Peculiar mechanical noises. Sound file attached. - PeachParts Mercedes-Benz Forum

DslBnz · #1 11-23-2005, 05:55 PM

What does this sound like to you?

http://media.putfile.com/350-Klock

I call it the 350 "Klock".

DslBnz · #2 11-23-2005, 06:01 PM

I recorded this using a digicam and 5/16th's rubber hose below the #1 cylinder for sound amplification.

(last time I edit my posts, I promise!)

dmorrison · #3 11-24-2005, 01:16 AM

It could be quite a few things.
My first thought is the the vacuum pump. Since your tube was near the #1 cylinder. You can pull it and visually inspect it. Make sure the ball bearing assembly and levers are sound.

Other considerations are the cam lobes. But I think that would be continuous, not intermittent as it was.

What is the compression on the #1 cylinder. The piston could be slapping the cylinder wall, had this on the 300SDL.

What is the condition of the valve adjustment, when was the last time is was done. Again not convinced about this one, not a continuous noise.

Again, I would start with the vacuum pump.
Get the gasket, pull the unit and look so see if the lever assembly is sound.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1O302NZZC1O302O452&year=1983&make=MB&model=300-DT-001&category=All&part=Diesel+Vacuum+Pump

Dave

Larry Delor · #4 11-24-2005, 09:33 AM

Sounds like my 300D used to. Then, I added a gallon of filtered wvo, and not only did the "klocking" go away, it idled smoother in general.

If you're not up to trying vwo, them how about a quart or two of transmission fluid? It's worth a try, I think.

DslBnz · #5 11-24-2005, 12:21 PM

I call it the 350 Klock because, it is of my 350SD. Compression is nill in cylinder #1. I have a problem recording the metallic clanging underneath the injector(positioning the hose is difficult while holding camera and other end of hose to the mic), but it gets worse when I rev the engine. You can hear the metallic clanging more robustly in the last few seconds of the recording.

I will try for a better recording tomorrow.

I kept altering the position of the hose, THAT'S why it was intermittent.

dkveuro · #6 11-24-2005, 01:05 PM

1987 300SDL had same noise.
Was #5 cylinder piston. Rings had siezed in piston lands and bore was scored.

The noise is piston rock at TDC on compression stroke....piston is knocking against cylinder wall.

If you remove the injector and idle it again, the noise will have gone away.

.

Johnhef · #7 11-24-2005, 10:12 PM

Hows your chain stretch? I had a 602 a few weeks ago that sounded a lot like that. Its chain was stretched 5 degrees. New chain kept the idle smooth and quiet.

t walgamuth · #8 11-24-2005, 10:21 PM

nil compression in #1, i would advise not driving it. i can think of no scenario excpet tight valves which would be ok to keep driving it. have you checked the valves?

the one fellow who said piston rock sounded pretty sure about it. if so that would jive with the no compression thing.

does it use a lot of oil? smoke?

maybe has the dreaded bent rod.

tom w

DslBnz · #9 11-24-2005, 11:55 PM

Quote:

Originally Posted by t walgamuth

"maybe has the dreaded bent rod.

tom w"

I believe so. Something is causing that metallic CLANG CLANG CLANG (more emphatic when you press the hose end to your ear). The car is off the road. Not wanting to risk any further damage, and certainly trying to avoid much humiliation.

I may consider a used 3.0 liter replacement, if necessary(which I'm pretty sure it is). If I get around to it.

dmorrison · #10 11-25-2005, 02:01 AM

Should have posted the zero compression test on #1 cylinder in your first post. That definately means that the #1 piston is slaping the cylinder wall. I had the #1 piston and ring assembly replaced at 150,000 miles, on the SDL, and it went for 100,000 miles before it started again. Pull the head and drop the oil pan to replace the #1 piston/ring assembly. Of course check for a bent rod and blown head while you have the top and bottom open.
I had about 250PSI compression when we did the work. With zero compression I would suspect more of a problem.

Dave

KDHBenz · #11 11-25-2005, 02:28 AM

BTW dmorrison, the pump is significantly cheaper at TheBenzBin.com (P/N: D3000-56042, $303.10)...

dkveuro · #12 11-25-2005, 10:03 PM

Just an FWIW.....
Bent rod will not show up as no compression but as low compression ...commonly around 150 to 200 psi. Bent rod does not always knock either, unless bend is axial and loads the piston/rod journal to one side.

.

turbodiesel · #13 11-25-2005, 10:35 PM

Sounds like injector knock too.

t walgamuth · #14 11-25-2005, 10:56 PM

eventually it would be no compression, i would think

tom w

Sveinn · #15 09-09-2014, 01:08 AM

I know that this post is 9 years old, but why didn't anyone tell the person with the problem that putting transmission fluid in their fuel would cause the vehicle to smoke so much that they couldn't even drive it.

I don't think that it is funny to provide bad information to the ignorant. I think that it is evil to stand by, write nothing and allow a jerk to do this to a newbie.

I am referring to this post:

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Sounds like my 300D used to. Then, I added a gallon of filtered wvo, and not only did the "klocking" go away, it idled smoother in general.

If you're not up to trying vwo, them how about a quart or two of transmission fluid? It's worth a try, I think.
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