I have a 04 f350 dually crew cab 4x2, had gotten a recall notice early this year for a computer re-program issue, truck was running great at the time, took it to dealer, first off I had about 60k miles on truck, never pulled long distances lloads rarely over 10k only mod K&N intake. I figured I would take the truck in for the recall plus have them look at or listen to a hissing sound that started recently, can hear it outside the truck and in engine compartment when hood open. Dealer reprogramed cpu and told me the hiss was from the K&N, which I argued that with him and the mechanic, about 1 week later the truck started surging at high speeds, I would be running 65-70 and the truck would take off accelerating. Then sitting at a red light it jumped out into the intersection with my foot on the brake, thought someone rearened me, noone behind me, then in the morning atarting the truck when I wouldput it in reverse the truck would shut down when it started to roll and ideled very rough with smoke like it was missing, then check engine light came on, took truck back into dealer with K&N off and stock air cleaner on, and they said problem were not issue of their reprogram but fixed on engine warrenty, would not explain what was wrong or replaced and hissing still heard and they said they didn't hear anything, BS. Truck now runs like it has noticable power loss, turbo doesn't wine as loud as new and hissing is still there. Any ideas, comments or experience with these issues?

 

all i can figure is the deisel tech didn't follow the proper way to reflash, take it in and have them do it again.

 

Try a different dealer. It seems like the one you are going to isn't the most experienced.

 

My 03 also makes a hissing noise. Off and on at idle. It started about 2 months ago. Is yours all the time?

 

There were some wiring harness issues for that year model truck with the same symptoms (surging/lunging from stop). It's possible the hissing is an exhaust leak against the firewall from the y-pipe flex sections. It usually will leave black exhaust telltales against the firewall. It also sounds like the reprogramming wasn't performed properly if you're having performance issues. DO try a different dealer and DONT put the K&N back on--you really don't need it unless you're running some EXTREME programming of some kind (drag racing, etc.)

 

Did the service department not provide you with any documentation of the work they performed? Any time any vehicle is brought in for service, a work order must be completed. You must have a work order explaining what service they did on the truck. If they did warranty work they must have paperwork to send in to get reimbursement from FMC.


Anyway, sounds like you would be better off locating another dealer with Certified 6.0 Technicians.

 

I 2nd the Y-Pipe causing the hiss.Mine did that and it got fixed.

 

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mine sometimes does it (hiss) off and on but most of the time it is constant, sometimes louder than others.

 

Went to the dealer today talked directly to the diesel tech, new guy, he came there after I had my truck in before when I had all the issues, he said he thought the loss of power and hissing is from the y pipe also. Made an appointment to have the truck looked at and serviced. Any reason why you do not recommend the K&N, although I have not put it back on since may of this year when the truck was last at the dealer?

 

I got a copy of the service sheet but all it was was coded and the jerk at the desk could not explain it or would not explain what was done.

 

did you lose power due to the y pipe and now that it is replaced has it made a difference?

 

If I remember reading from the warranty card. If you modify the intake or exhaust of the diesel your warranty COULD be voided - also chipped. This is the primary reason why I left my 04 stock. then there are no questions. I had our 04 in for both wiring harnesses at once due to surging/lack of power. took them 3 days to replace all the wiring. Teck said it is NOT his favorite job to do. I would have hated to have paid for that bill at $90 per hr plus parts.

 

Yes that is right but K&N claims it won't void your warrenty, and I live in florida, Florida past a law that dealers/manufactures can no longer void warrenties for aftermarket parts that are "NOT" internal engine parts. When I purchased the truck new I asked the service manager and diesel tech if I put a K&N or comprable on one would it void my warrenty and I was told no. Maybe bad info on my part but I had put the K&N on for mpg not performance, which gave me only 1 mpg gain.

 

If you do a search on the K&N subject there's plenty of reading. My thing is that the performance benefit is extremely minimal at best and the protection is extremely marginal--IMHO. The stock filter provides extremely good air flow and protection and unless you're going to do some MAJOR mods you don't need it.