Rough Idle

[DBoudreaux]

Ok, I have a 08 4500. Bought in Jan 09. It has always idled rough to the point where I thought it would die out at times. I had dealer check it 3-4 times over the yrs and they never find anything wrong. I have tried different fuel stops, attives, etc etc... ... ... Do the 6. 7 idle THAT rough??? Sometimes it idles fine, but the days that it does idle rough (which is atleast 4 days a week) it will do it all day long.

 

[HBarlow]

No. I only have experience with one ISB6. 7, my '08, but it has always idled smoothly.

Does your truck set codes? Is it factory original or modified?

 

[DBoudreaux]

Truck is stock. Does not show any codes.

 

[HBarlow]

I don't know the cause but that is not normal. Mine idles smoothly now at 100k miles and always has.

A dealer with a trained and skilled Cummins tech can run a cylinder performance test to measure and compare the power developed by each cylinder. This test will identify a bad injector or other problems. The test is performed in the service bay using Dodge/Cummins software and should cost you about 1 to 1 1/2 hours of labor.

Some dealers have "techs" that don't know that a Cummins diesel doesn't use spark plugs so you'll have to be careful where you take it.

I don't know where Scott, LA is but a TDR member and skilled diesel tech, Mike Mullenax, works at the Dodge dealership in Athens, TX.

 

[DBoudreaux]

I will def check into it. The dealer where I bought it is "Adren Vega Acadiana Dodge" This is my 3rd diesel from them. Always had great service, I will check into it and see what they say. Athens is about 6-7 hrs from me.

 

[HBarlow]

Sag2, who is a very knowledgeable Dodge and Cummins tech and TDR member once advised me here in the forum that the way to identify the truly trained and skilled Cummins techs is to ask about their level of training and certification. Sag2 said the best techs are Level 4 trained and certified with Cummins engines.

 

[KLauber]

Clean your MAP sensor? I just posted a new thread on that. Maybe that will improve the idle. Can't hurt.

Ken