Happy Thanksgiving,

I just drove from San Diego to Mammoth last night approx 400 miles. This morning I noticed dark oil spots on the driveway under the right front headlight. I got a towell and crawled under the truck and observed oil on the intercooler hose dripping down. Passenger side Duct that connects to the intercooler right behind the plastic wheel well cover "splashguard" . Not a lot but oil none the less. I checked and double checked that the oil was not coming from anywhere else. I used a whole bottle of Stanadyne when i filled up in San Diego my 62 gallon supertank. My truck has 10,000 miles it is an LLY and I'm wondering why there is oil in the duct work of the turbo intercooler. I think there is a pin hole in the duct but i'm not sure, the hose clamp is tight. Also, is it really bad to be driving it like this. Do you think it's the stanadyne? FYI I just had all injectors replaced 3 weeks ago. I wonder if my tech forgot to tighten something. shoot i hope it's not the brake line

Your help is greatly appreciated

there is a TSB for this, remove hose and clean and inspect intercooler and hose, wipe clean and install.. tighten clamp

Not uncommon

Thanks dmaxallitech,

I will look into that when i get home. Where does the oil come from? the diesel fuel or the additive?

Turbo Air Charge Cooler Hoses Oil Seepage , or Blows Off on Acceleration - kw black smoke boost noise turbocharger clamp leak oil LLY 6.6 whistle P0299 low intake surge no power #PIP3068B - (Nov 1, 2004)

Turbo Air Charge Cooler Hoses Oil Seepage, or Blows Off on Acceleration.

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The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1561746&psdid=437&evc=sm#ss1-1561746">Condition/Concern:

Oil seepage from turbo air charge cooler hoses or hose blowing off during acceleration. Possible DTC P0299.

<LI type=1>Due to the closed PCV system on the 6.6 LLY engine, it is normal to have oil residue in the air charge cooler hoses and pipes. <LI type=1>The oil will migrate to the lower areas of the air charge cooler system and may cause customer concerns of oil seepage.
This may also cause the air charge cooler hoses to blow off when turbo boost is high.
<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1561746&psdid=437&evc=sm#ss2-1561746">Recommendation/Instructions:

<LI type=1>Do a visual inspection of air charge cooler connections and hoses. <LI type=1>Replace air charge cooler hoses, pipes, or clamps if damaged. <LI type=1>Properly clean all oil from air charge cooler pipes and hoses. <LI type=1>Air charge cooler hoses and pipes are marked for proper installation. The hoses are marked with ENG, DUCT, or CAC (charge air cooler) the hoses and pipes must installed correctly. The engine side is marked ENG, the duct side (the aluminum pipe) is marked DUCT, and the charge air cooler side is marked CAC. <LI type=1>Apply a very thin coat of sealer part number 97720043 to the air charge cooler hose connections.
Install hose and properly torque air charge cooler hose clamps to 8 Nm (70 lb in).
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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1561746&psdid=437&evc=sm#ss3-1561746">Models:

(04 05 6.6 LLY C2 C3 K2 K3 Chevrolet Silverado GMC Sierra) and (04 05 6.6 LLY C4 C5 D4 D5 E4 E5 Chevrolet Kodiak GMC Topkick)

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the oil comes from the pcv valve on the 2004-5 lly's if you get into the throttle too hard ,say passing the oil will squirt out at the bottom hose . check the hose clamps both mine were lose. there will always be a little oil in the intercooler with this new engine.
this is what i found out at my dealer .

Many thanks to all and i appreciate your time

Eric