Problem Turbo whistle?
 

uh ohhhhhhh... My turbo is running at 0.5 Bar... well thats where it sits... (about 7psi) I didnt set it there.... and I have the whistle of all whistles. I mean like it turns heads..... course the whole rig turns heads. I thought the whistle it was cool and normal. It does continue at all times once it starts and only stops once I decelerate and reach below a certain point in the RPM. This is the only MB I've ever driven or heard though. At what RPM it starts I have no clue since I dont have a Tach.

Sooo anywhoseee... I have a stack exhaust like a big rig and no muffler. Just a small silencer. This thing certainly sounds to whistle from the exhaust stack and not inside the engine housing if that's what ya mean by intake whistle. Might I have an intake air leak?

83-84?? 5cy Turbo D

2D^
 

2D^ (To the top)

for the morning tech heads

Wow. Looks like I started a hot topic here.... whopeeee :D

Anyway..... if anyone has a clue on my question here is some more info.

I can here the turbo windup.... and wind down.... as in the whistle increases and decreases accordingly..... but it does whistle a high pitch tune on down the highway when the RPM's are high enough.

Depends on the turbo -- my Volvo has people looking around for the police car -- in variable traffic it sounds just like a cop car about a block back. Annoying. Better, though, than the quiet turbo on it when I bought it -- no power!

I would guess an air leak. MB usually has pretty quiet turbos, but that stack with a vortex type air cleaner may let a lot of noise out. Check the high pressure parts for split pipes, leaking seals, etc. If the boost is venting off, it will whine a lot. Boost will be low as a result of the leak, although 9 psi may be about right, depending on the engine series (617s were 9-11 from the factgory, 13 psi max).

Could also be something loose in the front of the turbo, too, but that won't restrict boost.

Also, check for an exhaust restriction! My brother's 300SDL started whistling when the trap oxidizer plugged up. The seal for the exhaust line to the trap blew out, the rest of the system was plugged. No boost, no power, but great milage.....

Peter

Well, I dont have to worry about it being exhaust restrictions issue cause when I bought this thing and had it shipped; they cut off the exhaust to help it fit into the shipping container. Sooo when I got it it had no exhaust.... It sounded just the same but a tiny bit louder. :D

Boost Facts
 

If whine is an indication of a mortally wounded turbo, then there must be thousands and thousands of turbochargers that only are moments away from destruction. Frankly, I'd be surprised not to hear a lot of turbo whine with the un-muffled and relatively straight exhaust tract that's on your Mog.

And, is your post of .05 Bar correct or is that a typo that should read .5 Bar? .05 Bar is only .72 psi. and is not a whole lot of manifold pressure.

I'm assuming that you really meant to type .5 Bar (7.2 psi). And, that the whistle you are hearing is similar to what you'd hear on an turbocharged over-the-road 18-wheeler and not a metal-on-metal squeal.

Before doinking with anything on the turbo, or assuming that the whistle means that something terrible is going to happen, you should find out the following:

1) Boost specs for that particular engine (an OM617, right?)
2) Verify accuracy of your boost gauge

Later,
R

Yes 0.5 bar (about 7.psi as I stated) thanks for catching the error Ill correct it.

You are correct in that their is no metal to metal squeal.

Ill have the easy things cheaked at least.

any other comments?

Run it!
 

More thoughts...

.5 Bar sounds a tad on the light side since 617s are supposed to run something like .8 Bar. But, that difference could simply be your gauge calibration. Try to find another air pressure gauge and plumb it in temporarily to compare the readings.

It's possible that, given the genesis of your engine (a stationary engine in a tech school?) the wastegate has been monkeyed with at some point. Or, it may have been 'detuned' for enhanced reliability but that doesn't really make much sense because the MB is so darned reliable anyway.

If the whine is objectionably loud, maybe you could add a tractor muffler to the stack? I know also that sometimes the stacks on marine engines wind up being lenghened or shortened to eliminate objectionable harmonics...you may be experiencing the same sort of thing with that long, straight stack.

I do think if that Mog was mine I'd just run it...if there was anything wrong with that turbo or the oil supply, it would have died long ago. If the turbo ist kaput, go get another off of a junker.

Just my .02
R Leo

I dont object to the noise. My reasoning behind this post was simply to understand my engine better and to help catch poetential problems as soon as possible.

This thing will be making a long Journy in Late Aug, Early Sept. so I want to get this thing in tip top shape prior till that.

I just won an EBay auction for a 617 perfermance book of sorts so this will help me better understand things too.