Hi there, I have a 2010 3500HD dually 6.7TD. I bought this truck in August 2013, used, with 76K kilometers, about 49,375 miles.

At 80,000 kilometers I changed oil and filter, used 5w-40 Amsoil Synthetic. I also installed a bypass oil filter. I am in Canada, our temps are in the -20 to
-30°C. I took a sample of the oil at 89,104 kilometers, sent it for an oil analysis. I also changed the oil and oil filter.

The oil analysis came back - Fuel Dilution is marked as Critical, 7.1GC % by Volume. The recommendation was to change oil and filter (which I already did), and check for fuel leaks - injectors and lines. Oil Analysis was done by Amsoil affiliate in Edmonton Canada.

What is causing this? How do I fix it? I drive my truck almost everyday - City driving, average 75 kilometers. In the weekends, I sometimes drive 100 - 300 kilometers highway.

Thank you for any suggestions, recommendations.

 

Most likely it's going to be caused by the regen process. Do you do a lot of short trips on a daily basis?

 

Yes I do.
Also, could this also be caused(?) by the Diesel Particulate Filter?

 

Yeah that's what I'm talking about. When the DPF starts getting full, the regen process dumps a LOT of extra fuel to bring EGTs up. Some of the fuel gets into the oil pan. What I don't get is excessive fueling makes for high EGTs, but it also creates a lot of smoke. Smoke = the particles that the DPF is collecting and burning off. Seems silly.

I thought that in 2010 they had updated the software for the regen process to allow it to happen at idle. You may want to see if you've got the latest software. You may also want to change up your driving habits. These trucks with the emissions controls are NOT designed for short trips and city driving. Honestly, unless you're hauling heavy loads, most people are better off with a gas rig these days. Fuel economy is negligible between them, maintenance is a lot higher on diesels, and with that emissions crap makes for a lot shorter lifespan unless driven hard.

Make sure you use your exhaust brake all the time (except on snow/ice I guess) to keep the VGT vanes from seizing up. Give it a good hot burn on a regular basis. And I'd forget about going with stupid expensive synthetic oil and just change it more often. Amsoil won't work any better than anything else with that much fuel in it.

 

Thank you!
I am going to check on the software.

I also thought of changing oil more often, just like you said. I am also considering Valvoline Premium Blue 15w40, heavy duty diesel oil.

On the oil analysis, the recommendation was to have the fuel injectors checked for any fuel leaks.

 

Yeah leaky injectors would cause dilution, but so would the regen process. Valvoline premium blue is good oil, sometimes you can get it pretty cheap too.

I usually run Premium Blue, but I think it was Delo was on sale for $12/gal so I bought a bunch.