I have posted about this last year and got several replies. Truck has 46,000 miles on it we did HG, Studs, Bulletproof Oil cooler, Bulletproof EGR, pipes, plugs STC fitting etc. The drone started after all of this was completed and we cannot get it to go away.

The shop checked all of the connection on the exhaust and turbo with not much change other than the amount of drone it was making and possibly when the drone occurs.

There is also a slight vibration that seems to coincide with the drone. Even at idle there appears to be a bit of vibration, you can grab the exhaust tip and feel the vibration. From time to time you can feel the vibration in the steering wheel and accelerator pedal.

The truck runs awesome, probably better than it ever has other than this darn drone and vibration.

I plan on taking it back to the shop to see if they can find this, any input would be greatly appreciated.

 

I have something similar after having the engine torn apart and doing headgaskets. Truck runs great, but get a drone/vibration at idle and a little worse just off idle, then seems to go away at higher rpm. At first I thought it was the MBRP downpipe touching the firewall, but I verified it's not touching and even snugged the cab back on the frame mounts about 1/4" to get it further away from the back of the engine. My guess is I'm hearing drone from the new downpipe not having the stock resonator in it.

 

Interesting, it seems like once these trucks are taken down to the Head Gaskets and put back together there are little issues with the alignment of the exhaust. Good to see another Oregonian on this site.


My truck has stock exhaust so our issues may not be the same but I honestly beleive it is exhaust related since it seems to come from the back part of the engine. The shop has messed with the downpipe several times with no luck removing the noise.

 

Make sure you don't have any up-pipe leaks too. Do your boost numbers seem normal? Lock it in 3rd and do a WOT takeoff, you should see 26-28 psi when it spools up fully.

 

Yes the boost seems pretty normal. I have a scan guage and if I remember correctly it hist 26+ WOT. Its at the shop right now and they are trying to track it down.