So it started today compleatly stock truck cept 6637 an rebuilt trans bout 5k ago it's been colder then hell here lately I always plug it in at night. But today I got a new sound outta the engine it's at low rpms like around a grand to 1500 best way I can describe it is a thumping. But if I get on it an the rpms just fly by it don't make the noise. Runs fine cept when I'm accelerating slow or holding the rpms around that range. I'm new as all get out in diesels sometimes I regret getting rid of my old 5.0 f-150. Any help is appreciated.

Thanks

 

Can you give us some more detail about this "thumping" sound? Does it go away when the engine warms up? Does it happen at idle as well? Does it change at all between neutral / park and in drive or reverse?

 

It happens in park drive 1&2 an neutral. Honestly I don't know if it does it when it warms up cause as soon as I drive it cools down alot my heat ain't even running me outta the truck anymore it's been around the low teens plus high winds. I'm actually thinking its cause the engine ain't getting warm cause it started as soon as the temp dropped this low. But then again like I said I'm new to diesels