Exhaust fumes through vent - Diesel Forum

motofan · 03-09-2005, 05:22 AM

Where do I begin, I have an '04 F250 CC, 4X4, 6.0L truck, So far the truck has been in the shop for 2 of the 11 months that I have owned it.

I keep getting a real bad diesel smell through my vents. If I run the A/C of max (the vents are closed, recycled air), I have no probs. If I run the A/C, heater/vent/defroster, I get a diesel smell. I took the truck to the dealer w/ 500 miles on it, Initially they said can't smell it, I took another one of their service writers for a ride and he said there's definately a problem. On that visit they replaced the right side exhaust manifold ( they said it was cracked). It didn't work, same problem, dealer told me to drive it and maybe it would burn off. I put on 1500 miles and still had the same problem. I returned it to the dealer, After being at the dealer for a week, they said theres nothing wrong and the factory rep told them to try a new truck and see if it had the same problem. well sure enough, bad diesel smell in it also. Truck fell apart from there, Turbo went out, air conditioning compressor stopped working, massive hesitation when cruising at 60-70 mph, No power off the line, Brakes vibrated. Several reflashes later and runs ok, but still have diesel smell. My truck did not come with hood isulation and I can see a spot on the hood (12" in diameter) mark where dirt has collected from a petroleum based liquid being on it. The spot is directly over the turbo. I have 16,000 miles on it now and I can't stand it anymore, I have ridden in my friends trucks and no smell. If anyone knows of this problem or a cure for it, please help.

I also have the shudder when accelerate from a stop, starts at 10 mph and reduces when shifts to 2nd gear and nothing when it shifts to 3rd gear. Dealer said won't do anything until I return it to stock suspension.

creeper · 03-09-2005, 01:59 PM

Did they do the Y pipes?

I had the same problem, they did the Y pipes and it stopped for awhile and now it's back. After 2 months in the shop I'd lemon law the thing.

I got mine bought back and just hope I can make it till my new one comes in. I get aweful fumes now and I lose power like crazy, I can floor it at times and the truck won't move.

Good luck.

motofan · 03-09-2005, 04:14 PM

Thanks for the suggestion,

I have read in the forum previously about the y tubes/pipe, I was hoping to get a few more responses to the problem and bring them to the dealer 1 last time before I try to lemon law it.

I absolutely love the truck, it drives awesome when it's running good, but the fumes are killing me. It gets to the point where my eyes burn and I have to open the windows to get fresh air. My kids complain then they are cold. I sure hope breathing this isn't a hazard.....

Thanks for you input,

Dieselhound · 03-09-2005, 04:21 PM

Some of the fumes that we think are exhaust actually come from the crankcase. My explanation: The Crankcase Ventilation System routes the crankcase fumes through a pipe and injects them just in front of the turbo. The turbo builds up the pressure to 25+ psi and if there is the slightest leak in the plumbing up to the intercooler and back, we get some crankcase fumes inside the engine bay. At the top of the engine bay near the base of the windshield is the air intake for the vents. When the truck is going slow or stopped, the crankcase fumes collect in the engine bay and creep up into the vent intakes, stinking up the inside of the cab.
When I smelled a petroleum odor inside my cab, I used an LEL meter, which detects trace amounts of gasses. It detected no Carbon Monoxide in my cab or engine bay, so no exhaust was present, but it did stink like petroleum, so I suspect that my post-turbo plumbing is leaking. The oil spray you are getting on your hood is evidence of a post-turbo intake plumbing leak. This leak could be causing the odor.
In summary; If the Y-pipe isn't cracked and you still have fumes in the cab, then the source of the odor in the cab is probably crankcase fumes leaking out from the intake plumbing that runs out of the turbo, through the intercooler and back to the engine.

JW350 · 03-09-2005, 05:00 PM

Has your truck been updated with the newer CAC tubes? I had the same dirty splatter under my hood. Dealer installed updated tubes and it went away. I also recall strong diesel order in the cab on occasion before the new tubes were installed. I never thought much about it because it went away. After reading the post above, I think that is what caused the fuel smell in the cab!