Black smoke deceleration.

obs'r · Jul 31, 2011

Hi, my dad bought a super duty 7.3 this past fall. To my knowledge the truck is stock. While looking under the hood the other day I noticed two bolts on the exhaust housing on the turbo had completely walked out. Luckily they never left the top of the turbo and I was able to put loc tite on them and put them back in. I pulled the intake hose off and inspected to make sure it spun well and there was no play while I was there. Everything seemed fine. We hauled a load of tractors to a show today and the truck ran great! There was tons of boost compared to what we had. When we got home I dropped trailed and took it for a Drive around the block. Was in od and floored it to see what it would do. When I let off there was a cloud of smoke that poorer out of the exhaust. It was almost like a turned up p pumped cummins but it happened when I let off the pedal. This greatly concerned me and I could not get it to happen again. This truck is bone stock accept exhaust which is just straight piped. I have no idea what is wrong and dont have any idea where to start.

Cody · Jul 31, 2011

my truck pre modded would do this only on rare rare occasion i never really dug into it and modded it shortly after

obs'r · Jul 31, 2011

So you don't think it's a big deal then?

Cody · Jul 31, 2011

i can only recall it happening one time vividly and after i shut the truck off it didnt do it again to be honest i totally forgot about it untill i read this thread, that was almost 30k miles ago on my truck

obs'r · Jul 31, 2011

Ok well I wont worry about it too much then. Thanks for your help!

dmd · Jul 31, 2011

It is a 2000? Those bolts that fell out were common then if they are the four that
hold the housing to the center. They made some new bolts that wont come loose. No
matter what you try they will come out again, some even tried ceramic hold tight
and they came loose...

obs'r · Jul 31, 2011

Yeah it's a 2000. Wonder why they come out?

Arisley · Aug 1, 2011

Safety wire. That will stop the bolts from ever backing out.

http://www.customclassictrucks.com/techarticles/1003cct_how_to_safety_wire/photo_01.html

tbolt · Aug 2, 2011

Maybe just a pipe full of smoke that had to clear after lifting.

SkySki Jason · Aug 4, 2011

Ya mean like this? :cursing:

The other (2) bolts that hold the housing on are down here - the turbo hold-down bolts are 'in the way' of replacing them...

This didn't cause any problems, I just noticed it on a pre-trip inspection. AFAIK, other than losing drive pressure, the only damage from this would be if housing moved enough to contact exhaust wheel. The oil seals, journal bearings, etc are in the center section.