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  #1  
Old 04-19-2014, 01:28 PM
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Determine is it intake or exhaust leak sound?

1982 300d turbo NA. I hear a whiseling sound when I accellerate with my foot nearly at the floor. How do I determine if it is an exhaust leak, or the intake manifold, or the turbo compression of gasses without shooting in the dark with hit or miss repairs of the aforementioned three possibilities. I did one repair replacing the downpipe, still hear sound.

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Old 04-19-2014, 04:47 PM
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Originally Posted by Mesalm View Post
1982 300d turbo NA. I hear a whiseling sound when I accellerate with my foot nearly at the floor. How do I determine if it is an exhaust leak, or the intake manifold, or the turbo compression of gasses without shooting in the dark with hit or miss repairs of the aforementioned three possibilities. I did one repair replacing the downpipe, still hear sound.
You need one of those generic pump spray Bottles that People pour Liquid Houshold Cleaner into.

You mix 1/4 cup of Dawn Dish Soap in 1 quart of water but don't shake it hard. This makes a mix that they use at the Preschool where My Wife Workd that kids use to blow Bubbles.

Your Engine needs to be cold. Spray the Bubble Mix on the areas you believe a leak can come from and start the Engine and rev it before it gets too hot.

If you have an exhaust of intake Manifold leak it should bubble.

You can use that Bubble Mix to detect most types of gas leaks where the items are not hot enough to burst the Bubbles and there is enough internal pressurecoming out to create a Bubble. Besides Engines I have seen it used on Tires and House Hold Natural Gas Connections.
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Old 04-20-2014, 04:37 PM
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It seems that the radiator fan blowing will affect the bubbles. I use a flame to find household gas leaks.
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Old 04-21-2014, 01:12 AM
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It seems that the radiator fan blowing will affect the bubbles. I use a flame to find household gas leaks.
In order to effect Bubbles there has to be Bubbles. Also I think the Fan Clutch is not going to have the Fan moving as much if the Engine is cold when you start off; if there is a Fan Clutch.

It used to work for Me and others when I was a Diesel Mechanic. On a 617 it would not be hard to turn the idle speed down if someone thought the Fan was going to be a problem.

The other way I have seen can also be effected by the Fan. You take a about 1/4 inch wide lenght/strip of Paper and move that around the areas where you think there might be a pressure leak. The Paper will flutter if there is a good leak.

Works best on an Exhaust leak espcially between the Head and Exhaust Manifolds. I have seen My past Boss do that.

Also better to start off with the Engine Cold.
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Old 04-21-2014, 10:03 AM
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Originally Posted by Mesalm View Post
1982 300d turbo NA. I hear a whiseling sound when I accellerate with my foot nearly at the floor. How do I determine if it is an exhaust leak, or the intake manifold, or the turbo compression of gasses without shooting in the dark with hit or miss repairs of the aforementioned three possibilities. I did one repair replacing the downpipe, still hear sound.
A thing that can cause the Turbo to whistle is that as the Thrust Bearing in the Turbo wears the Compressor Wheel gets closer and closer to the Compressor Housing. If that goes on long enough the Compressor Wheel will rub on the Compressore Housing.

The meatal to meatal contact makes noise.

This happens mainly because the exhaust pressure on the Exhaust side of the Turbo pushes the Exhaust Turbine the towards the Compressor end of the Turbo.
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Old 04-21-2014, 10:49 AM
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For exhaust leak checking only ,
Get the hood up and ensure engine is stone cold,get someone to turn the key and attempt to start the engine without waiting for it to have any glowplug heat.
This will ensure that it cannot fire up properly and will fill your yard with grey smoke,it will also billow out of any exhaust system or manifold leak.
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Old 04-21-2014, 11:04 AM
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An exhaust leak is easy to find- just look for soot where it shouldn't be.
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Old 04-21-2014, 04:25 PM
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Thanks, those are all good ideas. I will try to find the problem.
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Old 04-21-2014, 10:57 PM
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In the old days People used to spray Carburator Cleaner with the Snorkel Tube attached around intake Manifold joints while the Engine was running. If the Engine Speed picks it is an indication the Fluid is being sucked into the Manifold through a leak.

I have never tried that on a Diesel so I suppose instead of the rpms increasing it is possible you woul hear some nailing.

Also I have in the past come acrossed some Carurator Cleaner that is not very volitile and I don't think it would have burned.

Obviously you cannot be too close to the normal Air Intake while you spray the Carburator Cleaner.

Somepeople also claim they hear the sound of the Turbo "Spooling". Not sure what that is supposed to sound like but on a 617.952 the the Turbo boost pressure effect seems to be around 2000 rpms.
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  #10  
Old 04-22-2014, 02:42 PM
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Excellent idea! I was thinking of trying a propane torch not lit-up.
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  #11  
Old 04-23-2014, 11:28 AM
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Keep in mind that even at idle, a turbocharged engine may have a slight positive manifold pressure, so a leaky intake won't aspirate any gas or liquid.
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Old 04-23-2014, 05:14 PM
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Quote:
Originally Posted by Mesalm View Post
1982 300d turbo NA. I hear a whiseling sound when I accellerate with my foot nearly at the floor. How do I determine if it is an exhaust leak, or the intake manifold, or the turbo compression of gasses without shooting in the dark with hit or miss repairs of the aforementioned three possibilities. I did one repair replacing the downpipe, still hear sound.
Two questions:

1) You do realize that "NA" = naturally aspirated (i.e., non-turbo), right ?
2) What color is your car? I'm always trying to place local W123 & W126 diesels.
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1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

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Old 04-23-2014, 05:51 PM
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I took NA in this instance to mean North America, since he said turbo right before that, and the North American ones were the ones that got the turbo for the most part.
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Old 04-23-2014, 06:15 PM
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Originally Posted by Skippy View Post
I took NA in this instance to mean North America, since he said turbo right before that, and the North American ones were the ones that got the turbo for the most part.
Ooooooooooooohh... du'oh!
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1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."
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  #15  
Old 05-03-2014, 01:38 PM
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Sorry about the confusion. Yes it was NA, North America. Jooseppi, Die farbe ist Dunkelblau.


Last edited by Mesalm; 05-03-2014 at 01:59 PM.
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