Strange noise from engine/drivetrain

[Dany]

I am not posting very often.

I am worried about a strange noise I am hearing for a few days so far.

When the engine is working, no matter the gear it is, nothing unusual. But when I remove my foot from the gas peddle, I then hear a kind of a squealing, like if two running metal pieces, or maybe only one running, where spinning against each other. When the truck goes slower the sound is still there but the spinning of the metal parts is slower; therefore it must has something to do with the drivetrain. Further, if I put the truck on neutral or engage the cluch the sound stops immediately.

I looked under the hood, nothing unusual. I went under the truck, looked at the drivetrain, did not find anything abnormal. No oil lost anywhere.

I tought maybe the engine has moved, or is moving in some position in some occasions, causing metal pieces to touch while running. I don't really know what this is?

Anyone has any hint or idea?

Thanks

Dany

 

[SLightfoot]

Resonance

Dany, I get what I think is the same sound that you are hearing.



I get it sometimes even when I get ON the go pedal.



I usually hear it reverberate off the front of my topper, and back into the cab.



I am just about convinced that this is the turbo resonating the exhaust at just the right frequency, producing that strange metallic sound. I have definately found that the sound is turbo related.



If you hear it ONLY when you get OFF the go pedal, it could be just the turbo "barking" when the pressure differential on each side of the impellor changes dramatically, and this is normal.



My . 02



Shawn

 

[John Berger]

Me too, I think

My truck makes a droning sound--has since I bought it. The sound is similar to what a tuning fork sounds like at the low end. Does it at speeds over 45 mph and when towing. I wouldn't worry about it, but if you want to be safe, check the fluid level in the transmission and differential.

 

[Dany]

Thank you for the answer

It may originate from the turbo, but it started only a couple of days ago while the truck is 76 000 km (47k miles). That is kind of strange! Don't you think?



Dany

 

[SLightfoot]

Resonance

Well, mine only started doing it at 25,000 miles.



Shawn