Potential Air Con issue????

[swirl80]

to follow on from a recent thread i started regarding an engine whine (dealer declared it was nothing but couldn't explain what it was or why it wasn't there the previous week.....), i've recently been getting another noise a more of a vibration/labouring/revs too high for the speed i'm travelling at which didn't happen consistently but more often than not it was when coasting to a junction, or pulling away slowly. Now, i have noticed that the noise becomes apparent when i switch the air con on or have it running. If i don't have the air con on i dont get the noise at all.

Has anyone had this before? Is it the fact the air con unit is putting extra strain on the engine and its not revving enough to cope therefore giving a kind-of-a labouring noise

As soon as i switch the air con off it doesn't happen.....

[Handyandy-UK]

Might well be the compressor on the way out. You switch the aircon on - the clutch engages and if say the compressor bearings have gone, then you get the strain on the engine as the compressor isn't spinning freely. You switch aircon off, the clutch disengages and the strain is taken off the engine. Sadly, the compressor is the expensive bit
You might want to get it checked by an aircon specialist, or get under there and see how the compressor bearings feel to you - should be a nice, smoothly spinning pulley when engaged - no rattling.