Q: Losing power 3 litre turbo engine

I normally go for a 3 hour drive on weekends after about 2 hours doing 110 kilometres I'll lose power on the engine it drops down to about 90 kilometres and sometimes lower no matter how hard I push on the accelerator it won't budge or go any faster engine light comes on .so I'll pull over onto the side of the road . Rev It Up turn the car off for about 2 to 3 minutes start the engine engine light still on but then it picks up power I can go back to 110 kilometres but still while the light is on it's sluggish.. after about a day or two the engine light comes off on its own and I have full power as normal.. this can also happen if I go over a hard bump engine light will come on and I will lose power again again I rev hard rest for about 2 minutes start engine engine light stays on but I still have heaps of power not as good till the engine light goes off I have full power again I have done 70000 kilometres and I'm thinking it's the glow plugs. Can it possibly be the fuel filter blocked