expert help needed
 

whenever i turn on the A/C, load comes into the engine and you can feel vibration on the car.

is it an engine problem? (engine cant take the A/C load) or something is wrong with the A/C ?

Could you elaborate a little more?

Do you mean that the car shakes when the AC is turned on? The AC could be going bad, which is not the entire engine.

OK the problem all started when i got the check engine light on. then whenever i used to fill my car with fuel i couldn't start up the car easily. then the problem reached to a new level. that's whenever i turned on the A/C the car used to get switch off by it self while I'm driving it. (bearing in mind that i took my car to the dealer for all the issues and they changed the air mass flow and still didn't resolve the issue nor they can find the fault).
so now after i took the car from the dealer (assuming they fixed it by changing one part) i noticed that the car vibrates while i turn on the A/C.

so the mechanic at the dealers told me that there might be something wrong with the engine that its not able to take the load of the A/C (does it makes sense?)

Sounds like your mechanics are not that skilled. To me, this much more sounds like an A/C issue, not an egnine issue. Apparently, the A/C unit (compressor) is creating a larger draw on the eingine that the system is engineered for.

Is this a Porsche dealership you are dealing with?

Donjuan143,

I see by your profile your from Bahrain, the riviera of the Persian Gulf. Obviously having the air working is a must. You said you had a CEL and the dealership could diagnose the problem? Does the service department have the right tools? They should have easily told you whats wrong with your car.

If you engine couldn't handle the load of the A/C, the mechanics should have done a compression check. With the A/C on do you get cool air? Your compressor might be on the way out. Make sure the mechanics know what their doing.