Hissing Sound From Manual Transmission

[diesel4camping]

Recently, I have started to notice a hissing sound, similar to the sound you hear when metal rubs metal such as the rotors when pads are wearing out.

The only time you can hear this is during cruising speeds of about 55 mph or less and only in 3rd, 4th, and 5th gears. The sound goes away when under acceleration. The sound can be heard through the shift boot.


Any thoughts appreciated.

Thanks and Merry Christmas.

 

[BIG JOE]

Throw-out Bearing ?

 

[jestersv]

how long have you owned the truck (new to you?) and has it just started since it turned cold? i'd suspect maybe just normal waste gate noise.

 

[iracemine]

X2 on ebpv. mine will come back on when cruising and idling, but go away when accelerating.

 

[diesel4camping]

I have noticed it since it has gotten cold. I have only owned it since late April this year. So the only time I have really driven it has been during the warmer months.

I appreciate the help.

 

[JLDickmon]

throwout bearing or MAYBE input shaft bearing..

 

[bbressler]

I'm gonna say it's the EBPV...

It's normal, the PCM closes the EBPV (Exhaust BackPressure Valve) to aid in warming the truck up. The EBPV is located just after the turbo, it's what the downpipe is connected to. Some folks remove the butterfly valve to prevent this behavior (and gain more airflow out the exhaust). Others make it into a exhaust brake. If you want to disable it, there is an electrical connection on the drivers side of the turbo that has two wires running to it. You can unplug that, it shouldn't set any codes or anything.

 

[jestersv]

if it goes away with light throttle its just ebpv completly normal almost sounds like its coming through the pass side floor right?

 

[diesel4camping]

Yes. Sounds like its coming from the passenger floor area and/or shift boot.

Thanks for the help.

 

[JLDickmon]

Yes. Sounds like its coming from the passenger floor area and/or shift boot.

Thanks for the help.

is it steady? or is it a few seconds on, a few seconds off?