soo i noticed my dads 99.5 whistles louder than my 2000 at an idle..we got the same exhaust the only thing we have different if i have the age stage 2 and he has a stock set up, soo why does his whistle louder?? i think i might have a boost leak somewhere due to smelling diesel fumes in the cab every once in a while..any idea's? why his would bw louder whistle?? maybe i do have a boost leak??

 

Look at your up-pipes for black soot at the connections. If you are smelling fumes in the cab, that is a likely place for an exhaust leak.

 

ok ok, if its a bad leak would it make the turbo not spool up as fast maybe?? therefore not makin it as loud???

 

Yes, you will not get the wheel turning as fast and will be loosing boost. My turbo whistles pretty loud when I start making boost. Also, every truck with the same mods will not sound the same. Have you looked to see if he has a WW installed?

 

I can't tell you whether or not it is something wrong, but my father-in-law's 2002 seemed to have a louder whistle than my 2003 and his also has the stock air box whereas mine as the 6637. I was kind of surprised when I drove his a couple of months ago, and wondered if the open-air filter had something to do with it.

 

Sorry if this is hijacking, but can someone explain exactly which pipes are the "up-pipes?" Forgive my dumb question.

 

The up-pipes are the pipes coming off the back of the turbo and go down to both exhaust manifolds. Stand on the drivers side of the engine bay and look behind the turbo and engine. One going down each side.

 

This is a shot of my bellowed up-pipes before they were installed on my truck.

 

And here is a shot of the old style donut pipes on an E450 that were leaking so bad that the turbo barely spooled up.
See all the black streaks all over the pipe and the bell housing?
That is loss of exhaust drive pressure, a very bad thing on turbocharged engines.
After I changed them out and the owner drove away, he called me within two minutes and asked me what all that whistling was.
It was his turbo finally doing some work!

 

The other thing that may be going on here, is the older truck may have an old style "wicked wheel" and the 2000 model doesn't. My fathers 99 really whistled a lot louder than mine until I put the WW on my truck.