W140 Air Condition Compressor Question

[dbmoylan]

Would anyone happen to know what can cause a "click" noise about every minute coming from the air condition compressor on a W140 chassis / M104.990 engine? Would this happen to be the air condition compressor clutch? Is this part changeable w/out having to remove the air condition compressor & discharge the refrigerant? Thanks.

 

[television]

Hello and welcome to the forum, I think that the air con system is low on gas, and the pressure is too low for the compressor to hold the clutch in.

 

[dbmoylan]

Malcolm, thanks for your reply. I've been monitoring the air temperature out of the vents and it is remaining the same temperature as normal for over a year before the recent clicking noise - 44F. I should check the pressure though I guess . . .

If it is a bad clutch, would you happen to know how to remove it? The compressor is factory supplied Japanese manufactured Nippon I believe.

I've the air condition gauges & was curious if you could go over how to check the refrigerant. Car running? Which is high & low sides? What should the pressures read approx.? Thank you.

 

[television]

There is nothing serviceable in the compressor, and I do not think there is anything qrong with it as it is working.
The cluch is controlled by sensors and user controls,if the clutch cannot stay engaged, I still think that the gas is too low, and it needs re charging, Kwik fit are the cheapest, and you must start with that

 

[dbmoylan]

Malcolm, thanks for reply. I checked the high & low sides and the readings were (evening hours w/ engine cold) just under 200psi for high side & 41 psi for low side. Vent temperature was 44F (normal).

Are these readings a bit low for a 1993 Benz 300SE / W140 / M104.990 I6 engine?

Thank you.

 

[television]

Sorry I cannot confirm what the figures should be, as air con firms have the relevant figures, and know the quantity of gas that should be in the system

 

[rapide]

low gas

As malcom says get it re-gassed, its your first port of call and cheapest option, if you look at the dryer ( should be down by the front nearside looks like long canister with glass spy hole in the top also has low gas switch on it with 2 wires coming out!) you can check the gas / fluid return with glass window, should have no bubbles in it when running correctly! if low on gas switch cuts out the clutch to stop the compressor running dry. looks like yours is borderline and they will run and work ( but not well or very cold) with hardly any gas at all! all the best Rap.

 

[dbmoylan]

Thanks guys - will check the dryer window for bubbles. I agree that recharge / check leaks may be simplest solution if indeed that is the case.