clacking from cyl #1 in a 606 - PeachParts Mercedes-Benz Forum

cazmont · #1 08-30-2009, 08:27 PM

Hi, I looked for a thread covering my issue without luck so I'm hoping either to be directed to it or we'll start a new one.
In any case....I took a few measures to resolve rough idle and noise issues with my 95 124 606 and resolved some of the problems. The engine runs very well, good power, decent fuel consumption and a decent idle. However the noise issue continues. It consists of loud clanking at cold start up in the morning that diminishes quickly, within 2 minutes, to a constant clatter.

By cracking the fuel lines I found the noise to be definitely coming from no. 1 cylinder. To check the injector I swapped cylinder injectors and the noise stayed at no. 1.

Suspecting a clogged pre combustion chamber I cleaned it out with chemicals, vacuuming and compressed air. It may currently be the cleanest PCC in existence. If anything, the noise has increased though the engine continues to function well.

Suspecting a possible wristpin issue I very slowly increased engine speed in neutral and noticed a decrease in sound AND frequency of the sound as engine speed increased.

Again the engine runs well, no smoke, idle a little rougher than a gasser but the sound does not seem healthy and is only coming from no. 1.

I got some great responses on my tuned induction adventure and am hoping for the same from the forum. Thanks, Jack

79Mercy · #2 08-30-2009, 10:04 PM

After I cleaned my injector nozzles in my 76 300D the engine was a lot louder when started cold. But after about 100-200 miles it started to sound normal when cold. My mechanic said it was normal because the injectors were clean.

lietuviai · #3 08-30-2009, 10:23 PM

I'm thinking you may have something going on in the valve train. I looked in the FSM and there are hydraulic valve clearance compensating elements. I'm not familiar with their operation in the 606 engine but I've seen something similar in a Toyota engine. If they are worn out or their oil passages get gummed up they can loose their ability to provide the correct clearance at low idle. Increasing idle possibly gets more oil flowing in them reducing the noise.

TMAllison · #4 08-31-2009, 12:00 AM

Whats your mileage?

Any weeping fuel on top if the IP at #1's DV?

cazmont · #5 08-31-2009, 01:52 AM

Hi to all, thanks for the responses. I should have noted that the car has almost 100k on it. The IP was replaced at about 60k. I've put about 30K on the car in the last 4ish years. I'm a pretty experienced gas wrencher but this is my first diesel. I'm pretty on top of this cars maintenance but my impression is that this noise has been slowly increasing and I haven't noticed it until recently due to my diesel inexperience.

That said, I believe the hydraulic lifters are ok. They appear to be typical of gas lifters from what documentation of them I've seen. Also, no leakage at the delivery valve area atop the IP. FYI there are keepers that lock down the spline type nuts housing the delivery valves on this vintage IP so all should be well there. I'm leaning towards IP timing check? I have some documentation of the little past (pre me) maintenance and it is possible that no check of the IP timing has occurred in almost 40k. Is now the time and could this be related to my noise issue. I doubt if much timing chain stretch has occurred. The sounds coming from the opened oil filler are very healthy and the overall impression from this engine is of strength and vitality!

KarTek · #6 08-31-2009, 05:58 AM

My 606 has a bad injector (poor spray pattern) and it clacks from the #5 pot. I found this when I pulled the injector and pop tested it.

Maybe you can have a local shop do the same and observe the spray pattern. Shouldn't cost too much.

cazmont · #7 08-31-2009, 12:40 PM

Thanks Evan. Since I've swapped injectors without the noise moving away from cylinder one I don't think we're talking injectors here. I've read elsewhere that there is a relationship between IP function and noise occurring at the no. 1 cylinder but didn't understand what that was. Doing some more reading today.

KarTek · #8 08-31-2009, 01:12 PM

OK, yeah, improper torque on the delivery valves can really cause some screwy behavior.

WINGAS · #9 08-31-2009, 02:04 PM

Well, I had the same issues it was a compression problem.

cazmont · #10 09-14-2009, 06:58 PM

Only fair to post my mistakes and failures with successes. Specially when they both occur at the same time. After tearing into the injectors and clean clean cleaning everything I tested or could get my hands on it was time to realize I was not dealing with an injector/timing issue. At the beginning of the process my wife did some research and reported in that it was the glow plug on cylinder 1 which I immediately dismissed. I figured the glow plug circuit shut down pretty quickly after start up and my issues continued well after that. Wrong. I finally got around to checking the glow plug wiring connectors and one was loose. Yeah, the glow plug on no. 1 cylinder. Sheeesh. Engine runs great now. I know a lot more about diesels coming out than going in so it wasn't a complete waste of time. Thanks for the suggestions.

tankowner · #11 09-14-2009, 09:09 PM

Quote:

Originally Posted by cazmont

At the beginning of the process my wife did some research and reported in that it was the glow plug on cylinder 1 which I immediately dismissed. I finally got around to checking the glow plug wiring connectors and one was loose. Yeah, the glow plug on no. 1 cylinder. Sheeesh.

So the question is, will she ever let you live this one down??? Would she be willing to spend some time on here diagnosing my 95's problems?

I have actually had some (what sounds to be excessive) clacking for a while. Like you, I have always believed that I just need to rebuilld my injectors. Interestingly enough, it has recently begun to miss a little (very briefly) on start-up. I am now of the mind that I have some plugs that are on their way out. Once I get the 240d on the road (hopefully by the end of the month), I plan to replace the plugs - looking forward to that one.

cazmont · #12 09-15-2009, 01:04 AM

Oh I'll soon have a new issue to be straightened out on and this will all be forgotten. Send me a line and I'll see what she says.
I changed out the glow plugs 15k ago and it wasn't much trouble at all. The intake plumbing comes off easily and there they are.

connerm · #13 09-15-2009, 06:07 AM

Quote:

Originally Posted by cazmont

The intake plumbing comes off easily and there they are.

Please advise on how you do this easily. Removing the x-over stuff is a real pain.

lupin..the..3rd · #14 09-15-2009, 11:45 AM

Quote:

Originally Posted by cazmont

At the beginning of the process my wife did some research and reported in that it was the glow plug on cylinder 1 which I immediately dismissed. I figured the glow plug circuit shut down pretty quickly after start up and my issues continued well after that. Wrong. I finally got around to checking the glow plug wiring connectors and one was loose. Yeah, the glow plug on no. 1 cylinder. Sheeesh. Engine runs great now.

LMAO great story!

Diesel911 · #15 09-15-2009, 12:42 PM

Quote:

Originally Posted by tankowner

So the question is, will she ever let you live this one down??? Would she be willing to spend some time on here diagnosing my 95's problems?

I have actually had some (what sounds to be excessive) clacking for a while. Like you, I have always believed that I just need to rebuilld my injectors. Interestingly enough, it has recently begun to miss a little (very briefly) on start-up. I am now of the mind that I have some plugs that are on their way out. Once I get the 240d on the road (hopefully by the end of the month), I plan to replace the plugs - looking forward to that one.

A long thread; but, note in the below thread how he had a lot of Air leaks to deal with. This is if the noise is a fuel injection/fuel supply issue.
http://www.peachparts.com/shopforum/showthread.php?t=256999