Loss of turbo / major power loss on C250 TD

chizzel89

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Feb 27, 2011
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Pembrokeshire
Your Mercedes
Mercedes-Benz C250 Turbodiesel Sport Auto. Estate. 1998. 180,000 mls
This has happened once or twice before on my car, but it seems to be happening all the time now particularly after long trips.
One minute the car will be pulling fine, then I will come to put my foot down to overtake something and there will be nothing there- no power increase. However it will still cruise at high speeds without problem. It's as if the first inch or so of throttle works as normal. The fuel filter is definitely not blocked. These cars are a bit sedate until you really floor them, and then there is a fair lag where the turbo spools up and the box changes down but then they go like the clappers. The speed will only gradually climb with my foot pressed on the floor. If I go to kickdown, the box will change down twice as it should but the engine will still not produce any power and struggle to meet the required RPM for it to shift to the next gear (about 4800 rpm).
I did once forget to reconnect the boost compensator gubbins when Id had the inlet manifold off once- felt exactly the same as this but this time it is definitely connected.
How can I diagnose this? On STAR?
As far as I can see it can either be a problem with the intelligent turbo wastegate or the boost compensating side of the fuel system?

As I said, the car has done this before but only very briefly. I remember when I was driving up a steep hill about 2 years ago, went to put my foot down and nothing happened. This happened more than once but in general it has been fine until now.

No warning lights on the dash at all.

Any tips much appreciated. It isn't any fun having "Turbodiesel" on the back of the car, and plodding up hills at 40mph with your foot to the metal!
 
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yorkshire1

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Apr 10, 2012
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East Yorks
Your Mercedes
"98 S202 C250TD Manual hybrid
vac

as Steve suggests if vac problem T vac guage into relevant line/s and fasten to wiper and watch as you drive not sure what max vac readings should be though
 

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