I have an 05 3500 and smell diesel fuel after I run it on the highway at 70-75 for 1.5 hour or longer. Truck is stock. I do not see any leaks anywhere. Any ideas?

Thanks

Eric

 

Check your oil level, make sure that it does not have fuel in it. Also, look at your breather tube vent, make sure you do not have excessive blow by from it. (These are signs of a leaky injector)

Next, check around the top of your tank, look in from the rear passenger side wheel well, make sure you do not have any leaks, look at the filler neck and return tube. Look at the fuel filter, make sure the lid is on tight and that the water drain is closed all the way.

Last place I would look is the CP3, make sure there are no signs of weeping from there.

If you still don't see anything, let us know.

 

My guess would be the CP3. Mine does it every winter and stops in the spring and summer.