Strange exhaust noise

[T-ROD]

Last night I was running down the road at about 1400 rpms in 4th because it was snowing and kinda slick and I noticed that when I would kept it at exactly the same rpms for a little while I got what sounded like a jake brake from a distance. Kind of like a low rythmic thump thump. I will quit as soon as I give it the least little bit of throttle and then it will stop after the rpms drop off a little as well.
Thought it was out of balance tires but just put new ones one 2 days ago and it did it with the old ones as well. What do you guys think? Should I worry or is it normal?

[Rantheman]

sorry i am not good at sound descriptions but if i was there in person I could identify it. but it sounds like your warm up valve which in the summer time you won't here unless it cold outside. but I hear mine here in oregon once in a blue moon depending on how cold it is.

[pipelayerjdh]

It's the EBPV. It is normal and aggravating in cold weather.

[CHUCK]

unplug the ebpv to be sure.

[hangnail]

does it sound like the turbo might be reliasing the extra pressure?, and you can feel the engine breaking, espeiaclly when going down a hill, mine does the same thing i find it very annoying, is there anyway around it? mine does it right at just above idle, and will do it when just driving under a light foot. under throttle though it stops.

[CHUCK]

yes, thats the ebpv working. After the engine is up to operating temp, the ebpv should stay open. if the ebpv sensor is going bad, sooted up, or the tube is full of soot, any holes in it, the ebpv will start acting up, and closing whike going down the road.