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2001 E320
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Discussion Starter #1 (Edited)
Hey all,

Symptoms:
Cold air from right/passenger side vents (colder from center more so than the far right), and warm/hot air from the left/driver side vents.

I have read quite a few threads regarding the A/C problems our cars have. I have pulled the sensor codes, as well as the error codes.

I have also took apart and cleaned the Duovalve (everything looked ok).

The refrigerant pressure is good (sensor code #7) at 14 bar, but where I see the problem is that the refrigerant temperature (sensor code #8) is at 132. It is the same temperature as the in-car temperature (sensor code #1).

What is the correlation between the same readings of sensor code #1 and #8, being that the refrigerant pressure is good, but the temperature is too high (hot).

Does this all make sense? It is somewhat confusing...

Almost forgot:

Sensor Data:
1. 132
2. 103
3. 73
4. 58
5. 82
6. 184
7. 14
8. 132

Error Codes:
B1227 (Outside temperature indicator sensor)
B1231 (ECT sensor)
B1234 (Sun sensor)
B1235 (Emissions Sensor)
B1423 (Switchover valve block)

Thank you,

- Cameron
 

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2007 E320 Bluetec, 2008 320ML CDI
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2,492 Posts
Confirm that the readings were with the engine running. I'd erase the trouble codes and see which return. Channel 3 & 4 have a significant difference presuming both left and right interior temp settings are the same. This is usually an indication of sticking duo valves.
Skippy


Sent from phone.
 

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2007 E320 Bluetec, 2008 320ML CDI
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Values need to be while running.

Turn on, let system settle. Maybe take a 5 minute ride and then take measurements with the engine running.

Clear the DTC's before going on the short ride.

Report back.

Fill in your location on User CP. Can sometimes help in responses.

Skippy
 

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1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
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7,035 Posts
What are the symptoms with your air con are we addressing ?
 

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2001 E320
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Discussion Starter #7
I completely forgot.

Cold air from right/passenger side vents (colder from center more so than the far right), and warm/hot air from the left/driver side vents.
 

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2007 E320 BlueTech
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37 Posts
Does it make a "hissing" sound from the vent when you turn the AC on? I experienced almost the same symptoms and did the same thing you did. I ended up taking to my Indy mechanic and he bet me $10 (and won) that it just needed to be evac'ed, ck'ed for leaks and refilled. After doing that it now freezes my elbows off..... cost was less than $200..
 

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'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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10,338 Posts
Values need to be while running.

Turn on, let system settle. Maybe take a 5 minute ride and then take measurements with the engine running.

Clear the DTC's before going on the short ride.

Report back.

Fill in your location on User CP. Can sometimes help in responses.

Skippy
When I had similar symptoms, I found it useful to first check CC readings before starting car but with ignition switch on. Under those conditions after sitting overnight, all temperatures should be close to the same. If some are more than a few degrees different, then you might suspect a bad sensor (in my case the Evap Temp Sensor was bad).

Then run or preferably drive car for 10min or so, and park (preferable outside in shade) and take CC readings quickly because ambient temperature measurement goes up quickly when car is parked and sensor picks up engine heat.

Maybe post your new readings so the experts can comment (and us owners can learn;) )
 

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1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
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Contaminated refridgerant - suggest evac and refill by a competent aircon shop.
 

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2001 E320
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Discussion Starter #11
First of all, thank you guys for your responses and time. I will do another test/sensor data check when I have some time later this week.

Contaminated refridgerant - suggest evac and refill by a competent aircon shop.
I figured it was something to do with the R134a, but wanted to be sure. It is also possible that a sensor (or two) needs replacement; I do have 174,xxx miles on the car.

Is this something I can do at home? I would rather not have to pay an indy to do this.

Thanks again. Will update soon.
 

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'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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10,338 Posts
First of all, thank you guys for your responses and time. I will do another test/sensor data check when I have some time later this week.



I figured it was something to do with the R134a, but wanted to be sure. It is also possible that a sensor (or two) needs replacement; I do have 174,xxx miles on the car.

Is this something I can do at home? I would rather not have to pay an indy to do this.

Thanks again. Will update soon.
If your tests show a need, you can easily do the evap sensor at home (do a search here), but not the evac/refill.

You could try putting in a can of R134a at home and that might get you by for a while (kit available at Walmart in USA). Lot's of guys seem to go this route for a while, but eventually you will need to get a pro to do it and determine if and where there is a leak.

By the way, I am just an owner who has been down same road.
 

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2001 E320
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Discussion Starter #13
Where is a good place to order parts like the evaporator sensor online?

Do any of you have good online stores you would recommend?
 

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2001 E320
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Discussion Starter #14
Just went out and got new sensor values and cleared the codes.

Drove around for 5 mins, got car up to temp. Stopped and took readings right away. Car was on and running.

Sensor Data:
1 - 102
2 - 87
3 - 69
4 - 60
5 - 75
6 - 173
7 - 12 or 13 (at 12, went up to 13)
8 - 125

Also, cleared the codes. When I went back in to check them all I got was E FF and then a few blank screens after that before I got back to E FF code.

Does this help out at all?

Got a quote from a respected shop in Charlotte, only $99!
 

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'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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Where is a good place to order parts like the evaporator sensor online?

Do any of you have good online stores you would recommend?
Looking at your numbers, your evap sensor is probably working OK. Only way to really check it is to take readings BEFORE you start car in morning. 1,2, 3,4,5 should be about the same (ambient temp)
 

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2001 E320
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Discussion Starter #17
Went to an indy yesterday, got the system evac'd and refilled.

The problem is still here. The air is a little colder on the left now, as well as the right, but still not blowing out cold enough air. There is actually hissing coming out of the vents when I have the A/C blowing.

Whenever I took the duovalve out to clean/inspect, it would stick a little, but I moved it around and slid a little easier.

Would this have anything to do with my problem?
 

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'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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10,338 Posts
Went to an indy yesterday, got the system evac'd and refilled.

The problem is still here. The air is a little colder on the left now, as well as the right, but still not blowing out cold enough air. There is actually hissing coming out of the vents when I have the A/C blowing.

Whenever I took the duovalve out to clean/inspect, it would stick a little, but I moved it around and slid a little easier.

Would this have anything to do with my problem?
Sounds like it still doesn't have enough refrigerant. Hopefully the Indy knew what they were doing and put in the correct amount?

I would take it back to shop because from what I have read, hissing=low refrigerant. Perhaps they put dye in so can determine if you have a leak.

If you want to check if the duovalve is part of problem, clamp off the hose that comes out of the duovalve. Take readings on CC before & after. At least that's what I did and it showed no difference.

PS: I am no expert - just another owner who has tried to work through A/C problems!
 

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2001 E320
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Discussion Starter #19
Sounds like it still doesn't have enough refrigerant. Hopefully the Indy knew what they were doing and put in the correct amount?

I would take it back to shop because from what I have read, hissing=low refrigerant. Perhaps they put dye in so can determine if you have a leak.

If you want to check if the duovalve is part of problem, clamp off the hose that comes out of the duovalve. Take readings on CC before & after. At least that's what I did and it showed no difference.

PS: I am no expert - just another owner who has tried to work through A/C problems!
Thanks.

I looked at the sensor values again and #7 (refrigerant pressure) read 15.

Is 15 a little low still?
 

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'72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
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10,338 Posts
Thanks.

I looked at the sensor values again and #7 (refrigerant pressure) read 15.

Is 15 a little low still?
I think it depends on the outside temperature and the cooling load on the compressor.

My car runs most of time at around 15 at idle, but in very hot weather (for us in Canada) I sometimes see 16-17 at idle. Under way, with low refrigerant, pressure might drop more with low fill than it would with proper fill.

BTW, I don't think I have ever seen driver side as cold as passenger side. But it is cold enough.

Good Luck with it.
 
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