Tall Giraffe

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.

dougq

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

Plutoe

You have a faulty compressor and an expansion valve!

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

Nope. Did you ever rebuild a light bulb, and hope you did not go the polka ***** way and purchase used or chicom crap!

dougq

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

I do nothing on my or customer car without looking at the VIN in MB EPC to define a part(s)------did you do that to define the correct part number bla bla

dougq

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

Plutoe

Well now you are going to get PO, but you are not searching correctly or you cant read the pictures and locate the condenser as shown

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

Plutoe

The compressor oil is additive therefore add up all the spec quantities for the components that you change out.

kajtek1

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.

dougq

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

kajtek1

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.

dougq

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

kajtek1

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

dougq

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

kajtek1

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?

dougq

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

Tall Giraffe

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?

dougq

When I acquired this car (98 E320) 4 years ago it had 66,000 km, very little use and the a/c was marginal, I presume it had seldom use and the system deteriorated.
I had noticed leaks of oil from the compressor and I suspect that would also leak freon. I do not believe it had dye.
If any hoses are leaking I should be able to detect that when I vacuum the system, should I not?
It appears to me I will have to flush the system before I continue.
I have read some condensers cannot be flushed and must be replaced, is that the case here?
Thanks
DougQ

Tall Giraffe

The compressor very well may be the problem but with such extensive work to replace all the components, Id want to be sure there are no other areas of failure such as lines, valves. The vacuum will let you know if you cant achieve -27 inch or better but it will not direct you to where the leak is. Dye like shown in the link in the other thread above or possibly a sniffer will find others if any. The only items you can flush are the lines and evap. Condenser can not be flushed.

dougq

Oil A/C questions 98 E320 - almost ready to get this project finished.

I am replacing the comp (done), rec/dryer, and exp valve on this project.
I have flushed all of the system, and would like confirmation about the amount of oil and where to put it.
After I started this project I needed to drive the car before the A/C was functional, so I added oil to the new comp and installed it.
Obviously the clutch will not be energized as the sensors on the rec/dryer are disconnected and all hose connections covered.
Initially I removed the old comp, tried to drain oil (it had none), I also drained oil from new comp, which had very little.
Consulting a MB chart for the 210, I added 120 cc + 10 cc (rec/dryer) = 130 cc of pag oil to the comp plus a bit of UV dye I had on hand.
The charts are shown here:
https://imgur.com/a/1DZGy4q

So, after flushing the system I believe I have to add an amount of oil equivalent to installing new components.
By my calculations that is an additional 100 cc, if I am correct??
The second chart has an odd bottom line about the comp oil needed to be 20 cc??
When I first added the 130 cc to the comp I put it in the intake port and turned the shaft a few times.
The unit came with rubber plugs and caps which I re-installed.
So where should I add the additional 100 cc of oil?
Also in the intake port?
Or to the rec/dryer or the intake hose?
Is turning the comp by hand a few times sufficient?
I also found this gem on the net from a Denso web site:

Of course this time of year I might not need the a/c but I need to finish this project.
Thanks for any help.


DougQ

Tall Giraffe

When I replaced the compressor, I filled the 120cm- spun the shaft. Didn't add the additional.

In my case I did replace the condenser (not sure if you did) so I inserted the amount into the condenser and oil into the separate replaced components respectively-I did the dryer last after everything else was filled and closed off. Added additional for the lines into the components to compensate for lines since I flushed those. I bought a cc syringe and squirted the required amounts into the parts while they were out. It will be difficult to squirt PAG into the evaporator in place due to space. You may need to use a bendable vinyl hose from the syringe into the evaporator.

Replace and lube al O rings. Be sure you add the right amount of refrigerant by weight.

dougq

Thanks for the reply tall giraffe, I do like your idea of adding the oil to the individual components,
Did you end up with the same total that I have calculated?
That is 230 cc?
DougQ