I spent the day trying to figure out my lack of the throttle response, and came across something unusual. Every time I shut the engine off I could hear air being sucked through the air filter. Lasts about 5 seconds. I tried listening with the engine running as well, but couldn't hear anything unusual there. It even did it when I reprogrammed the truck to stock. I cannot recall ever hearing it before, so I don't know if it is normal. It is an 01 F350 Power Stroke, with a K&N air intake. Any ideas?
Thanks,
Ron W.

 

The turbo will continue to spin for 30-45 seconds after shutting the engine off. Without the engine running, there is no where for the air that the turbo is trying to pull to go. If you are truely hearing air movement through the intake, rather that the turbo spinning, I would suggest checking your boots for leaks as that is about the only place it could get out. A blown or seriously leaking boot would make your PSD run like a dog.

 

It is definately getting sucked through the air filter. What is the best way to check the boots? Thanks.
Ron W.

 

To begin with, visually. You should be able to grab them and pull with no movement of the mating surfaces.
If they are oily, pull all of them, wash is soap and water until they are squeeky clean. Clean the metal mating surfaces with acetone, laquer thinner or other solvent that does not leave a residue. Clean the clamps and reinstall making sure the clamps are straight and square to the boots.
Test drive and see if you problem is gone.
Many of us have done the CCV mod to eliminate the oil in the CCV gasses from being dumped into the intake and making this mess in the first place.

 

my guess would be what you are actually hearing is the turbo winding down, it sounds like air bieng sucked in but I would be it's not actually any air movement.

 

I agree with monsterbaby... While my AIS system cuts the noise from under the hood, with th 5" cannon out the back the turbo spinning down echoes between my house and the neighbors for about 20 seconds. How do you know there is air being pulled in?

 

Thanks guys,
Last night I checked the tightness of the clamps I could get to on the air intake and the intercooler. They were all tight. The boots going from the underside of the turbo to the engine are dirty, not really sure if I would want to tackle that. I'll mess something up there for sure. :-)
It might just be the turbo winding down. It only lasts for about 5 or 6 seconds. With the hood open, I shut the engine off and run to the air filter and hear, what sounds to me to be air, at the air filter. Like I said, by the time I get to the air filter I have about 5 seconds to figure out what is going on. Never noticed this before until yesterday.
While I am on the subject, when I am coming uo to highway speeds, under moderate throttle pressure, when the truck shifts into OD at about 45 mph I hear a fairly load whoosh sound for about a minute or so. At least until the truck gets up to about 60 mph or so. I have always attributed this to the K&N air charger, as this started when I replaced the stock system.
Ron W.