Are the electric fans blowing air into the rad or out the front? ( Use paper to check )

I don't know if yours are 1 or two speed.

Thanks 97 SL320

Yes they are pulling air towards the engine compartment. is the second speed on those auxiliary fans suppose to come in at any time in this model?

If one pulls the sensor by the top radiator hose, they kick on to second speed, but do they ever do it on their own?

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CM

The high speed function of the fan is engine tempreature based, they will kick on when the cylinder head temperature gets close to 105C. (you tested that by removing the plug on it and they worked) - the relay is controlled by the pushbutton HVAC unit in the dashboard.

In original form the front condenser fans push air into the condenser and the engine fan should start to heat up and start working. But as the fan is rpm dependant you may lose some performance at idle.

Can you check that the resistor for the slow speed function is not charred/burnt - a charred resistor does slow them down further and eventually cuts the circuit open. In simple words you should not be able to slow down the fans with your hands, they should be having considerable torque even at lower speed (be careful with this test)

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Ok Friends,

Yesterday afternoon I got a chance to check on those fans, they seem to be running nice and strong. Found it a bit hard to make them stop actually.

I am under the impression that the system has air, or it was charged incorrectly.

After the new compressor, new expansion valve and a new dryer - the vent temperature goes down to 52 only and on the highway and up to about 68 at idle if left long enough; Before while on the move it would dip down to 38 on the vents while on the highway and climb to 70 on a stop I left long enough.

I did noticed that the water temperature on the car seems to run a tad closer to the 100's and that the fan clutch is engaged. Perhaps because that high pressure is a bit too high?

Thanks again folks in advance for your guidance.


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CM

I have a 95 E300 as well and recently recharged the AC due to loss of charge from ruptured pressure switch, it actually blew freon through the electrical pin connections. Anyway I pulled a deep vaccume on it for about 6 hours, kept gauges locked down over night to verify no leaks. Next morning it still had 29 in of vac so I let vac pump run for another 15 min and proceeded to charge. I pre weighed the freon cans also weighing an old empty and got the charge perfect per label, charging only vapor with can in a bowl of warm water to assist in charging.

That has been 4 months now and it's so cold here in Houston tx even you gotta turn it down. It's equal or better than my 2011 gl350.

I would say you have some air or over charged? Does yours have the sight glass? Mine is on top of accumulator and the bubbles cleared up right when the exact amount of freon was finished.

Mine has since it was new a condenser, evaporator, expansion valve, and pressure switches.

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1995 E300 (W124)
1999 ML430 (w163)
2011 GL350 (x164)
2016 Sprinter 144" 4X4 lowtop (906)
2004 E500 (W211) 4matic Wagon (Gold)
2004 E500 (W211) 4matic Wagon Avantgarde (silver)

Since you charged by WEIGHT you are in good shape...

HOWEVER,

the use of the site glass is prohibited according to the MB FSM AC manual because there are circumstances where even with the correct amount of refrigerant THERE CAN STILL BE BUBBLES in the site glass..

It can be used for other diagnostic purposes... but most cars do not even have a site glass now due to so many people using it to determine the refrigerant charge when they have just had a leak and were not totally starting from Empty.

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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

Sorry to hear that AC performance is worse after all the new parts. Do you know what kind of equipment was used for the recover/recharge? Did they recover and charge from the same tank? Or did they use a virgin tank of R134a? If from the same tank, it is possible it is contaminated with "whatever"- air? other refrigerant?. Or it could be incorrect amount of r134a.

Does your fan look like this one? To properly clean the entire condenser, the fan assembly has to come off. You will likely find the area on the condenser hidden by the fan motors filled with leaves.

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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

X 10 .
and bugs...

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

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 wanted to give a quick update on the issue.

I took the car to an old Merc. specialist here in Miami, he went through all of the issues that usually cause this problem; It turned out that the system had way too much oil in the system, he also noted while flushing out the condenser that there was too much dye in it.

So after three flushes the high pressure is down to 250 in 95 96 degree weather. They are still having a look at it since they are still noticing that the car takes a bit too long to cool down when sitting on the sun for too long; They are focusing on the duo valve (I believe that this car has a single valve) They had clamped down the heater hoses to see if there was an improvement on it.

My brother and my dad took the valve down as they tend to leak and dis-assembled it last year; Put in some new o-rings (radiator grade ones) on it and some good old fashion strong glue, since the new ones also tend to leak rather soon.

I wanted to gather thoughts and opinions from our friendly community on that 250 PSI in 95 96 degree weather; Perhaps is still a bit too high?

As always your kind advise is greatly appreciated.

Many thanks

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CM

Yup, Funola those radiator fans look just like in the one in your picture - they are both spinning nice and strong.

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CM

Well guys I wanted to give another update, I got the car back and it is cooling incredibly well.

With an IR thermometer I can see about 16 degrees out the vents when driving and about 36 out the center vent while in traffic for a long time. The car is black on black, and for it being about 92 to 95 degrees lately here in Miami, on top of that very humid and that it does not seem bad at all.

The car now cools while standing in traffic. Which is great.

They suspect that the duo valve may not be closing completely.

Which leads me to the my next question. What hoses on the 95 E300 would be the ones to check and see if they are "too warm" for one to suspect that the valve is slightly open?

I would like to take the opportunity and monitor them a bit closer to determine if it requires replacing further down the line.

As always your advise is greatly appreciated.


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CM