wondering if anyone can shed some light on my problem, i have a disco 300. is very short of power, makes all the right noises but seems really gutless. loses power on the hills too. i have changed the manifold gasket as it was leaking, took out the air filter, not put in a new one yet. changed the fuel filter. cleaned the intercooler out, wasnt bad. need some help, still has all the egr rubbish on but dont think that will cause this. head gasket looks good. does have a whine fron a tensioner bearing though. help. its emmbarassing.