i had a post a few days ago http://www.dieselplace.com/forum/showthread.php?t=262875 about turbo lag wich u guys said the mouth piece was most of the proble. thanks alot im loking for one now. but as i said in the other post it seams to be damp around were the intake air tube bolts to the egr valve. it looks like carbon but damp also.i think this may b a boost leak, and my egr is blocked.?

and this i just noticed today i was driving and i got on it and let off real quick and it made a cough/sneezing sound. i dont think its turbo bark. cuz ive done it befor n it never did it the only differance is tonight it was raining. and i couldnt tell sometimes it sounds like its coming from the exhaust n sometimes it sounds like its coming from the intake.?

it looks like carbon but damp also.i think this may b a boost leak, and my egr is blocked.?


The flexible piece that connects the CAC tube to the intercooler is weeping oil from your PCV. That oil residue is meeting dust and dirt from driving and making that mess you are seeing. Personally I would pull the CAC tube from the connector & spray engine degreaser on the CAC tube... polish all the krap off with steel wool and let it dry. Put the CAC tube back on and tighten it up nice and tight.

it made a cough/sneezing sound. i dont think its turbo bark.

Your EGR blocker plate is leaking exhaust. Loosen the bolts and pull the blocker. Use some scotch brite or sand paper to take it back down to its orig shine and re-install w/ an OEM gasket. Remember when you tighten it back in... torque each side equally, moving back and forth between the bolts as you tighten them up.

Hope this helps.

its not leaking near the intercooler its on the top of the motor were the intake manifold pipe bolts to the egr. and il have to check the egr blocker thanks.

If you let off the accelerator quickly, and the truck made a "coughing" sound...I would say it was barking. You might try degreasing the EGR, and tighten op the bolts....mine did the same thing. Looks like its seeping oil. The bolts are kind of a PITA to get to, but mine were a tad loose.

well its like a coughing sound its more lika a chew..chewew...chew. almost sounds like a turbo import with a blow off valve. if u can imagine that.

sounds to me like ur wastgate is releasing the access pressure that it had built up from when you were in the throttle. correct me if i am wrong

sounds to me like ur wastgate is releasing the access pressure that it had built up from when you were in the throttle. correct me if i am wrong

LLY engine - no wastegate, its a variable vane turbo.

good call im an idiot, didn't even think bout it

i had a post a few days ago http://www.dieselplace.com/forum/showthread.php?t=262875 about turbo lag wich u guys said the mouth piece was most of the proble. thanks alot im loking for one now. but as i said in the other post it seams to be damp around were the intake air tube bolts to the egr valve. it looks like carbon but damp also.i think this may b a boost leak, and my egr is blocked.?

Sneeze480 hit the nail on the head (well.. might have missed the location but still hit the nail) the buildup you are seeing is from your PCV system. You may have a very slight leak at that gasket, but I've seen quite a few dmaxes and I've seen similar leaks. Re-route your pcv and I'll bet after you clean that off it won't return (worked on mine anyway).

well its like a coughing sound its more lika a chew..chewew...chew. almost sounds like a turbo import with a blow off valve. if u can imagine that.

I'm pretty sure that is “turbo-bark” and it's a bad thing. Predator on 85 (if I remember correctly) did it quite easily on my truck as well, 65 and 40 tunes don't do it nearly as easily. In any event it's best to avoid doing this, may sound cool but your turbo is pissed at you when it happens. Best bet is to roll into and out of the throttle in a diesel, don't “wood” it then jump off the throttle like you do in a gasser. Rolling into the throttle will also significantly reduce the turbo lag you are experiencing. It has to do with how GM tuned the truck, you stomp the throttle and the computer doesn't see enough airflow to give you the fuel you commanded so it slowly ramps up until it meets the fuel you're demanding.