Ok Guys:

Put a 2003 engine in that was believed to have 77,000 miles.

Replaced oil cooler, egr cooler (both from Autozone), and a bunch of seals and gaskets.

I ran out of time and money to do HG's and studs.

When I did the initial startup, I noticed a thumping coming from the airbox. Not sure what this signifies?

Upon completion of project, drove from Toledo, OH to Allentown, PA in truck and it drove fine, with the exception of an 18-25 degree difference between ECT & EOT. Was there two weeks using the truck only for commuting. I did not baby the truck while I was there.

Now, for the fun part...

Driving back to Toledo engine started running poorly and codes P0281, P0284 Injector Imbalance and P2284 Injector Control Pressure showed up.

Engine started surge, and if I floored it, would seem to level off. Engine bucked a few times, idle up then back down, up then down...Then, at one point under WOT a HUGE cloud of black smoke started billowing out I let off the accelerator and the engine immediately went up to WOT on it's own. Turned the key off, truck stayed running, then finally died.

Pulled off to the side of the highway and looked for anything broken or leaking, but found nothing. Coolant reservoir was empty, so I put a gallon in. Started truck up and it idled like crap. Drove it for a mile or two and the entire time this this is putting out a steady massive cloud of what looked like white smoke...was starting to get dark out, so hard to tell.

I pulled into a gas station and started googling. I pulled out the EGR valve and it was soaked inside with what really seemed like oil, not coolant.

Anyways, a buddy drove his 1/2 ton Silverado with my 20 ton equipment hauler 300+ miles to where I was stranded. Drove the truck onto the trailer and took it home, where it's sat for the past two weeks. Pretty embarrasing for a little 1/2 ton Silverado to haul 16,000 lbs home. That was one VERY exciting drive with all that weight loaded onto that little truck's rear axle. lol

So, any ideas here as to what I'm looking at? Possible that the new Autozone EGR cooler was bad from the start? I only put 872 miles on this engine. Would bad head gaskets cause me to blow all the smoke or the EGR cooler?

Thanks for your input fellow diesel owners.

I'm sure budget and time constraints but I wouldn't buy autozone anything for my truck. I woulda rented something or ? . . Just my .02$ . . . They all thump from the air box, especially with aftermarket intake. Kudos to your friend for stressing his truck! Hope you keep posting, looking forward to the outcome!