvious yet it's hard to see being so coked up with soot.

Quote:

Originally Posted by charmalu

You will need two tools to remove the Lock Ring first and one to pull the Pre-Chamber.

The Lock Ring is easy.
The Pre-Chamber will take some work with a Slide Hammer. I have pulled a bunch of them in the yards.

The Pre-Chambers take 15 - 25 whacks on the hammer.

This first one is for the Lock Ring.

Pelican Parts.com - Threaded Pin Wrench Socket for prechamber in cylinder head

The next one is for the Pre-Chamber.

Pelican Parts.com - Extractor Tip for prechamber in cylinder head

There is a bicycle tool for pulling the crank, brand is a parker tool. For around $15, that can be adapted to the
Slide Hammer. Most bike shops will have it.

http://www.peachparts.com/shopforum/1590182-post9.html

http://www.peachparts.com/shopforum/diesel-discussion/207782-diy-617-9xx-prechamber-tools.html

Charlie

Oh wow, excellent resources. Thanks so much! I thought about getting the lock-ring removal tool from **************; it's like $65? However, I will probably make my own chamber removal tool from the bike spindle removal tool. Also, I guess i'll have to get one of the used chambers from ************** since I really have no idea where else to get one? That's supposing mine is bad, of course

Maxbumpo · #34 01-25-2016, 11:23 AM

Quote:

Originally Posted by jcoop

And this is the inside of #4 collar. I feel like the milky-fluid shouldn't be in there. What do you guys think? I guess I need to get the proper collar removal tool to get a better peer into the pre-chamber for bits of material.

That milky fluid looks to me like it was on the outside of the injector and flowed down into the hole after you pulled the injector. Maybe just dirty water? Carefully clean it out and then keep an eye out for leaks in that area, but I don't think that is an issue.

jcoop · #35 01-25-2016, 12:17 PM

Quote:

Originally Posted by Maxbumpo

That milky fluid looks to me like it was on the outside of the injector and flowed down into the hole after you pulled the injector. Maybe just dirty water? Carefully clean it out and then keep an eye out for leaks in that area, but I don't think that is an issue.

That's definitely not a bad thought. Unfortunately, I don't think that was the case... Everything was dry and (fairly) clean when I started. Is it at all possible for that heat shield to have been leaking and allowing fuel to slip past, pooling in the area? Seems like a long-shot, though.

funola · #36 01-25-2016, 12:57 PM

Best pre chamber ball pics: http://www.peachparts.com/shopforum/diesel-discussion/368004-prechamber-ball-2.html

jcoop · #37 01-25-2016, 10:22 PM

Quote:

Originally Posted by funola

Best pre chamber ball pics: http://www.peachparts.com/shopforum/diesel-discussion/368004-prechamber-ball-2.html

Holy crap! Thanks so much for sharing that thread... I ended up reading the whole thing and learned quite a bit in the process. Well, at least i know what i'm looking for at this point. I hope the inside of my engine doesn't look like that

mach4 · #38 01-26-2016, 11:38 AM

Quote:

Originally Posted by jcoop

Holy crap! Thanks so much for sharing that thread... I hope the inside of my engine doesn't look like that

I hope so too!

kestreltom · #39 01-26-2016, 01:19 PM

Quote:

Originally Posted by charmalu

You will need two tools to remove the Lock Ring first and one to pull the Pre-Chamber...
Charlie

and don't forget to pull the glowplugs first

also: keep in mind that the PO might not have replaced the cam timing chain tensioner spring when he did the timing chain. A broken tensioner spring is relatively easy to check and fix - and might explain the erratic noise.

jcoop · #40 01-26-2016, 09:08 PM

So, I had a few extra minutes before work, so I went ahead and checked the 'ball-situation' in the pre-chambers. AAAANNNNNDDD as it turns out, they're all there and doing what they should be. Soooo, back to the drawing board.... I may go ahead and swap the injectors out/around and see what happens with that. Also, i'm going to check the timing chain tension-er. I have to say... i'm not exactly heartbroken I don't have to pull the chambers...

barry12345 · #41 01-27-2016, 02:14 PM

I reviewed the thread again including watching the video again. Before moving on I would loosen the suspect cylinders hard lines one at a time. Rev the engine a little and see if the noise is still present. I suspect it will remain but is not really conclusive of anything.

If you have the opportunity to contact the person you purchased the car from. Do so.

You want to know if the noise was present right after the timing chain change. Or when it first appeared. If right after the timing chain change there are two possibilities in my mind.

The cam timing in relation to the crank is out. Or when the cam sprocket was removed a washer was left out allowing the cam to develop a back and forth shuttle. You might inspect for that washers presence. I hear it is very easy to drop that washer into the void. If the guy doing the chain had not done many of these cars it is possible he might have missed this. I think these engines have that washer. The out of time cam is less likely than the washer missing. Although it might be a light valve contact we are hearing.

I dislike mentioning this but in my limited experience if something new occurs right after a repair. Or I know there was something reciently done and now there is a new issue. That is the logical starting area.

At the same time I am not a working mechanic and have limited knowledge. So when I mention something it should be weighed carefully. As it is purely an amateurs opinion.

To me your noise is and remains a little strange. At idle the engine sounds very solid. I also am trying not to lead you down paths that may not be productive.

I do not think I would drive that car until whatever is found as the cause is established. Something could get damaged.

I figured you would be happy to find you still have your balls in good condition as you did.

jcoop · #42 01-27-2016, 07:43 PM

Quote:

Originally Posted by barry12345

I reviewed the thread again including watching the video again. Before moving on I would loosen the suspect cylinders hard lines one at a time. Rev the engine a little and see if the noise is still present. I suspect it will remain but is not really conclusive of anything.

If you have the opportunity to contact the person you purchased the car from. Do so.

You want to know if the noise was present right after the timing chain change. Or when it first appeared. If right after the timing chain change there are two possibilities in my mind.

The cam timing in relation to the crank is out. Or when the cam sprocket was removed a washer was left out allowing the cam to develop a back and forth shuttle. You might inspect for that washers presence. I hear it is very easy to drop that washer into the void. If the guy doing the chain had not done many of these cars it is possible he might have missed this. I think these engines have that washer. The out of time cam is less likely than the washer missing. Although it might be a light valve contact we are hearing.

I dislike mentioning this but in my limited experience if something new occurs right after a repair. Or I know there was something reciently done and now there is a new issue. That is the logical starting area.

At the same time I am not a working mechanic and have limited knowledge. So when I mention something it should be weighed carefully. As it is purely an amateurs opinion.

To me your noise is and remains a little strange. At idle the engine sounds very solid. I also am trying not to lead you down paths that may not be productive.

I do not think I would drive that car until whatever is found as the cause is established. Something could get damaged.

I figured you would be happy to find you still have your balls in good condition as you did.

I put the engine back together this evening and started it up... Of course nothing changed, so i swapped out #3 and #4 injector with two old Bosch re-man's that i had laying around. The engine really ran quite well; started easy, revved properly and was smooth, but the pingy knock was still there. Interestingly, it sounds like it is coming from the timing chain area. Initially, I think there were a couple different things at play when it came to the noise. It seems reduced but is still there.

So, once it cooled off a bit, I was curious about the chain tensioner (as mentioned by another user). So, I took the bolt off and out popped a perfectly in-tact spring. AGH. Back to the drawing board yet again.

I still haven't checked the vacuum pump, however...

Alec300SD · #43 01-27-2016, 09:08 PM

I think barry12345 is onto something.

Fore and aft movement of the camshaft can cause the type of "clack" that you are hearing.

Oilslick reported a similar problem in this thread.

http://www.peachparts.com/shopforum/diesel-discussion/368330-camshaft-play-om602.html

Remove the oil cap and take a look at the cam for any fore and aft movement while the engine is running.

If you see fore and aft movement of the camshaft, that half moon cam key may have fallen out (or not been re-inserted) during reassembly when prior work was done.

Good luck in resolving your problem.

jcoop · #44 01-27-2016, 10:13 PM

Quote:

Originally Posted by Alec300SD

I think barry12345 is onto something.

Fore and aft movement of the camshaft can cause the type of "clack" that you are hearing.

Oilslick reported a similar problem in this thread.

http://www.peachparts.com/shopforum/diesel-discussion/368330-camshaft-play-om602.html

Remove the oil cap and take a look at the cam for any fore and aft movement while the engine is running.

If you see fore and aft movement of the camshaft, that half moon cam key may have fallen out (or not been re-inserted) during reassembly when prior work was done.

Good luck in resolving your problem.

Oh that's really interesting... Gah, reading this forum just makes me want to go back out to the garage and fiddle with my car! After watching oilslick's video, that really sounds like the knock my car is producing...

Thanks so much for sharing that... I'm quite eager to get out there and see if that's it or not..

So, supposing that is it.. what do ya'll reccommend my first course of action be? I've never had the top end of an OM617 apart before and really don't want to finish-off a salvageable engine

barry12345 · #45 01-28-2016, 02:55 PM

Slow and easy. You should not damage anything. Always remember though that when working in the chain area to always stuff enough rags in to catch anything that drops accidentally.

I do not know much but the poster suggesting that observation of the cam through the oil filler cap was a decent ideal. My only problem is if you can visually pick up any shuttle when you rev the engine into the noise area. Still an excellent starting point.

Another thing I also found strange or at least to me. The idle sound was almost too good to have two injectors that bad. No particular signifigance but not to be forgotten totally either.

You might want to post a new video with the reduced noise. A more astute member than me. And there are a pile of them. May have a better chance of identification then. Or generate more helpful approaches. Personally I suspect you are more likely to find this problem than not anyways.