weird sound

[coondog491]

this morning it was about 34 degrees when i started my truck up to let it warm up before i took off on my 400 mile drive back home.

anyway i let it idle for about 20 min while i was in the house getting stuff together, when i went back outside i heard a incredibly strange noise coming from my truck,

it sounded like giant shop vac, it was so loud that i could not here the "clacks" from the motor. it immediately stopped once i tapped the accelerator and everything went back to normal. very strange. it ran great the whole way back

 

[sagebel]

Your Exhaust Back Pressure Valve (EBPV) was shut. There is a butterfly vavle in the turbo outlet. It is controlled by the PCM. The PCM will shut the valve when it is cold to help warm up the engine quicker. When the valve is shut don't plan on getting any power out of the truck. Some of us have "gutted" the EBPV, others use it as an exhaust brake (not recommended IMHO).

 

[coondog491]

oh ok that makes sense, this is my first diesel truck so im trying to learn as much as i can, and where i live it gets below 40 maybe 3 times a year so im not used to running trucks in cold weather

Thanks alot man