I have a 2001 F250 7.3L PSD. I have added a Western Diesel Chip (60HP/100 Ft-lb torque), a Banks exhaust system and an AFE air intake system, which I have been running for about two years now. Over the last couple of months, I have noticed a high-pitched whining/buzzing sound whenever the boost gets over 20PSI. It doesn't sound like normal turbo whine or turbo "barking." I haven't seemed to lose any boost pressure. EGT's are OK. Seems to get slightly worse with colder weather. Any thoughts?

 

Could be the exhaust is touching something .

 

I thought about that as a possibility, but I've had the Banks system in place for about two years and the noise just started. Anything specifically I should look for with the exhaust? It sounds almost like air is escaping from somewhere in the turbo or intercooler system, although I haven't seemed to loose boost pressure.

 

I know this doesn't sound near of what you are saying but the power steering pumps are known for making weird noises on fords. It could be a pump going bad and making noise at high rpm. Also check the silicone hoses that connect the y-pipe to the intake plenums, I have heard of loose clamps before?

 

Well, I did lose some power steering fluid about a month ago. I refilled the reservoir and haven't had a problem since. Haven't seen a leak and haven't had to replace any fluid. Also, I haven't had any problems with the steering and haven't noticed any strange noises that might be associated with the pump going bad. I will check that out, though. Incidentally, I did tighten all of the hose clamps -- didn't seem to make a difference.

 

Usaully if a hose come off / loose from the intercooler it makes a wheezing sound and you will lose power ( depending on how big the leak ) ......Start with the turbo and work down the downpipe to the exhaust pipe , some times they move just enough to touch when you accelerate , then again it could be the alternator ? But if it only makes the noise at a certain boost it may be in the induction system , look the hoses over for cracks.....But then again !!

 

I had the same whine on my 2002 psd with chip,exhaust and afe intake.mine started whining when towing 11,000 lbs fifth wheewhile passing a semi up hill on freeway.I have a friend that works at ford and he replaced the turbo and the noise was gone.He said he could not find an thing wrong with the turbo.

 

I second wheelieman's comment. I think your turbo bearings or something have gone belly up. Only cure is a new turbo. With all that neat stuff already installed how about a nice big ball bearing turbo?

 

Couldn't this also have something to do with the exhaust valve thingy? Mine makes some noises similiar to air rushing out of a small tube and I don't think it is my turbo because I only have about 12k on this turbo (long story but suffice it to say that screwdrivers and turbine blades don't mix well). The sound goods away with slightly higher RPMs and is completely gone when at operating temp. Of course after re-reading your post...it seems that the whining/buzzing doesn't go away so maybe a different problem. Thoughts anyone?