Hello everyone! I'm a new member here but I've been reading the forums for a while. I've got a strange situation with my truck - its a 2003 F250 6.0L with about 86000 miles. The truck has a bunch of work done, and used to smoke like a fiend with a reasonable tune. However, a few weeks ago, the black smoke more or less went away. It'll still blow smoke at full throttle, but nowhere near as much as before. And, under normal acceleration there's now a small amount of greyish smoke. I don't think its oil or coolant, and the amount of grey smoke will be almost nothing if I detune the truck back to stock settings or into a tow tune. Needless to say, theres no black smoke at that time as well. At start, there's a small poof of grey smoke and then it idles clean.

There doesn't seem to be any decrease in performance or fuel economy. In fact the truck starts and runs completely fine. I don't notice anything different about oil/coolant temp, EGTs, fuel pressure, boost or anything else. I'm just at a loss as to why the black smoke has gone away, and want to make sure there isn't something wrong that I'm missing. My mods are:

-ARP studs
-18mm Victor Reinz head gasket
-MDM EGR Bypass
-190/100 injectors
-FASS Titanium fuel/air separation system
-FASS 125GPH @55psi fuel pump
-Strictly Diesel regulated fuel return
-Powermax Turbo
-New oil cooler
-Custom intake
-Sinister coolant filter kit
-4" downpipe
-5" exhaust, no cat, no muffler

The heads were recently removed from the block, the engine block surface was cleaned, and new machined and o-ringed heads were installed with the new headgasket and ARP studs. I run Mobil 1 synthetic 15w-40 and 45 cetane diesel.

I'd appreciate any ideas or advice - I can't believe that the truck would just stop blowing smoke for no reason at all. I have a CTS Edge so I can datalog or pull info as necessary.

Thanks!

 

It's not getting as much fuel as it was before or it's getting more air. With the turbo the air part would need to be a boost leak that healed up or maybe the VGT solenoid sticking before and now it's not. Sounds unlikely. I'd try fresh fuel filters and check fuel psi and if possible, fuel flow. It would seem with those mods fuel shouldn't be an issue. Can you monitor MAP/BARO/EBP? Is it possible the tune has changed somehow?

I'm curious about the VR gaskets. Are they black Onyx (full rubberized coating) or the Black Diamond gaskets? How are they holding up?

 

To be honest, I'm not sure about the headgasket. I know there have been some issues with VH head gaskets, but if there was really a problem wouldn't I be burning coolant and be blowing white smoke? I haven't changed the fuel filter in about 10k miles so I know its about due, but would it cause this type of problem? Wouldn't performance be affected with a clogged fuel filter? I'm going to order a new one just to be safe.

My main question is whether the appearance of the greyish smoke is bad? I'm not sure if it was hidden in the black smoke that was present before, or if its something that just developed. Could it just be cause by a lack of a catalytic converter?

I'm going to datalog MAP/BARO/EBP my next drive.. I'll post it up ASAP.