I have a 2006 ram 4x4 with a 5.9 cummins, 105k miles. 80% of the miles are highway miles. I ocasionally tow compact cars on a dolly (4 times a month) two hundred miles one way. No abuse what so ever but recently I notice a slight vibration when taking off slowly and when driving steady on the highway. Passing speed is not a problem if I punch it a little harder. I did noticed the vibration in park or neutral at 1000 RPM. My MPG is still 23 on the highway(according to the trip computer) at 65 MPH but the slight vibration is always there. I suspect an injector is faulty and a friend of mine alrmed me because he damaged his 2006 Dodge Cummins engine while towing a tralier and he said that there was an injector problem on the 2006 Cummins engines. Can someone elaborate on this problem? I also have a 95 Ram 3500 work horse with 325,000 miles that tows 15,000 lbs when driven and still going strong (the main reason why I bought the 2006 for my highway driving).

 

Welcome to the site. I will move this thread to the Cummins section,
FF

 

Could be an injector going, but there's a few things I'd check first as they are sort of common also.

1 - is the truck a long bed quad cab or short bed mega cab?

2 - Check the harmonic damper on the front of the engine. There is a rubber ring and 2 alignment marks. If the ring is damaged or the marks are more than 1/16" out of alignment, it needs to be replaced and will cause a vibration.

3 - Torque Converter.....could also be part of the issue.

4 - To check the injectors with this condition, the easier thing to do is bring it to the dealer. Hook it up to the DRBIII and do an injector kill test. IF you kill an injector and the idle changes, that injector is good. If you kill the injector and there is no change, that's your problem injector.

 

Thanks for the info Coal Train. I wil give your advice a shot and see what happens.

 

I took my Ram to the dealership and they told me that two injectors were partially plugged. So they charged me $ 430.00 to clean the injectors, blow out the carbon in the exhaust and perform a computer update. My Ram does not vibrate or shake at the lower rpms now but it shakes like an old maytag at 1250 rpm and up (starting at about 40 mph) until I reach higher speeds. I called the dealer and asked them to specify the two injectors and why it was still missing. The service manager told me that he would check with the technician and told me to go ahead and drive it for a couple of weeks to see if the cleaning would take effect, if not then I would have to replace the injectors. Does any of this make sense?

I would appreciate your wise opinion

Rampower1

 

My truck is a short bed quad cab

 

Is it shaking at that RPM in neutral or only when you're driving at 40 and up?

Wait a few weeks to see is the cleaning helped?.....

For the $430 they charged, my truck would be parked in front of the service bay until they got it right.

 

I do not think this Dodge Dealer knows anything about diesel engines. They informed me that injectors 2 and 5 were only running at 90%. I told them that if those two injectors were only plugged 10% than how in the hell did the $200 cleaning job not help the situation. I do not think they pinpointed the problem and I am leaning more toward the torque converter, driveline or harmonic damper. I would it figured it out myself already if it was a gas truck. It is my second diesel and I never had to play diesel mechanic as I already amounted over 325,000 on my ram 3500 dually. I went through two automatic trannys but I hear that is pretty normal and it was so easy to distinguish beacuse of the lack of towing power. Is it normal for my 06 2500 to vibrate slightly at about 850 rpm in neutral? only rpm I notice a vibration in park. When I take off it vibrates from 1300-1700 rpm, 25-50 mph , very rough at 50 mph, 65 mph seems to mellow and very rough at 70 and 75 while at 80 it vibrates a little less than 75. It has a rough time going up at 35 mph unless i punch it. That is the reason Im leaning toward the torque converter.

What do you think?

 

It sounds like you're on the right track with the TC.

When I first bought my truck, the TC was shot right off the bat and had to be replaced.

Had very much the same symptoms.

 

most dealers that charge you for "cleaning injectors" do nothing more than pour a bottle of diesel fuel conditioner in the tank, thats probably why they told you to keep driving it, you may ask them if they actually pulled the injectors out, took them apart, and cleaned them, my guess would be no...