starting and turning off the engine problem

[Erikb]

I still have problems with starting and turning off my engine. When I turn the key you can here the starter running, the engine start, but it is not the normal starting sound (really hard to explain what the problem is) sometimes you cant even here the car running, but it is on.
Also when I turn off the engine it makes a strange noise and the car shakes for second , it just sounds if it is still running on some cylinders.

Besides that it is still not running great in high revs, it makes a strange noise.

I did several boost leak test, but that isnt it. already changed a lot of stuff:

-wgfv
-dumb valve
-airfilter
-spark plugs
-fuel filter

Maybe some other injectors will solve the problem?

Or can it be that the engine is falling apart?

[Mihnea]

Erik, have you checked the compression on your engine???

[Erikb]

thanks for your reaction mihnea

Not yet, do you think this could be the problem?

What the easiest thing to check this.

[Erikb]

The engine isnt smoking, the oil pressure is at idle (when hot) 1,5 till 2 bar, when driving it is always at the end. It uses a bit oil, I refilled 1 litre after 8.000km ( i found this normall).

[S2sedan]

normal is to change oil before that ...

[Erikb]

I thought I had to change the oil after 10.000 km....