Shane1979

Hi there, just joined this group today and hoping someone might be able to help me. I have an 08 6.7 cummins and have a HS Mini Maxx, EGR/DPF delete and 4' turbo back 4" exhaust with a small muffler. The problem is that right after the deletes were done there is a metallic noise coming from right behind the centre of the dash we I come of the accelerator ... its doesn't do it (or I can't hear it when accelerating) but as soon as come of the peddle its there ... I have tried it on different settings on the HS and with the jake brake on an off .... I have also taken the dash apart and eliminated any possibility the something being loose behind there. Someone mentioned that it could be a waste gate flap but i Have no idea where that is or even what it is ... any help at all would be much appreciated !!!!

Busboy

If you deleted the EGR cooler then take off the rear nut closest to the engine and install another washer under it then reinstall it. The threads on that stud are either not long enough or the stud is not inserted into the head far enough so while the nut is tight it's not holding anything down.

Shane1979

Hey thanks for the reply .. It sounds like that might be the solution .. The cooler was removed and the only part that's left is the bracket .. Is that the part that you mean .. Sorry I'm not that mechanically inclined so not to sure what part your referring to .. The sound actually does sound like possibly a loose bolt .. Can you describe the bolt you mean ?? Many thanks for your help

Busboy

Merry Christmas... The 2 thick steel blanking plates that cover the 2 holes where the EGR cooler was removed from.. the rear plate, inboard stud and nut (closest to the engine.) That plate may have come pre-drilled for an EGT probe, anyway add the extra washer under that nut. If that doesn't fix it then perhaps your exhaust pipe is the problem, either at the turbo or perhaps the down pipe rubbing. Just deleted my sons 2013 on Tuesday and after we test drove it the exhaust rattled on engine shutdown we had to take it apart again to add a muffler to quieten it down and made sure we had more clearance the second time around.

Shane1979

Hey it worked !!!! Many thanks !! I actually tighten the bolt accidentally while trying to get it off and it took care of the noise right away .. I guess it just needed a tightening ... Thanks again you were a huge help .... The next issue I'm trying to sort out is that we I accelerate hard between 80-100 km the truck vibrates ... Only under heavy acceleration normal driving won't cause it ... Feels almost like a small airplane taking off when it starts ... I had the U joints checked and they were fine ??? Any ideas

Busboy

Thanks for the feed back, glad it fixed it. You should fill in some details about your truck so people know what truck we are talking about. If you have a two piece rear drive shaft have a look at the hangar bearing, the one mid way along the drive shaft, if there is ANY indication of rust around the bearing it needs replacing, also look at the rubber mounting for the bearing. Make sure the rear transmission mount is tight. If all this is ok the drive shaft could be out of phase, meaning the yolks are out of alignment. A twisted drive shaft or the drive shaft not assembled correctly.