o my AC system is showing about a 35 on the gauge when I hook it up, psi I am guessing (no I am not an a/c guru as you can see). It blows hot air on the drivers side, and used to blow cold on the right side, now it is only room temp though. The compressor is kicking on, the aux fans are going. I know I have seen on here that the r-134 systems are filled by weight, but other than a low charge, what would make it blow warm air? Especially on just 1 side?

Talking about the 96 by the way.

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1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

Duo Valve ? (Heater Control Valve,regulates the HOT coolant that Warms P.C)

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'84 300SD sold
124.128

It's probably low on refrigerant. The pressure when not running means nothing. The pressure when it is running means a bit more, but not without knowing a bunch of other things, one of which is the high-side pressure.

Throw away that cheap recharge hose and get some real equipment. Including a thermometer.

Got exactly the same results that you mention, along with a hissing sound coming from the center vent with the ac on. AC unit needed a little recharge, and all is well. Hopefully that is the same cure for your issue. Good luck!

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96 E300d

" Hissing sound from the center vent...."
I am not sure we can categorically call that a good sign... until we know what is causing it...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

I tested it with good equipment, with the system running, on the low side. Don't need a thermometer to tell me the ac isnt cold.

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1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

I have that same hissing sound. I will take it to the a/c shop and get a recharge.

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1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

Were you working on the system or just checking?

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination

The hissing from center vents on a W210 usually means it is low on refridgerant.

Why not get the AC actual values from the CCU and also pull error codes?

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I assume that it's a W210. They do that when low on refrigerant. It is quite noticeable.

The high-side pressure is very important. The thermometer is for measuring the air entering the condenser, as well as the actual vent temperature. The relative humidity in the cabin is a good idea too, but you can usually get away with guessing at that one (it doesn't change the pressure that much).

It is the 210. How can I get the actual values from the CCU?

I have not checked the high side, just the low. I will get on that as soon as I can.

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1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"

Just checking. I can't do much with these cars. Almost always have to take it to the shop.

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1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"