I have a leak somewhere - EGR, Turbo, Exhaust Clamp or Gasket??

Something is leaking and my local dealer can't find it. At road speed I get a blowing air sound, like blowing air through your teeth. Best way I can say to describe it. The intensity is directly related to engine rpm and turbo boost. I get the normal turbo whistle but this blowing noise is in addition to that. Also I can here the turbo spool down off boost much more than normal when I lift my foot off the power. A reverse whoosh sound if you like. The dealer has looked for leaks but can't find any. Now the blowing noise and turbo noise are only there when going down the road. You don't get it when revving the engine parked, hence the dealer can't find it. So the question is what is activated at speed that is not when parked that could lead to a leak of this kind?.

is it the bloody EGR clamps / gaskets again?

 

That's something to consider. Thanks.

 

I'm taking in to TEC in Portland OR on Friday. So we'll see what they offer up. Over the phone the service advisor figured it may be air to air related as it's only apparent under boost. Bad hose or a bad clamp. Will have the CAC tested as well, good thing to do once in a while anyway.

 

Exhaust manifold gaskets on 1 and 2 cylinders were leaking. In order to fix those everything has to come off -manifold, both EGRs, turbo. I'll end up with new gaskets everywhere, so definitely 100% guaranteed no more leaks anywhere.

 

Slight soot trail around the manifold flange.

I got the dealer call late last night, apparently I have broken and some distorted fins on the cold side of my turbo impeller and the shaft has play in it. They say something must of got passed the air filter or the engine was run with the filter assembly removed. Whatever the reason, the impeller is busted up and I need a new turbo. I went down to the shop to look at it and sure enough three of the blades have pieces missing. How it happened I have no idea, but the damage is visible. So what can I do but cough up for a new turbo.

My repair costs the last few months have got stupid and it's starting to get more than a touch demoralizing. I guess at 672k things just start to wear out and fail.

 

You just have to roll with the punches sometimes and let it be. I've already authorized the turbo so no going back now. Also with the Volvo unit I do get a 1 year parts and labor nationwide warranty which is worth something I suppose. I get the truck back in about 5 hours so will report if everything has been fixed.