bad cutt

iTrader: (5)

Hi, I have a 2003 gmc sierra k 1500. I have a t4 76 trim turbo on it. in spring i broke the pump on the trans so i replaced it test drove and it was ok. After the test drive i parked the truck and it was idling in the shop, i walked away for a couple minutes and came back to a shop full of smoke. as i was running to the truck to shut it off, I heard it knocking. I towed it home, pulled the engine and found some worn bearings, so I started a rebuild. I came across a aluminum 5.7 block so i used that along with my rotating assy,( stock 5.3 crank, eagle h beam rods, diamond pistons, new wiseco rings and clevite bearings). So I got it running wednesday and it was idling for about40 minutes and just started smoking. Badly!. So, I was checking things out and noticed, a black, oily fluid dripping from the right exhaust manifold. So I pulled the plugs and checked compression, all 8 cylinders betwen 175 and 180 psi. So I performed a leak down test, all less than 10% leakage. So I was thinking maybe valve seals, as it was smoking just like before the rebuild. I replaced the valve seals last night and started it this morning with the same results. The truck is not overheating, but I am thinking poss. a head gasket didnt seal up right. the smoke is whitish but i am running water. so it shouldnt smell sweet and doesnt. I have no milky oil or sign of compression, in the coolant tank. I am thinking of draining the water, putting coolant in and see if the smoke has a smell. Any ideas or suggestions? i work on cars for a living I am an ASE master tech, and have been working on cars professionally for about ten years now and i am completely stumped. Am I overlookig something simple? also i pulled the intake tube off the engine to see if it was possibly turbo seals. the throttle body has no residue on it. and with the engine running no smoke is coming through the intake tube. again any ideas would be great.

Seth.

Coban

iTrader: (14)

Have you checked he exhaust side of the turbo to see if oil is leaking there? I don't know if the seal can only go bad on one side.

bad cutt

iTrader: (5)

I dont think i would see something dripping from the exhaust manifold at the engine if it were the turbo.?

thunder550

iTrader: (70)

Are you running a restrictor in your oil feed to the turbo? I bet it's just getting too much oil pressure and seeping past the seals. I had to run a restrictor in mine to get it to stop smoking at idle.

bad cutt

iTrader: (5)

i'm not running a restrictor, but it never smoked with the old motor. also i dont have oil going in through the throttle body( no residue) and i can see oil dripping from the right exhaust manifold. could it still be a restrictor issue? that would be awesome if it was? how bad did yours smoke? and what did you use to restict the line with?

charcold-bowtie

iTrader: (10)

stock heads?

bad cutt

iTrader: (5)

yes, stock heads, wondering if one cracked?

SincalT/A

iTrader: (16)

Are you running double valve springs.

bad cutt

iTrader: (5)

no double springs

thunder550

iTrader: (70)

If it's leaking from the turbine side of the turbo you won't see any oil in the intake manifold. I ran a nitrous jet as a restrictor, I think I was running a .04 or .05 jet. I've heard not to go below .035. All I did was cut the flare off the male fitting on the turbo and drop the nitrous jet in there, which acts as the flare and restricts the oil flow into the turbo.