Hi

I'm new to the list and to my 124 model with its KLIMA relay system (my other car is a 123). The AC does not cool enough during the day when temps are in the 90s to 100s.

I thought it might have something to do with the Evaparator Temperature Sensor not allowing a long enough cycle on the compressor. However, the compressor seems to be engaged most of the time. Gas looks OK. What can cause a low cooling output from the compressor? Is there such a thing as a compressor losing compression? Should I replace the Expansion valve and dryer as a routine?

Thanks All!

Oreo
91 E200 124

Do you know what kind of refrigerant is in the system? If I am not mistaken this car was designed for r12 refrigerant. I am not familiar with the rules regarding r12 in Singapore but 134 refrigerant does not do a very good job cooling these older cars once the temp gets above about 90dF - especiallly in traffic.

Is it cycling on/off fairly often? It could be low on refrigerant.

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Jim

Hi Jim

I'm pretty sure its R12. Usually I run the gas in there until I see no more bubbles in the sight glass. In the 124, the gas seems OK but I haven't hooked up pressure gauges to it yet. Might have to get the shop to do that as I'm not familiar with reading those gauges though. What should I be looking out for?

Oreo

FYI, We typically see about 42' F in the center vents on our cars. A bit higher in slow traffic.

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2012 E350
2006 Callaway SC560

BTW - has anyone here done the Evap Temp Sensor tweak with the resistors before?

Oreo

Are the fans working properly???


Beyond guessing we really need to know outside airtemperature, vent outlet temperature, high and low side pressures.

Confirm that it has not been converted to another refrigerant.

Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

Hi Michael

You are right. I need to do more testing to narrow down the problem, but I really appreciate the speedy replies from all.

Regards
Oreo

Without manifold gauges you are flying blind.

Good luck,