Some days, my truck runs perfectly with no smoke, though there’s a bit of white smoke on cold startup.
Other days, I get black smoke on every take-off with low power until the turbo kicks in, then it clears up, only to bog down at the next stop/start.
Sometimes, it starts fine, but on the highway, I lose power until the turbo boosts again, then it’s fine for the rest of the day.
The white smoke on startup is always there. Could this be a bad oil cooler, injector, or something else?
These are the codes I’m getting:
EGR (P0404 - P0405)
Low boost (P0299)
Glow plug #7 (P0677)
Gale said:
These are the codes I’m getting:
EGR (P0404 - P0405)
Low boost (P0299)
Glow plug #7 (P0677)
The EGR valve is likely causing these symptoms. Try removing it and see if it’s able to fully close. You can also leave it unplugged to see if that resolves the issue. If it does, replace the valve or leave it unplugged. I’ve had mine unplugged for over a year now with no check engine light.
@Bailey
The EGR valve looks pretty new compared to the rest of the engine. I’ll pull it out and check it. What does leaving it unplugged do? Does that keep it fully closed?
Gale said:
@Bailey
The EGR valve looks pretty new compared to the rest of the engine. I’ll pull it out and check it. What does leaving it unplugged do? Does that keep it fully closed?
Yes, leaving it unplugged keeps it closed. Sometimes, a newer-looking valve means someone already tried to fix the issue. If that’s the case, it might be a wiring issue instead.
White smoke on startup is usually due to glow plugs or stiction in the injectors. Low boost and black smoke could mean sticking vanes in the turbo, and you might need to clean or replace the EGR.
Neo said:
White smoke on startup is usually due to glow plugs or stiction in the injectors. Low boost and black smoke could mean sticking vanes in the turbo, and you might need to clean or replace the EGR.
Stiction won’t cause white smoke at startup – glow plugs would be the culprit here.
Ford diesel generations:
Heavy duty → super duty → pooper duty → sleeper duty → trooper duty.
Reese said:
Ford diesel generations:
Heavy duty → super duty → pooper duty → sleeper duty → trooper duty.
For reference, it’s a 2006 F350 with the 6.0.
White smoke at startup usually means raw fuel, likely due to a glow plug or GPCM issue. The P0405 code points to the EGR valve; pull it out and check if it’s partially open. If it is, that’s likely causing the issue. If not, try driving with it unplugged – if that solves it, it’s the valve. Just note that some trucks will throw a check engine light, depending on the year.
@Briar
Also, if you pull the EGR valve and it’s wet or has large carbon buildup, that could mean an early-stage cracked EGR cooler. A cracked cooler can also cause white smoke on cold starts.
@Briar
Is it okay to drive with the EGR unplugged for a while?
Gale said:
@Briar
Is it okay to drive with the EGR unplugged for a while?
Yes, you can. You may get a check engine light, but it’s okay as long as the EGR cooler is fine. Some trucks run the fan clutch through the EGR valve, so tuning is sometimes recommended.
Update:
Air temps are cooling down here, and I noticed that on startup, it blows mostly white smoke for 10-15 mins, then I get a few mins of black smoke with low power until the turbo kicks in. After 20 mins of driving, everything clears up and runs fine. EGR inspection planned for tomorrow.
Unplugged the EGR valve – no smoke at all, and it’s running great. Can it really be this simple?
Gale said:
Unplugged the EGR valve – no smoke at all, and it’s running great. Can it really be this simple?
If the P0404 and P0405 codes point to the valve, it’s likely faulty. If the valve is wet, the EGR cooler might also be cracked. Sometimes, the fix really is as straightforward as it seems.