My 2001 3500 has ALWAYS, had a tendency to do what sounds to me like old fashioned gasoline engine "spark knock" when towing my travel trailer and peaking out at the top of the power curve near the top of a steep grade.

I have asked several other owners if this occured with their truck and they all said no, diesel's don't have spark knock and what I'm hearing must be something else.

But that's sure what it sounds like to me....and it stops the second I let off. I have 55K on the truck, but mileage doesn't seem to be an issue since it has always done it from time to time...doesn't do it "every" time, but often enough.

I don't have any codes showing, or any other issues (that I'm aware of) with the truck.

Always maintained extremely well. Any ideas...?????

I am posting this on the 24 valve section as well.
Thanks
chuck

 

Do you have gauges? what are they reading when this happens? Diesels can suffer from detonation the same as gassers , only it is different , and i don't know enough about it to explain.

 

No...no gauges...
I'm trying to figure out how to install a fuel pressure guage now, but haven't found any good instructions yet.

 

Is it possible that you have a valve that may be out of adjustment? I had a similar type of noise and it was a very out of spec valve.

 

Sounds like a valve out of adjustment, bad injector, or vapor lock similarity, caused by lift pump failure, and inj.pump starving for fuel under high fuel demand. Better check for codes, and fuel pressure soon. Then do a valve set.

 

And install a EGT gauge while you'r at it.... since you are towing you will need it. Floored, I bet your hitting over 1400 degrees.

HoDiesel

 

The way the 24V sounds does change over the rev range. For example, when accelerating with a load in 5th gear (on a 6-spd) I can hear my timing change at around 2300 rpm quite clearly. It engine becomes much more noisy and the detonation sound is much higher pitched.

When I think of knocking in the gasser sense it's a somewhat intermittent sound that doesn't occur at the same rate as cylinder firings. The sound I'm talking about is at the same rate as cylinder firings.

 

Did you check for any codes yet, sounds fuel related.

 

check this out...

http://dodgeram.info/tsb/2002/09-008-02.htm

 

THANKS...! That describes it perfectly....! I will cange the thermostat and see what happens. A cheap easy fix...if it works. You guys are SO SMART...!!!!!

 

If I had an EGT...and the temp was/is 1400 degrees...what can one do...????

 

Now if I can just find out how to keep my signature working...

 

your sig i omitted after the first post in a thread to save space.

 

If your EGT was/is that high all you have to do is to not hold down the accelerator so hard. Ease up on the pedal to bring the EGTs down.