Random performance loss on 2.0 diesel.
 

V50 2.0 diesel, 2005. 231,000 miles

My car is sometimes very sluggish,other times it is OK.
I had this once before, but, it was permanently sluggish and would not rev over about 2,500rpm. Sprayed the mass air flow sensor with contact cleaner, turned out the air filter was filthy.

This time out of curiosity I removed the turbocharger inlet pipe from the front of the engine. Hope I have the right terminology here.
Looking in to what I shall refer to as the air inlet manifold, ( edit....actually it's the throttle body) is what would seem to be a a flap, it was quite oily inside this inlet assembly, no worse than when I last looked about 15,000 miles ago. EDIT... after watching some you tube videos, it seems that the air temp. sensor is here
aswell

I started the engine and sprayed carb cleaner into the manifold, aiming it at the bearing surfaces for the flap. EDIT.... probably sprayed and cleaned the air temp. sensor at the same time. Connected everything back together, went out in the car, instant turbo thrust. For all I know this was just one of those times when the car is performing correctly, and has no connection with my actions.

1) Could it be the case that this flap is jamming up, due to the crud in the general area?

2) It seems to be vacuum operated, is this correct?

The butterfly flap housing are a sticking point. Your best option is to take it off, clean it and chamfer the edges of the flap with some sandpaper or Emery cloth. I believe that is vacuum operated but they are prone to sticking. The EGR valve jams open too and requires stripping off and cleaning. Alternatively you can blank it off and unplug it, if found it made a difference in starting and economy plus reduction in smoke output under acceleration. 231k, there's hope for mine yet :)

TT

I just looked at some reviews of non removal EGR cleaning on you tube, spraying an aerosol can of EGR cleaner into the intake. One guy removed the EGR before and after the treatment, there was a visible difference.

If ..... when it happens again, I will do the chamfer suggestion, thank you.

231,000 miles, when driven gently 55mpg. I do commute in it, early morning not much traffic, 25 miles each way.

does better mpg than 2 of my bikes! BMW 1150GS, Yamaha FJ1200. Moto Guzzi California comes closer.