[nitroman]

I'm hearing engine knocking while pulling 8000 lb trailer, especially going up hills. As I approach the top of the hill and ease off the throttle the knocking gets a bit quicker. Any ideas?

 

[JDiepstra]

Do you have any modifications on your truck? Running any chips, tuners, programmers, or anything like that? Sounds like it could be timing rattle which can be caused by tuners that advance timing very aggressively in order to increase mpg's.

 

[nitroman]

no mods

no modifications

 

[dwphello]

Knock Knock

Does it only do it under a load?

You may have galled up a piston because of a semi plugged up piston cooler nozzle.

What kind of oil filter you running?

 

[dirtbike375]

check for exhaust leaks too, they cause a "knocking" type of noise

 

[nitroman]

It's worse under a load, but does it without a load too. Took it to dealer and drove it around with a tech...he acted like it was normal and they all make this noise. (just bought a month ago and it's my first diesel.) Also, they said they changed the oil, but it's very black. Is that normal after only a few hundred miles.

 

[kd5jha]

Read This

I did not think that dodge wanted you to tow anything super heavy for the fist 3000 miles or so.?.

They say in the manual on my 2003 cummins that they want you to tow moderate or no loads for the first so many miles...I can't remember exactly how many, but you might hold off on towing 8000lb+ loads up steep hills till you get 5000 or so miles on this truck just to be safe.

RMG

 

[nitroman]

It's a 2004 3500 w/ 25000 miles.

 

[dbcooper]

You may want to compare it to another truck at idle. diesel has a rattle sound that is - i guess you could say normal or natural or something.

also when cresting a hill or rapid desceleration after being under load you may hear your wastegate. it releases the pressure from the turbo in advance of the engine, when it is necessary. the sound from this usually gets more pronounced after a mod- do to a much higher psi

as an experiment try accellerating rapidly, and at the upper end before it flattens out try decelerating rapidly. at just that moment when you press the brake, ( no need to try and stop on any change, just decelerate.) pay attention to the sounds you hear and try to determine if the noise at the moment your rpm drops is the one you are asking about.

if so it is possible that you are hearing standard engine sounds and the wastegate allowing you a controlled deceleration.

:thumbsup:

Don't worry too much yet - diesels are loud, probably part of why you bought one.

 

[nitroman]

Thanks for the reply. I think Ive heard the wastegate...more of a whistling type noise. This noise is a knock more like a gas engine knock where timing is off or gas needs more octane.

 

[fl dodge]

Thanks for the reply. I think Ive heard the wastegate...more of a whistling type noise. This noise is a knock more like a gas engine knock where timing is off or gas needs more octane.

i have the very same thing going on i had it back to the dealer twice for this knock , they said they could easily hear it but they could not pin point it they thought for sure it was a rocker shaft but when they checked them everything was right on spec. they checked push rods ,injecters,turbo and they still could not locate it .they said if or when the knock changes to come back in.this knock is starting to drive me crazy does anyone have any ideas about this?????

 

[ss47]

Thats funny my owners manual actually suggest towing upto @ 10,000lbs for the first 500 mi? it says engine will break in sooner and perform better.

 

[nitroman]

i have the very same thing going on i had it back to the dealer twice for this knock , they said they could easily hear it but they could not pin point it they thought for sure it was a rocker shaft but when they checked them everything was right on spec. they checked push rods ,injecters,turbo and they still could not locate it .they said if or when the knock changes to come back in.this knock is starting to drive me crazy does anyone have any ideas about this?????

Does yours knock at idle or just going up slight grades or even worse on big hill? (not knock at idle for me.) This is my 1st diesel and not sure if I'm just hearing a normal diesel sound and being paranoid. Am I correct that there should be no knocking whatsoever? Drove around with tech at Dodge dealer and he says it's was normal. Doesn't sound normal to me though. I wonder if I could find a good diesel mechanic and pay him to listen to it for me? (Even though I would have to go back to Dodge because I still have a little time left on my warranty.)