Recently the a/c condenser on my '95 E300D sprung a leak and I was faced with installing a replacement. To save a few bucks I decided to take a chance on one from the local Pick-n-Pull DIY auto scrapyard. I got lucky and found an apparently good one from a 1993 300E (6-cylinder, twin-fan cars all got the same condenser). A clue that the condenser was good was the hissing I heard as I disconnected the refrigerant lines. Apparently the yard guys didn't completely empty the system before putting the car out in the yard.



The surprise came when I removed the old condenser—I thought I had been keeping it so clean! With the aid of a pressure washer I cleaned the fins of both the radiator and the new condenser before re-installation. The second surprise came when I discovered the a/c worked better. This I could see, not in the temperatures achieved, which didn't change, but in the actions of the compressor and the aux fans. With clean fins the condenser worked for efficiently: the compressor now doesn't run as much to keep the interior cool and the aux fans don't run as often to keep the refrigerant pressure down. (Both of these I monitor in the cabin with a couple of LEDs.) The green LED illuminates whenever the a/c compressor's clutch is engaged by the Klima relay and the yellow LED whenever the pressure switch in the refrigerant line turns on the aux fans in low speed.



Without some other reason (like my leak) I can't recommend people disconnect their a/c plumbing—refrigerant is expensive. However, it should be possible to remove the cooling system's radiator, allowing it to be cleaned outside of the car and the condenser to be cleaned in-place. I recommend anyone whose car hasn't been touched in this area for many years to at least take a look, see how much is stuck in the fins.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I noted a small hiss when I cut an AC hose to remove a compressor at PickNPull recently. I attributed it to being in the sun on a 100 F day. They probably recovered the refrigerant on a much cooler day. It is a good sign, especially in R-134A systems where the oil can absorb moisture to form corrosive acids.

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I just did the condensor on my 300te and it was just as nasty as yours.

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Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

Anything sitting directly in front of a condenser will reduce the AC performance including shrouds and aux fans. If you look at any of the late 90s and up MBs all the cooling aparatus was moved behind the radiator. I would at least ditch the shroud in front of the condenser.

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CENSORED due to not family friendly words

That's a good suggestion. The lower few inches of the shroud (where all of the dirt/leaves are in my picture) is actually behind the bumper and doesn't get much direct air flow. The worst part is that the shroud is closed at the bottom so that anything falling into the little gap between the shroud and the condenser stays there and is almost impossible to remove.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Disagree about the shroud in theory and in practice, in pusher or puller configuration. The shroud increases cooling by directing the air so it goes through more surface area of the condenser/radiator, instead of just the area in front/ behind the fan blades. This is true only if the fan is not in contact with the condenser/radiator, e.g. mounted on it with Nylon straps (which is not a good way of installing a fan). With a good fitting shroud, there must be an air gap between the fan and radiator/ condenser.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Somewhat similar principle here - the shroud works somewhat similar to the old F1 ground effects cars. You need to keep air from escaping at the tips of the fan blades, letting them produce more pressure.

https://en.m.wikipedia.org/wiki/Ground_effect_(cars)

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'85 300D - federal spec, built in late 84. 85 300D Complete AC System Rebuild

Except there is no such thing as a good fitting shroud, certainly not the stock shroud sitting in front of the condenser. If you look carefully around the perimeter of the shroud there are always leaks. Put your hand behind the radiator with the aux fans running and theres barely any airflow getting through. And when the aux fans are not running the shroud is simply blocking airflow. There is really no way to make that plastic thing air tight around the condenser. This is not F1 technology. Its ill conceived and MB got rid of it around 2000. Cooling fans are only effective behind the radiator.

My 190e went from this.


To this. Pic was taken before reinstalling the radiator.


Guess which setup has the colder AC? Not only that but the engine stays cooler because there more air getting through to the radiator even when the electric puller fan is not running.

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CENSORED due to not family friendly words