Possibly a couple of problems.

[KVB-R]

Hi all,

My '10, job #2, F-250 recently on a somewhat long trip started idling weird. It wasn't really a rough idle, but seemed a little cyclical or harmonious and the truck would shake in sync with the idle at stop lights. When I say shake it wasn't a vibrating but more like the someone was shoving the truck a little. Maybe sort of like someone was revving the engine ever so slightly at like 6-8 time s a second? Once I got moving all seemed fine. Like I said this was the only time in 9k miles this happened and I'm not sure if it's an issue at all...

Secondly, occasionally when I run the air conditioning I get this nasty smell which last for about 5 minutes or till I get used to it. What causes this and is there any way to prevent it? It's just a little embarrassing when you've got a good looking girl in the truck and it makes it's presence....

OK, that's all for now and thanks again to all in advance!

Kevin

[R_S_C]

mine idles pretty rough at the stop light when the DPF regen is occuring.

[KC8RXQ]

You may have mold/mildew build-up in the ductwork (if it's a sour kind of smell). If you operate in a high humidity location, and run the air conditioning all of the time, condensation in the dutcwork could be created when you shut the truck off. You may have to get a spray-can of some sort of fungicide (if that's the correct term) and spray it in the ductwork (also check the cabin air filter if one exists). Afterwards, you might try turning off the A/C and running outside air through the ductwork the last couple of miles just to bring the ductwork back to ambient temperature and minimize the condensation issue. My wife's Jeep Grand Cherokee had the same problem and that's how the dealership said to keep the problem from recurring - and it worked so long as she remembered to do it...which wasn't very often.

Regards,
Ed