At low rpm, starting out from a stop, the engines rattles or koncks. Sounds like a gasser with bad gas/valves knocking. As soon as rpms come above about 1000 it runs fine. She took truck to dealer but not able to diagnos(sp) after about 3 hours of troubleshooting. Dealer is going to contact Cummins for assistance. Any ideas? Does this all the time with or with out trailer. 03 2500 w/auto tranny

 

Check under the hood. I think you might have a diesel engine in there.

Sorry...couldn't resist. ;D

 

Not my truck, I told her the same thing this weekend . She is worried about dealer taking advantage of her being a female (careful with wording there). I drove and there is something wrong

 

Sounds like bad fuel or bad oil. Could be both or not just warmed up good enough. Mine does the same thing if the oil is not warmed up prior to pulling off
Oh, yeah it is a diesel

 

I need to send this link to her so she get the abuse first hand. Problem there even when warmed up, it has been over 100 degrees here until this past weekend. She asked me to park trailer after 3 hours of towing and I noticed then.

 

people have NAY SAYED this statement but AZ (which is where you are at????) has a different batch of fuel going thru there...TWICE in the last month I have picked up fuel in AZ and mine knocks off of idle like no tommorow...the firstime i stopped and checked my oil to make sure all was well...flame on guys but there is something in az fuel that is different...
Cameron

 

ck1--This gal is my wifes best friend and she/I appreciate the advice on the fuel. I know she has been buying somewhere in S. Phoenix cuz its cheap and she is down there a couple times a week. I will suggest she try spending extra few nickels per gallon and try another supplier. I buy on the North side of town and have not had any problems. Thanks

 

...and for the record.....when I got home to California and refueled...no knock...

 

Ummm, might be a great opportunity to try a fuel additive and let us know the gains! Mebbe change out the fuel filter too?

 

Fuel filter changed, trying new fuel today, different supplier will see how it works.

 

Almost sound like the timing is too far advanced.

Just my $02.

 

I notice the same with my truck at low RPMs. I think it's the crappy fuel we get down here. If I add Powerservice, Shell Rotella DFA or use Shell/Texaco premium diesel the engine will quiet down.

MikeyB

 

this almost sounds like the pilot injection cycling off and on...mine does it when its cold..but as soon as it warms up...quiet as a mouse..running on diesel that is

 

I had the same problem...put some fuel additive in and it was gone. But just make sure your not running a FRAM oil filter...it plugs up the oil jets cooling the cylinders and causes them to over heat and bang...no warrantee....good luck... :'( :'(

 

Mine use to make a knocking sound at low revs too, as mentioned like pinging in a gas engine, but some Stanadyne seems to have fixed it. With the Stanadyne it seems like it has a bit more rumble at freeway speeds. Now I hear more valve train noise than I use to, and as mentioned in another thread I still hear a ticking sound when it's warming up, and especially when engine braking downhill and just touching the accelerator.