Truck is getting louder, like a vacum line disconnected. - Diesel Forum

1jeep · 01-28-2010, 07:57 AM

I am suspecting this has been going on for a short period of time, but due to the winter i drive with my windows up. Last few days were warm and i had the passenger window down slightly. When taking off i noticed once the boost got to about 20lbs i could hear an exhaust/vacum noise wooshing louder than the the actual exhaust.

I have a dpf/cat delete so my first thought was the pipe loosened, i checked it and even tried realigning it. This made no difference in the sound, it is defnietly coming from the passenger side. If i roll down just the drivers window you can only faintly hear it.

Anybody have this? what was it, the truck seems to run fine aside from this noise.

sawtooth · 02-10-2010, 05:54 PM

i had this same issue. Took it to the dealer after reinstalling the cat and dpf but nothing. Then only took off the dpf and left cat in place. Noise is definitly better but i still feel there's another issue. Just seems to be more air sound at around 20lbs. of boost. I'm going to check all my hoses and connections tomorrow.

sawtooth · 02-10-2010, 05:56 PM

One other thing. My truck seems to have just a little more power and quieter till the turbo starts to kick in. Then around 20psi or so the power seems down just a bit during light acceleration from a stop. Very strange. Its not real bad but does seem different than in the past. I'm wondering if i have a leak somewhere.

1jeep · 02-11-2010, 07:48 AM

I went by my mechanics place and had him take a ride, his conclusion was put the dpf/cat back on and that noise will go away. He checked everything and couldnt find one issue.

His point was that the dpf/cat act like a big noise damper and by removing it i now have the extra air noise. The lag time that i am seeing could be caused by the winter blend fuel, at least that is what he said. I do trust this guy 100% and will take his advice of just keep on the maintanence and drive the truck as it was intended to be driven.

With that said if you do find something let me know because i still wonder about this noise, and it sounds to be the same thing you are experiencing. My issue is i installed the dpf delete in november and never drove with the passenger window down until recently.

sawtooth · 02-11-2010, 10:56 AM

the cat/dpf delete is very loud (air noise) outside the cab on the passanger side. i've heard two different trucks now and they sound the same kinda like a jet taking off. However, if you put the CAT back in place the truck will become somewhat quieter and you will see no change in power or fuel economy as i've tested both ways. As for the sound i could even tell a slight increase in air noise inside the cab that sounded like it was coming around the rear seat passanger side with both items removed. Its wans't alot more but was noticable for me.

1jeep · 02-11-2010, 11:06 AM

well maybe my mechanic is right, its all in my head!
This is my first ford truck and 12 years since i owned a diesel of any kind so i guess after hearing all the ford horror stories i am just waiting for the big engine problem to happen.

The noise i hear is definetly coming from the front passenger side more notibly with the window down if pulling away in area with buildings or highway guard rail.

keep me posted.

compman72 · 02-11-2010, 02:34 PM

Air Flow @ RPM (compressor inlet).......744 CFM (21.1 m3/min) @ 3000 RPM
Exhaust Flow @ RPM (engine outlet)....1962 CFM (55.6 m3/min) @ 3000 RPM

With these numbers in mind there a bunch of air going through the exhaust pipes.