Another what is this sound thread - PeachParts Mercedes-Benz Forum

cmac2012 · #1 05-02-2017, 12:28 PM

Forgive me y'all, probably regular diesel chatter but my 300SDL makes such a damn chatter at start up that it's got me worried. There's a loud rapping that's out of time with everything else.

http://youtu.be/dg-YpksWjyA

Phillytwotank · #2 05-02-2017, 12:52 PM

sounds like normal om60X sounds to me. The"loud rapping that's out of time with everything else" sound you are describing is the sound of the lifters.

kerry · #3 05-02-2017, 12:53 PM

Regular diesel chatter? Have you tried a purge?

greazzer · #4 05-02-2017, 12:58 PM

Sounds a little throaty, but really sounds like an exhaust leak at worst.

cmac2012 · #5 05-02-2017, 02:19 PM

Quote:

Originally Posted by kerry

Regular diesel chatter? Have you tried a purge?

Do you mean something like this?

https://www.youtube.com/watch?v=TFz3Mgc_Tz0

I'm new to this engine and really not highly experienced with diesels period. The engine sounds smoother when it warms up and at speed. I had a lousy feeling that something was going south and that I should record the sound for clues in case it stopped running.

I don't get why lifter noise would be irregular - makes me think that one or two are looser than the others.

kerry · #6 05-02-2017, 02:36 PM

Yes. Purging can quiet down an engine in my experience.

crazy4diesel · #7 05-02-2017, 03:09 PM

Yes, but follow these instructions: https://www.youtube.com/watch?v=8Zpb1dGgwbo&ytbChannel=Lozzy07

The car is a VW TDI, but the process would be the same, I prefer this method because of the filtration of the returning diesel purge. It makes no sense to run that crap right back through your injection system.

Quote:

Originally Posted by cmac2012

Do you mean something like this?

https://www.youtube.com/watch?v=TFz3Mgc_Tz0

I'm new to this engine and really not highly experienced with diesels period. The engine sounds smoother when it warms up and at speed. I had a lousy feeling that something was going south and that I should record the sound for clues in case it stopped running.

I don't get why lifter noise would be irregular - makes me think that one or two are looser than the others.

cmac2012 · #8 05-02-2017, 04:10 PM

Good point and I'll study that vid. I had the same thought, that the dirty stuff was being cycled back through.

cmac2012 · #9 05-02-2017, 04:16 PM

Quote:

Originally Posted by greazzer

Sounds a little throaty, but really sounds like an exhaust leak at worst.

There is a tiny one, couple of spots actually. In an earlier thread I asked what this part was called, turns out it's fabbed EGR delete, well, the delete leg of the recalled particle filter as well.

I just got the rectangular gasket for the attachment to the turbo, haven't put it on yet. I knew it was missing because I had to take it off to get to the final connection to the exhaust pipe. Yesterday I did a soapy water test on the two ends of it, takes a minute for it to get hot enough to boil the water away instantly.

I have small leaks on both ends. The turbo side can be helped by the gasket, not sure about the flare portion. I had a thought to put maybe 16 gauge solid copper wire in a loop around it and see if it would compress down to make a seal.

greazzer · #10 05-03-2017, 06:56 AM

If you can just plug up the holes / leaks on a temp basis to see if that is the sound, then you solved your puzzle. From experience, that throaty sound is exhaust leakage. But then again, older diesel engines make all sorts of noise ... lol

86-300sdl · #11 05-03-2017, 10:53 AM

Get a 1/2 qt of 2 stroke oil or other cetane booster (Walmart stuff) in the tank. Get the motor fully warmed up...take it out for an Italian tune up...and I mean flog it running the gears i.e. 3rd gear mashed to about 4,300 rpm. The smoke will be a little embarrassing when you first beat it. Then it will significantly clear on the second or third pedal mashing.

You'll find when you get back from the flogging the motor will be far quieter.

The diesel purge may also help. I just did my annual 2-can purge and it seems to quiet the chatter down.

Your local fuel supply cetane numbers may be a bit low for the 603.96 motor. I find that raising the fuel cetane with 2-stroke etc calms the chatter. So I run four ounces per fill up.

I generally baby my motor so its a little unnerving for me to go out and flog it. But it likes it!!!

jake12tech · #12 05-03-2017, 11:03 AM

I hear lifter noise, and a regular diesel clatter at cold start. Nothing alarming or to be concerned about. Add some crane booster and call it a day. I'd eventually replace the lifters though.

86-300sdl · #13 05-03-2017, 11:33 AM

Quote:

Originally Posted by cmac2012

Do you mean something like this?

https://www.youtube.com/watch?v=TFz3Mgc_Tz0

I'm new to this engine and really not highly experienced with diesels period. The engine sounds smoother when it warms up and at speed. I had a lousy feeling that something was going south and that I should record the sound for clues in case it stopped running.

I don't get why lifter noise would be irregular - makes me think that one or two are looser than the others.

Your lifters sound fine. They "clack" like hell when bad. Usually kind of transient clacking. Didn't hear a bad one in the vid.

Diesel purge is super easy on the SDL:

Basically buy two cans of lubri-molly diesel purge, buy new inline and canister filters, extra 8" piece of fuel line, and a two qt plastic bottle i.e. Gatorade.

Unplug the IP fuel supply line from the steel supply tank line, so that the inline filter stays in place. Add about an 8" piece of fuel line to the filter and stick it into a plastic jug all the way to the bottom.
Next remove the fuel return hose from the steel fuel return line that runs back to the tank (same area as supply line), and stick the hose into the jug.
Fill your new canister filter with diesel purge and set aside. Almost takes the full can of purge.
Pour the remaining purge into the jug and run the motor until the jug purge level is about an inch. You don't want to draw any air into the line.
Re connect the fuel lines, replacing the inline filter.
Remove the canister filter by removing the bolt from the top center. Remove the bolt (fuel banjo) completely, then pull the filter out. It will have purge in it so pour that back into the gas tank at the filler.
Install new can filter that is loaded with diesel purge. Install new o-ring seals on the "filter bolt". Or-rings supplied with the filter. No need to prime. Motor may initially stumble a little due to some air in line from changing stuff out.

vstech · #14 05-03-2017, 12:33 PM

Quote:

Originally Posted by cmac2012

There is a tiny one, couple of spots actually. In an earlier thread I asked what this part was called, turns out it's fabbed EGR delete, well, the delete leg of the recalled particle filter as well.

I just got the rectangular gasket for the attachment to the turbo, haven't put it on yet. I knew it was missing because I had to take it off to get to the final connection to the exhaust pipe. Yesterday I did a soapy water test on the two ends of it, takes a minute for it to get hot enough to boil the water away instantly.

I have small leaks on both ends. The turbo side can be helped by the gasket, not sure about the flare portion. I had a thought to put maybe 16 gauge solid copper wire in a loop around it and see if it would compress down to make a seal.

Check your vin...

That isn't the factory delete...

Yours may be qualified for a cast iron factory delete and turbo free replacement!

Check with a dealer...