Black smoke

[grancito]

My turn to have a 6.5 failure, better get the old truck back on the road. Black smoking low power and SES flashing. Will pull the code tomorrow.

[Chevylover]

Black smoke, low power and flashing SES ? Sounds like Wastegate solenoid or something that has to do with like cracked hose.

Cu,
Sven

[grancito]

Thanks Chevylover I'll look for those mañana.

[firetruck]

I seem to be having a similar problem with my 96 k3500. Only my problem is intermittent and I am not throwing any codes. I blow tons of black smoke going up even the smallest hill, I stop check the vacuum to the waste gate and find none, but I do have vacuum from the pump. I decide to limp it home and on the way the smoke clears up and I get my power back, once I'm home I check the vacuum and sure enough I have full vacuum again. I'm a little stumped. Is it the vacuum controller module that needs to be replaced, or is the ecm fouled up, or what? As I said before I get no check engine light at all. My vacuum pump was also recently replaced so I don't think it's that. Any help would be appreciated!!!

[grancito]

Now mine is OK again but it had a 78 code, "waist gate solenoid failure" that has not appeared again. It would come on when the speed was increased, and I expect it has something to do with the intake air temperature, or sensor, as I was towing an 8 ft wide box trailer at 75 mph in 106 degree air temperature, with engine temp 195. Air conditioning running and one nearly flat trailer tire.Someone may be able to tell us if the air temp sensor stops the turbo at high intake temp.

[toddg58]

I had the same issue... I replaced the waste gate soleniod.... what a difference it made....

[grancito]

Solenoids, coils etc suffer from heat when they are sick, I´ll see what is around to replace it, but will try to get it hot again and see if unplugging the intake heat sensor has an effect.

[grancito]

I tried to reproduce the problem today but without the trailer, so put the air on, and outside temp 105 , speed 85 mph engine temp at 195, normal is under 190 then booted it, but no smoke. Problem gone or hiding.

[ercaduceus]

I had the same problem it turned out to be the intake pressure sensor. Evidently it fails on the safe side and tells the computer to kill the boost. No boost = black smoke and decreased power. Problem was intermittent for me as well.

Good luck,