I have a 54 plate sharan, i have just ad it serviced and since then when driving it when i put my foot down or am climbing a hill it starts to judder and loses power, i don't think its the air mass metre as i never had this problem before it being serviced! my mechanic has put it on a machine and nothing is coming up wrong? the only thing he said was that maybe it's too clean and need to clog up slightly! please help.

You did not post the year make and model BUT you should not drive the vehicle because when the check engine light flashes, you can cause damage to your engine. You need to get an OBD reader from a chain autoparts store and see what codes are present.

contaminated fuel, fuel filter clogged, injector ports caked.

If the car heats up trying to generate revs , then it Seems like the clutch plate is slipped.

is it auto matic or shift . if shift its clutch judder oil on clutch plate

There is no problem with the revs going to 3 or 6. The revs need to climb so you have enough power to climb the hill (if the car upshifts under heavy load it may stall). But are you saying that the only way you can get it to shift out of first is to turn off the car? if so, then that is obviously not supposed to happen. It should shift shortly after you start driving down hill.

diesel engines have loads of pulling power(towing/loaded)but you need to use the gears to keep the revs at peak torque.1st is a crawler gear(very low ratio).put car in 3rd going down steep hills saves the gearbox overheating.....

100% sure it shows one of your cylinder compression is weak, please do a compression test to isolate the problem and get the head/pistons checked . This is a known problem with VW/Skoda 1.2 3 cylinder mills..

Simple answer, no, it will not most likely cause any increased wear to your engine or transmission. Yes, it is normal for the engine to rev while climbing a hill while in cruise control.

The cruise is designed to be used on flat (or semi-flat) stretches of highway at 55mph or higher so you don't have to hold the fuel pedal the whole time and your foot doesn't get tired. The cruise control system will try it's best to keep your vehicle rolling at the set speed, increasing/decreasing the throttle to compensate for changes in engine load.

If you are driving with cruise on, try lightly putting your foot on the pedal and you might notice that the system will actually move the pedal itself. If you are in cruise, and you come up to a large hill, try putting your foot on the pedal and getting it up the hill on your own w/o cruise then resetting cruise once you are off the hill.

Also, cruise is not supposed to be used in moderate/ thick traffic or on country roads with a lot of rolling hills. The cruise control system is a "dumb" system meaning (not that it's pointless) but it will only change the pedal as the speed changes and it has no idea what's coming up next, even while you are already on the hill.

So, it is normal operation of the cruise control to try to compensate for a hill by constantly revving up the engine and letting it fall back down to try to keep moving at the exact same speed you set it for. If this is a bother, you can always use your foot to hold the pedal while climbing the hill normally.

Don't worry, it won't cause any increased wear and tear on your vehicle. I hope this helps. Good luck and don't forget to rate! Thank you!

1.6 zetec surely ,for this year