OM616 crackling sound under load in low/mid RPMs
OM616 crackling sound under load in low/mid RPMs
To produce the noise:
-RPMs in the low-mid to mid range (no tach on the 240D, sorry)
-Under medium load - don't have to go WOT but do need to be giving it some pedal, on flat ground.
-Not speed related - happens under similar loads and RPMs in all gears
The noise itself:
-Sharp crackle, like whacking a piece of walnut against a steel block
-Random pattern - not directly related to RPM of the engine, like dropping water into a hot pan of lard
-Can't quite tell where it's coming from, other than engine bay, and can't really pinpoint as it only happens under load and not standing still in the same RPM range.
I recently did a valve adjustment and it has been driven at least a couple thousand miles between the adjustment and when the noise started. Oil and coolant levels are good with good fluid in both. Engine is running warmer than I'd like but not overheating, and the noise happens on everything from a cold start to fully warmed up.
Any ideas? Start replacing parts until it goes away?
If I nobody has ideas, my course of action will likely be, in this order, until the problem goes away:
-Do diesel purge
-Replace both fuel filters
-Inspect timing
-Inspect timing chain
-Check IP timing, correct if necessary
-Do another valve adjustment
-Inspect injectors and prechambers for visually evident damage, R&R prechambers if damaged
-New injector nozzles / rebuild injectors
I'm not sure what to make of it, I originally thought maybe something was rattling around but I can't locate anything in the engine bay that would do it, and the conditions to reproduce it seem to be engine related.
To produce the noise:
-RPMs in the low-mid to mid range (no tach on the 240D, sorry)
-Under medium load - don't have to go WOT but do need to be giving it some pedal, on flat ground.
-Not speed related - happens under similar loads and RPMs in all gears
The noise itself:
-Sharp crackle, like whacking a piece of walnut against a steel block
-Random pattern - not directly related to RPM of the engine, like dropping water into a hot pan of lard
-Can't quite tell where it's coming from, other than engine bay, and can't really pinpoint as it only happens under load and not standing still in the same RPM range.
I recently did a valve adjustment and it has been driven at least a couple thousand miles between the adjustment and when the noise started. Oil and coolant levels are good with good fluid in both. Engine is running warmer than I'd like but not overheating, and the noise happens on everything from a cold start to fully warmed up.
Any ideas? Start replacing parts until it goes away?
If I nobody has ideas, my course of action will likely be, in this order, until the problem goes away:
-Do diesel purge
-Replace both fuel filters
-Inspect timing
-Inspect timing chain
-Check IP timing, correct if necessary
-Do another valve adjustment
-Inspect injectors and prechambers for visually evident damage, R&R prechambers if damaged
-New injector nozzles / rebuild injectors
---------------------------------
daily driver
w115 240d 72hp 3.07 rearend
w123 om602 turbo 200whp 7.5mm pump fivespeed 3.07 rearend
+ a few more.
mbturbo.com
swampmonkey
05-16-2014, 06:24 AM #2id say its the chain.... it will probably live for a long time.. but still, its a sign
---------------------------------
daily driver
w115 240d 72hp 3.07 rearend
w123 om602 turbo 200whp 7.5mm pump fivespeed 3.07 rearend
+ a few more.
mbturbo.com
And last but not least; could you record the noise?
But my first suspicion would be air or worn injectors...
DiseaselWeasel
05-18-2014, 05:29 AM #4Oh cheeses... Do you have air bubbles in the fuel lines going to the filter? Have you had the injectors tested? Pump timing?
And last but not least; could you record the noise?
But my first suspicion would be air or worn injectors...
(05-16-2014, 05:50 AM)stan I'm not sure what to make of it, I originally thought maybe something was rattling around but I can't locate anything in the engine bay that would do it, and the conditions to reproduce it seem to be engine related.
To produce the noise:
-RPMs in the low-mid to mid range (no tach on the 240D, sorry)
-Under medium load - don't have to go WOT but do need to be giving it some pedal, on flat ground.
-Not speed related - happens under similar loads and RPMs in all gears
The noise itself:
-Sharp crackle, like whacking a piece of walnut against a steel block
-Random pattern - not directly related to RPM of the engine, like dropping water into a hot pan of lard
-Can't quite tell where it's coming from, other than engine bay, and can't really pinpoint as it only happens under load and not standing still in the same RPM range.
I recently did a valve adjustment and it has been driven at least a couple thousand miles between the adjustment and when the noise started. Oil and coolant levels are good with good fluid in both. Engine is running warmer than I'd like but not overheating, and the noise happens on everything from a cold start to fully warmed up.
Any ideas? Start replacing parts until it goes away?
If I nobody has ideas, my course of action will likely be, in this order, until the problem goes away:
-Do diesel purge
-Replace both fuel filters
-Inspect timing
-Inspect timing chain
-Check IP timing, correct if necessary
-Do another valve adjustment
-Inspect injectors and prechambers for visually evident damage, R&R prechambers if damaged
-New injector nozzles / rebuild injectors
Austincarnut
05-18-2014, 10:48 AM #5can you record the noise for us to hear, it may be the fastest and cheapest way to go
(05-16-2014, 05:50 AM)stan I'm not sure what to make of it, I originally thought maybe something was rattling around but I can't locate anything in the engine bay that would do it, and the conditions to reproduce it seem to be engine related.
To produce the noise:
-RPMs in the low-mid to mid range (no tach on the 240D, sorry)
-Under medium load - don't have to go WOT but do need to be giving it some pedal, on flat ground.
-Not speed related - happens under similar loads and RPMs in all gears
The noise itself:
-Sharp crackle, like whacking a piece of walnut against a steel block
-Random pattern - not directly related to RPM of the engine, like dropping water into a hot pan of lard
-Can't quite tell where it's coming from, other than engine bay, and can't really pinpoint as it only happens under load and not standing still in the same RPM range.
I recently did a valve adjustment and it has been driven at least a couple thousand miles between the adjustment and when the noise started. Oil and coolant levels are good with good fluid in both. Engine is running warmer than I'd like but not overheating, and the noise happens on everything from a cold start to fully warmed up.
Any ideas? Start replacing parts until it goes away?
If I nobody has ideas, my course of action will likely be, in this order, until the problem goes away:
-Do diesel purge
-Replace both fuel filters
-Inspect timing
-Inspect timing chain
-Check IP timing, correct if necessary
-Do another valve adjustment
-Inspect injectors and prechambers for visually evident damage, R&R prechambers if damaged
-New injector nozzles / rebuild injectors
here's a video of the noise. really prominent at about 17 secondsunknown engine noise: http://youtu.be/fZDMPRdEDms
(07-01-2014, 06:58 PM)stan here's a video of the noise. really prominent at about 17 secondsunknown engine noise: http://youtu.be/fZDMPRdEDms
Austincarnut
07-01-2014, 07:29 PM #8its marked as private
(07-01-2014, 06:58 PM)stan here's a video of the noise. really prominent at about 17 secondsunknown engine noise: http://youtu.be/fZDMPRdEDms
(07-01-2014, 08:07 PM)stan fixed now
Austincarnut
07-01-2014, 09:29 PM #10can you get it to happen at a standstill? powerbraking...have you tried a stethoscope at all to pinpoint it?
(07-01-2014, 08:07 PM)stan fixed now
(07-01-2014, 09:29 PM)Austincarnut can you get it to happen at a standstill? powerbraking...have you tried a stethoscope at all to pinpoint it?
(07-01-2014, 08:07 PM)stan fixed now
I'm tracking ya. I'd wanna make sure that wasn't emanating from inside the motor, too. If you can reproduce that same sound while power-braking, shut it down and figure it out.
OT, but that's the sound I imagined would accompany the destruction of my 603's vacuum pump at low speed if it were to happen. Before I swapped in the updated version, I straight gambled for those first 8k miles. Troubleshooting a myriad of sounds on my first turbo-six was quite the journey as all ended up unrelated to the pump. Finally chickened out and plunked down dem dollars. Original pump came out looking brand new tho!
Not trying to put a scare in ya, but you describe crackling where I could swear I hear ball bearings dancing around somewhere. That's never a good thing. I would recommend not getting that up to speed. Can you tell if from front or rear of vehicle? While driving if you turn your head 90deg., better yet get a helper to turn head so one ear pointing forward and one rearward.
It is a strange enough sound though. Would be quite funny though if it were just a heat shield dragging on the ground or some such. LOL
MBZ123
(07-01-2014, 09:29 PM)Austincarnut can you get it to happen at a standstill? powerbraking...have you tried a stethoscope at all to pinpoint it?
(07-01-2014, 08:07 PM)stan fixed now
I'm tracking ya. I'd wanna make sure that wasn't emanating from inside the motor, too. If you can reproduce that same sound while power-braking, shut it down and figure it out.
OT, but that's the sound I imagined would accompany the destruction of my 603's vacuum pump at low speed if it were to happen. Before I swapped in the updated version, I straight gambled for those first 8k miles. Troubleshooting a myriad of sounds on my first turbo-six was quite the journey as all ended up unrelated to the pump. Finally chickened out and plunked down dem dollars. Original pump came out looking brand new tho!
Not trying to put a scare in ya, but you describe crackling where I could swear I hear ball bearings dancing around somewhere. That's never a good thing. I would recommend not getting that up to speed. Can you tell if from front or rear of vehicle? While driving if you turn your head 90deg., better yet get a helper to turn head so one ear pointing forward and one rearward.
It is a strange enough sound though. Would be quite funny though if it were just a heat shield dragging on the ground or some such. LOL
MBZ123
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