AC Problems
Junior Member
Joined: Feb 2016
Posts: 25
Likes: 0
98 E320 Wagon, 74 280C
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
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
MBWorld Fanatic!
Joined: Jun 2004
Posts: 3,589
Likes: 32
From: Austin Texas!!!
2001 E55 OMG
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.
Junior Member
Joined: Feb 2016
Posts: 25
Likes: 0
98 E320 Wagon, 74 280C
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:
Thanks for any help.
DougQ
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:
Never add oil directly into the compressor, always add it to the condenser, receiver dryer or second evaporator cycle.
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
MBWorld Fanatic!
Joined: Jun 2004
Posts: 3,589
Likes: 32
From: Austin Texas!!!
2001 E55 OMG
Oil A/C questions 98 E320 - almost ready to get this project finished.
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?
DougQ
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?
DougQ
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.
Junior Member
Joined: Jan 2007
Posts: 41
Likes: 0
2014 GL350, 2000 E320, 1989 328GTB
AC Problems
Has anybody run into an issue on when the heater is turned on, there is a major leak of r134a? The ac runs fine during the hot summer months, but as soon as that one day when it gets cooler, the heater turns on, all the r134a leaks out? Do you know what to look for to repair? I refilled with r134a and it’s fine but when heater is on, low in r134a again.
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Junior Member
Joined: Feb 2016
Posts: 25
Likes: 0
98 E320 Wagon, 74 280C
Finally got my A/C back up and running.
I wish to thank Plutoe, Tall Giraffe and kajtek1 for their input.
As mentioned I have replaced the comp, rec/dryer and exp valve.
That exp valve was a lot of fun, totally buried.
I managed to get the water collector out without taking out any circuit boards.
I flushed all the system and learned not to use rubber hose for that.
I flushed a lot of solvent through the evaporator before realizing I was flushing the rubber hose on the output as it disolved.
I had a little dribble of oil as I was starting to add it to the evaporator input.
So I had to guess the ammount of dribble and put it in the output, where it stayed.
The system held 30 in of HG, over night, so I was confident it would not leak.
Of course the weather is not conducive to testing A/C, but we had a very sunny day that heated up the car and cold air was experienced at all vents.
Hopefully it will be the same next summer, and of course the dehumidifying effect will help during the wet months.
DougQ
I wish to thank Plutoe, Tall Giraffe and kajtek1 for their input.
As mentioned I have replaced the comp, rec/dryer and exp valve.
That exp valve was a lot of fun, totally buried.
I managed to get the water collector out without taking out any circuit boards.
I flushed all the system and learned not to use rubber hose for that.
I flushed a lot of solvent through the evaporator before realizing I was flushing the rubber hose on the output as it disolved.
I had a little dribble of oil as I was starting to add it to the evaporator input.
So I had to guess the ammount of dribble and put it in the output, where it stayed.
The system held 30 in of HG, over night, so I was confident it would not leak.
Of course the weather is not conducive to testing A/C, but we had a very sunny day that heated up the car and cold air was experienced at all vents.
Hopefully it will be the same next summer, and of course the dehumidifying effect will help during the wet months.
DougQ
MBWorld Fanatic!
Joined: Jun 2004
Posts: 3,589
Likes: 32
From: Austin Texas!!!
2001 E55 OMG
Congrats! Im sure its a great feeling to get it working. In my case I stripped one of the allen bolts in the exp. which made the journey leading to it all that more fun at the end 
Also I had to go there twice since I had to replace the evaporator after a failed hope my evaporator was ok.
Im still surprised you actually flushed the condenser.
If you took your time and were thorough, you should have a long lasting system.
Also I had to go there twice since I had to replace the evaporator after a failed hope my evaporator was ok. Im still surprised you actually flushed the condenser.
If you took your time and were thorough, you should have a long lasting system.
Newbie
Joined: Apr 2026
Posts: 2
Likes: 0
2002 Mercedes E320, 1999 Mercedes ML320, 2017 Mercedes E300.
Good morning everyone, I was hoping to jump in and see if anyone can assist. I have a 2002 Mercedes E320 (W210). I have an issues with my AC system. It has puzzeled everyone that has looked at it. So I am hoping for some help. When you first start the car, the AC will not kick on. But anywhere from 20-30 minutes after running. The compressor and electric fan will cycle on and off. We have pulled the ACC codes and they are intermittent for the coolant circulation pump, smog sensor, and light sensor. I had the circulation pump replaced. I resent the codes and there is currently no codes. I had the refrigerant levels checked and they are normal. So far, if we apply power to the compressor and the fan, it will run just fine. We also attempted replacing the controller, but that did not rectify the problem either. I did an actuator flap test and everything worked fine, I also went through the P1 and P2 settings and they we changed to a P1 and 40 and a P2 of 152. Any and all help would be greatly appreciated. Thank you!
MBWorld Fanatic!
Joined: Jan 2004
Posts: 5,939
Likes: 178
From: Seattle WA
99 E320
(responding to post 387)
What were the actual codes displayed? Also, did you specifically test and use the climate control diagnostic....not the standard ODB trouble codes?
example
What were the actual codes displayed? Also, did you specifically test and use the climate control diagnostic....not the standard ODB trouble codes?
example
Newbie
Joined: Apr 2026
Posts: 2
Likes: 0
2002 Mercedes E320, 1999 Mercedes ML320, 2017 Mercedes E300.
Good afternoon,
This is a copy/paste of a prior comment I posted, which should encompass everything. Let me know what you think-
"The E320 is currently sitting at a shop, so I don't have access to the most recent numbers, but here is what I had prior as I was trying to diagnose-
1. 73
2. 82
3. 60
4. 60
5. 60
6. 195
7. 12
8 127
9 29
10 1.4
11 2.7
12 4.3
20 6.7
21 32
22 0
23 32
24 11.6
40 164
41 91
42 104
43 152
Please note that these were before the secondary coolant pump was replaced.
At that point, I was getting a Eb1416 and a Eb1234 fault code.
I have since had the secondary coolant pump replaced and to date,do not have any error messages.
The shop that current has my car has tested the refrigerant system and found no leaks, they said the pressures were almost perfect. They said when they send power to the compressor itself, it will engage. So, they through the issue was the climate control unit, we ordered a replacement unit, but after putting it in, had the same issue. Therefore, they put the original head unit back in.
Also, the VIN for my car is WDBJF65J42B489614 if that helps with anything. I am waiting to hear back from the shop as to what the original P1/P2 values were at, but currently, they are at P1- 40 and P2- 152. The original P1 and P2 codes on the head unit were 104/152 prior to changing anything.
I will say, when I went to the shop a few days ago with the information I found from your prior help, I started the car and the engine RPM went up at idle and the fan was running, after changing the P1 and P2 codes, all was working well, but at that point, the car had already been running for a while. We also swapped one of the relays from the battery area ( I think it was for the fuel pump) with one ( I think controlling the fan) in the fuse box to the left of the engine bay (if you are looking at the car). And there was no change there.
I purchased the car from a "reputable" mom and pop dealer in town about 6 months ago, during which time it was cold outside, so I thought the AC system was not allowing the compressor to come on because of the low ambient temperatures.
I don't know if this helps at all, but when we purchased the car, there was an aftermarket radio in it that had not been installed correctly. I removed it and replaced it with the correct radio, and everything seems to be working well on that front. Also, the climate control system seems to be working well. I have no interior blower issues; the temp splits on the passenger and driver side seem to be fine, all of the flaps seem to work well, etc. The only issue is getting the compressor and fan to come on normally. I have had quite a few of these W210s and have never had this issue, so any and all help would be greatly appreciated.
Here is the issue in a nutshell-
Say the car has been sitting overnight or during the day, I would say it needs enough time to cool down, but I don't have a specific time length. Then, you get into the car and start it, and the AC does not work. It is not intermittent; it never does. And it is not temperature dependent. But sometimes you can let the car warm up for 15-20 minutes, and it will work; sometimes it won't. But if it does work, it works every time after that. You can stop the car and turn it off and back on and it will work, you can let it sit for a little while and restart it and it will work. It is very weird.
If you are in the fault codes section on the climate control head unit, it will kick the compressor on every time.
Sorry for the long message, but I wanted to give you as much context as possible. Thank you again for all of the help!"
This is a copy/paste of a prior comment I posted, which should encompass everything. Let me know what you think-
"The E320 is currently sitting at a shop, so I don't have access to the most recent numbers, but here is what I had prior as I was trying to diagnose-
1. 73
2. 82
3. 60
4. 60
5. 60
6. 195
7. 12
8 127
9 29
10 1.4
11 2.7
12 4.3
20 6.7
21 32
22 0
23 32
24 11.6
40 164
41 91
42 104
43 152
Please note that these were before the secondary coolant pump was replaced.
At that point, I was getting a Eb1416 and a Eb1234 fault code.
I have since had the secondary coolant pump replaced and to date,do not have any error messages.
The shop that current has my car has tested the refrigerant system and found no leaks, they said the pressures were almost perfect. They said when they send power to the compressor itself, it will engage. So, they through the issue was the climate control unit, we ordered a replacement unit, but after putting it in, had the same issue. Therefore, they put the original head unit back in.
Also, the VIN for my car is WDBJF65J42B489614 if that helps with anything. I am waiting to hear back from the shop as to what the original P1/P2 values were at, but currently, they are at P1- 40 and P2- 152. The original P1 and P2 codes on the head unit were 104/152 prior to changing anything.
I will say, when I went to the shop a few days ago with the information I found from your prior help, I started the car and the engine RPM went up at idle and the fan was running, after changing the P1 and P2 codes, all was working well, but at that point, the car had already been running for a while. We also swapped one of the relays from the battery area ( I think it was for the fuel pump) with one ( I think controlling the fan) in the fuse box to the left of the engine bay (if you are looking at the car). And there was no change there.
I purchased the car from a "reputable" mom and pop dealer in town about 6 months ago, during which time it was cold outside, so I thought the AC system was not allowing the compressor to come on because of the low ambient temperatures.
I don't know if this helps at all, but when we purchased the car, there was an aftermarket radio in it that had not been installed correctly. I removed it and replaced it with the correct radio, and everything seems to be working well on that front. Also, the climate control system seems to be working well. I have no interior blower issues; the temp splits on the passenger and driver side seem to be fine, all of the flaps seem to work well, etc. The only issue is getting the compressor and fan to come on normally. I have had quite a few of these W210s and have never had this issue, so any and all help would be greatly appreciated.
Here is the issue in a nutshell-
Say the car has been sitting overnight or during the day, I would say it needs enough time to cool down, but I don't have a specific time length. Then, you get into the car and start it, and the AC does not work. It is not intermittent; it never does. And it is not temperature dependent. But sometimes you can let the car warm up for 15-20 minutes, and it will work; sometimes it won't. But if it does work, it works every time after that. You can stop the car and turn it off and back on and it will work, you can let it sit for a little while and restart it and it will work. It is very weird.
If you are in the fault codes section on the climate control head unit, it will kick the compressor on every time.
Sorry for the long message, but I wanted to give you as much context as possible. Thank you again for all of the help!"
