Results from the calibration test:
1 - 71
2 - 73
3 - 69
4 - 71
5 - 67
6 - 75
7 - 04
8 - 71
9 - 27
10 - 2.0
11 - 2.4
12 - 4.1
20 - 3.2
21 - 32
22 - 00
23 - 32
24 - 11.5
40 - 164
41 - 85
42 - 104
43 - 136

Also, I took the car for a round trip 4 hour drive. During the first hour there #7 fluctuated between 07 and 16. The second hour it stayed steady at 07 and the two hours back it stayed at 07. All highway driving. The A/C stayed on and cool the whole time.

 

Your AC temp sensors are within 4 degrees spread, what is acceptable. Engine sensor shows higher, so how long it was since shut-down?
4 bars static and 16 max is low refrigerant pressure. If you really want to troubleshoot farther you should observe pressure #7 after restarting hot car, but at this point it is safe to say you need a can of r134.

 

At highway speeds you may have a lower #7 as high wind is going through the condenser effectively helping the system cool. The question is what is the ambient temp during the trip and was the beginning of the trip stop and go? Do you still have error codes?

I still say that you:

Ensure you have the proper refrigerant by weight in the system. The only way I know of is a full evac and refill. A pro machine may be able to tell you what was reclaimed by weight. Check vacuum pull for leaks see if it holds at least -27 for an hour. Add dye at that point for good measure buy a black light flashlight and monitor yourself. Its the cheapest trouble shooting to start with if you want to fix the long standing issue.

You stated that you had that the refrigerant charged several times. If you have full confidence that this was done correctly and dont want to do the above, then I will say Plutoe may be right. Your compressor. If you are going to throw that part at it, then do the drier and cabin filters for good measure.



.

 

WOW, this thread goes back 10 years, impressive. A lot of 210 A/C problems.
Folks, I see a lot of problems similar to mine, cooling on passanger side not so much on the drivers side.
In some of the earier post there is refernece to a diagnostic procedure at:
http://www.eclassbenz.com/node/27
This link does not work for me, is there a new link?
I have got the item 1 - 8 info, but would like to know that I am getting that info during the correct conditions,
.
Thanks
DougQ

 

http://www.mercedesmedic.com/ac-air-...le-codes-list/
This is the best help site IMHO.
Follow the notes to do 2 readouts.
1 in the morning for calibration test
2nd on hot afternoon to check compressor performance.

 

Thanks, kajtek1 I will do that.
Question - I have seen the chart posted by tall girafe, my car is a 210.265, which one is relevant to my car?
Thanks
DougQ

 

The posted chart is written in engineers language. Not too many actual car owners can understand it , so make your life easier and follow MercedesMedic guiding.

 

Plutoe: Following your advice I checked the stickies, and the only thread about A/C is this one.
Did I miss something?
DougQ

 

You miss the role Plutoe plays on this forum.

 

To answer your question, the difference between the .055 and your .265 is that your car is the wagon, hence the .2xx. The difference between .055 and .065 is model year, so the .055 is the 96-97 model year and the .065 is the 98-02. Being that the 210.055 is an E320, I would say that its safe to say that chart would work on your car better than it did on mine which is an AMG .074. I used it as a reference and compared my numbers to another .074 owner who replaced everything like I did so the chart was within 20% tolerance of the other member and my numbers.

 

The numbers you get 1-8 should be done before cold start and recorded after running engine temp is achieved. Also good to note what the ambient temperature is when conducting the read out. The chart should be a reference "within tolerance" so long as you follow the bulleted instructions.

 

The procedure at MercedisMedic did not work on my 1998 E320 wagon , 56,000 miles (90,000 km)..
Perhaps because it was exported to Japan initially, then to Canada by myself.
I found alternate procedures at:
http://import-era.com/threads/w210-hvac-diagnosis.1206/
http://import-era.com/threads/w210-a...tem-data.1210/

There are no error codes.
I took three readings; the first without the engine running, the second just after that with the engine running at operating temperature,
and the third at the highest ambient temperature of the day. All following the temp setting of 22C(approx 72F)
Ambient temperature almost the same as code #2. I was not sure where to set the fan speed?
These are all in Celsius.

Code #

1 21 23 28
2 20 21 29
3 20 41 30
4 20 41 28
5 18 21 31
6 20 73 91
7 04 07 09
8 19 30 40

There was no cold air with #3, but the compressor was engaged.
About a week ago I had attempted to add 134a, using a gauge set and a 12 oz can of 134a. Idle set to 2000 rpm.
I could not get the high pressure above 130 psi, and it fluctuated quite a bit.
The low side got up to 70 psi at times, and the cooling was intermittent, even though the comp did not stop.
Two days ago I was in stop and go traffic and there was no cooling, but when at highway speed I had
cooling on both sides, which was an improvement.
After the attempted recharge I was testing with temp set both to min, was alternating between EC on and off.
When EC first turned off, #7 would go up to16 then decline after 1 -2 minutes.
My limited experience is pointing to the expansion valve, but I defer to the forum wisdom.
If any other diagnostics tests are necessary, I am all ears. J

Thanks
DougQ

 

Thanks for the reply Plutoe.
With such low mileage can the compressor be rebuilt?
I have already acquired a new expansion valve and receiver/dryer.

 

Plutoe: Point taken. In looking at parts sites there is reference to also replacing the condenser on some models, does that apply in this case?

 

Plutoe: Good idea, the epc makes no reference to any requirements.

As a matter of fact I could not find the condenser on the epc, well hidden.

I will check with my local dealer tomorrow.

Thanks for tour help.

DougQ

 

I did find the condensor on a second check.
I have ordered a new comp, exp valve, gasket set and rec/dryer.
I have a vacuum pump, gauges, freon, synthetic comp oil and a special lube for the O rings.
It will be about a week before I can get to it.
A couple of questions before I start:
I have the specs for oil, and I know there are additional quantities for replaced components, do I add the total to the comp?
I had been running the engine at 2,000 rpm to add freon, but it seems that I should just be at normal idle.

Thanks for your patience.

DougQ

 

Those numbers clearly show you have no cooling as the refrigerant is low.
Might be weak compressor, but adding a can of R134 would answer the dillema.

 

Thanks for the reply kajtek1, I had unsuccessfully tried to do that.
I will be replacing comp, rec/dryer and exp valve.

One more question while doing that is if I add dye, doI subtract that volume from the freon, or disregard it?

DougQ

 

Sound like you are going for expensive parts swap without actually checking what's wrong?
You can disregard the dye.
Those systems are pretty flexible. When label says about 1000 grams of r134,they will work with 400 grams and can be overcharged as well.

 

Re: 1998 E320 Wagon
I have not yet started to replace a/c components, hopefully I will start tomorrow.
I have a question regarding the 134a fill.
On my car the sticker indicates the system requires 1.030 kg.
The cans I have are 340grams, so 3 full cans would be 10 grams short (1.020kg).
From comments it would appear that is close enough?

Thanks
DougQ

 

I had my system working even on single can. Not very efficient, but it did.

 

I need further advice on my A/C repair.
I removed the compressor, those 6mm hex bolts for the connections were a real bear.
Previous to removal the a/c had worked at highway speed and I also noticed some oil
drops on the end cap seal of the compressor.
After removal I tried to drain any oil to check for contaminants, there was no oil.
I inverted it and manually turned it, it turned freely.
I compared the turning force with the new comp and they appeared the same.
I thought there might be some oil in the rec/dryer, but it too was empty.
All connections seemed clean with the exception of 2 that had a very small amount of fine black film.
So I am wondering if I should forge ahead with replacing parts and refill or is the lack of oil an issue.
I had thought I might disassemble the old compressor to check for any damage or particles.

Thanks
DougQ

 

The compressor has only traces of oil on moving parts, when the dryer is build as oil trap and will not drain the oil from it (that's why you need to put new one with system overhaul)
When I would love to see open compressor - it might take expert to inspect the wear. Are you one?

 

kajtek1, of course I am not an expert, then I would not need any help.
If I took it apart I could see if there were any particles attached to inner surfaces, but I am not sure it is necessary.
So, my question still is do I forge ahead or need to do deal with other issues first?
Thanks
DougQ

 

If you are doing this out of curiosity to simply ascertain condition of internals, Id say no harm in opening it up to see.

In your situation, I think we are all assuming that the system has no leaks. But how do you know it isn't leaking refrigerant? What if all of this was due to a leaking hose like in the other thread?