This is my first winter with my 6.7 and I've noticed that since the weather has been cold the motor rattles a lot more, doesn't seem to want to rev as freely and it seems like the turbo response is slower. I've noticed that my truck goes into exhaust cleaning more frequently, three times in the last week before Christmas. The transmission thumps on downshifts the colder it is. The first shift out of my driveway is between a thump and a bang. The dealer told me I'm not ready for a trans flush, it's not cold enough to need to use the engine heater and that some of the noise and lack of performance could be winter blend fuel.

Just wondering if this is a normal seasonal change.

 

I'm not sure what your definition of cold is, but yes diesel's don't run as good until they're up to normal operating temps or close to it.


Also I notice with my truck as the outside temps drop the frequency of my trucks regen drop too so something doesn't sound right about your truck. Is the engine temperature normal? Sounds like your engine may not getting up to temp and the combustion process may not be correct therefore dumping a bunch of soot into the DPF.


On the tranny topic the '11 model's had shifting issues and I believe the first order to fix it is a software upgrade.


I don't believe your issues is related to winter blend fuel, but you might trying buying diesel from another store just to rule out you may have a bad load of diesel.

 

Thanks for your reply, temps have only dropped into the single digits a few nights so far this winter. It seems like when it drops below the 30's the symptoms are more noticeable. Maybe I'll try leaving it running a bit longer before I leave in the morning, I only give it 5 minutes max to warmup at the moment. I guess I'm making something out of nothing.

The dealer did a transmission flash just after I got the truck to fix up shift issues, maybe I'll do my filter and flush early and see if that helps. I'm still 20k away yet.

 

This is my first winter in a 6.7 as well. I had a 2011 and now a 2015. In fact just coming back from the dealer myself all of my issues are normal. I can let it warm up few a few minutes or ten minutes and I don't get those transmission thumps in the 2015. Even warm out I got a lot of thumps in the 2011. It needed solenoids but since people replied that sometimes it works and sometimes it makes it worse I decided to just deal with it. I get lousy mileage in the cold, fwiw, I plug in below +20F. Do you have to, no - BUT I like heat a little quicker and it is easier on the motor.

I run PM-23A and/or Power Service. I do notice a little more knocking in the cold, but not bad. It can't hurt to try an additive and see if it helps. The station I get diesel at the fuel seems like a whole lot of #1 and not a lot of #2 fuel. No gelling, but running 100% #1 I feel more comfortable with additives. Just my .02 there.

At least you do not have a 6.0 - when those first came out they would barely move when they were cold. Later a software patch fixed that.

 

You don't say what oil your using but I'd try a 5W40 synthetic and see if that doesn't help. You also don't need to let it warm up any longer. Just drive a little easier till it's up to temp.

 

It's whatever the dealer puts in it, I don't service this truck myself. I tiptoe around in it for the first few minutes..

 

I asked my dealer about this the last time I was in and they said it was a possible solution but they wanted to do a fluid change and filter first. Going by the book I'm not due for another year by mileage. I might just have it done anyway.

 

When it gets real cold out the motor will clank and rattle a bit more till it gets warmed up.


I don't idle mine but for just a few minutes and then I drive off slowly. Driving it will help produce more heat then sitting there. Just take it slow for a couple till you see the temp guage start to move.


I don't regen much at all in the winter.


Change your fuel source.

 

Just because you don't NEED to plug in the block heater doesn't mean you can't or that it won't help. Where I live, I will NEVER need my heater, but since it came with the truck and I like warm air when I leave on a cool morning, I use it. Even at my relatively mild temps, I can tell a distinct difference between the way the engine runs and sounds after being plugged in, versus not being plugged in. Give it a try.