whistling?
 

i have an 83 300TD and i've started to get a sporadic breathy whistling sound. haven't been on the highway yet but its in the 25-40 mph range so far and seems to come and go. doest that mean my turbo is going? i was planning on taking a 1,500 mile trip with it tomorrow and it just started today. wondering if this is something vital or not? thanks

The Turbo can whistle if the turbo compressor wheel is rubbing against the compressor housing. If you remove the air inlet on the Turbo and look inside at the fins on the compressor wheel you might be able to see if it is rubbing.

The whistling can also be from an intake manifold leak or a leak where the turbo connects to the intake manifold or I guess the waste gate hose. If you make a mix of water and dawn dish soap to make a mix that produces a mix for making bubbles like kids use. Look up on the internet the proportions as I don't remember.

Spray the bubble mix over a cold engine around the areas you think might leak.

Take a short drive, just enough for the turbo boost to kick in without warming the enging up and see if there is any bubbles. If there is bubbles you have found your leak.

Check the play in your Alternator with the belts off and then tighten the belts propoperly.

I had this happen recently. Pull your air U-bracket and see if either of the rubber seals inside have collapsed. If so, you are getting unfiltered air in your intake. I fixed mine by cutting a tiny amount off the top part of the bracket.

Dkr.

What Diesel911 Said...

but for putting something to find an intake leak it is more common to use a substance which will affect the rpm's of the engine...instead of soap... soapy solution typically is for leaks sending air out of something.. for the bubble to form ..

Can't do that with a turbo...the intake is pressurized. You need to use soapy water.

You may be able to feel if there is a problem with the wheel. It should turn freely without side to side play.

It could be the seals on the U-tube leaking, OR it can be the flexible exhaust downpipe that goes down the firewall is cracked.

hmm. ok i'll look into all this tomorrow in the daylight. what/where is the air u bracket though?
i guess unfiltered air into the intake isn't good. if its one of the other options is it just going to effect my mpg and power and i could still do the drive but suffer on those two things?

(ex) wife had a 300TD turbo. The small hose to the wastegate broke off & when I drove it past a high wall, it shrieked like a banshee.

IF it is WHISTLING
it is not a pressure leak.... so I still say the soapy water is not useful .

That can also work but there has to be vacuum in the intake manifold to suck in the substance like Carburetor Cleaner into the intake. On the Diesels without pneumatic governor diesels there is supposed to be no vacuum inside of the intake manifolds.

Also such a test won't show a exhaust manifold leak.

I learned the soapy water thing from my Boss at the Diesel Fuel Injection Shop I worked at.

I have also seen him locate an exhaust leak by taking a think slip of paper (engine running) and running the paper around the exhaust. If the paper starts fluttering you have located the leak.
However it is though to do if there is not much room or the Coolant Fan is blowing strongly.