Air Con putting too much load on motor

[nath 134]

Hi guys

I have a reasonably powerful car which runs really well and is well maintained. However when you turn the air conditioning on (which blows nice and cold) it puts a very noticable amount of load on the engine. Enough load to make it shudder and sort of vibrate at idle which is definitely not normal.

Does anyone know much about air con systems to suggest what may be the prob? Crapped out pump shaft bearing maybe?

Seriously hard to actually get to the pulleys etc without taking front of car off as the motor is right smack up against the front of the car.

[jeffbebe 1559]

Hi guys

I have a reasonably powerful car which runs really well and is well maintained. However when you turn the air conditioning on (which blows nice and cold) it puts a very noticable amount of load on the engine. Enough load to make it shudder and sort of vibrate at idle which is definitely not normal.

Does anyone know much about air con systems to suggest what may be the prob? Crapped out pump shaft bearing maybe?

Seriously hard to actually get to the pulleys etc without taking front of car off as the motor is right smack up against the front of the car.

Same thing happened on my 528i when the compressor was on the way out. Had to replace in the end but whilst investigating the problem I did find out that you can get a fair bit of vibration if it's not got enough gas - this can unbalance the compressor and make it shake and overload the engine as it's working over time to keep cool.

Get it checked and if the gas level is low try a re-gas first. If that fails, replace.

[nath 134]

Excellent thanks, I'll take it into a shop this week.

Bit of a bugger if it needs replacing!

[nath 134]

An update here too, turns out a switch in the radiator/cooling system musn't be working as it is turning the aux elec fan to 'full load' as soon as air con is turned on. Air con is just meant to put the fan at speed 1, not full current draw! Hence loading the alternator right up and thus loading engine.