Strange A/C operation

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eralimited57

2008 Sprinter 2500 170 Extended High Top 3.0L CRD
2008 NCV3 3.0l diesel 59k miles.

Driving down the road, with A/C set to max temperature and fan on high, all three left vents (driver's side) blow air that is about 12F warmer than all three (passenger) side vents. When I come to a stop both left and right side vents rise about 10F. This morning in Dallas it is about 80F. At stop the left (driver) side vents blow at about 70F and the right side vents at about 55F. When driving at 50 mph.the driver side vents blow at about 12-16F warmer than the passenger side. The passenger side is always colder than the driver side vents. I read some other threads about this and they recommended setting the temperature dial to 70F and full fan setting to prevent freeze up and I tried that but it made no difference. The only thing I had done between when I remember it working ok is that a new radiator clutch fan was installed at Linden (Dennis). My old clutch fan was leaking oil and not cooling going up grades. I should also mention that yesterday morning after I made a stop the air coming out of the driver side blew only for a short time at 40F!!!! Both electric cooling fans are on when the A/C is on. Dennis just did a full onboard diagnostic with his scanner and no fault codes are present and no CEL is present either. What could be going on here? TIA.
 
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2

220817a

Independent & Self Reliant - From Chattanooga TN
eralimited57 said:
2008 NCV3 3.0l diesel 59k miles.

Driving down the road, with A/C set to max temperature and fan on high, all three left vents (driver's side) blow air that is about 12F warmer than all three (passenger) side vents. When I come to a stop both left and right side vents rise about 10F. This morning in Dallas it is about 80F. At stop the left (driver) side vents blow at about 70F and the right side vents at about 55F. When driving at 50 mph.the driver side vents blow at about 12-16F warmer than the passenger side. The passenger side is always colder than the driver side vents. I read some other threads about this and they recommended setting the temperature dial to 70F and full fan setting to prevent freeze up and I tried that but it made no difference. The only thing I had done between when I remember it working ok is that a new radiator clutch fan was installed at Linden (Dennis). My old clutch fan was leaking oil and not cooling going up grades. I should also mention that yesterday morning after I made a stop the air coming out of the driver side blew only for a short time at 40F!!!! Both electric cooling fans are on when the A/C is on. Dennis just did a full onboard diagnostic with his scanner and no fault codes are present and no CEL is present either. What could be going on here? TIA.
Click to expand...
Reset the adaptation/calibration of the blend door actuator.
 
L

lindenengineering

Well-known member
AND
Check the refrigerant charge.
All MB products including passenger cars have odd evaporator outputs when the charge is low..
Remember A/C systems lose about 5% of charge per annum.
Yours might be ready for a recharge and new charge valves.
Dennis
 
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eralimited57

2008 Sprinter 2500 170 Extended High Top 3.0L CRD
lindenengineering said:
AND
Check the refrigerant charge.
All MB products including passenger cars have odd evaporator outputs when the charge is low..
Remember A/C systems lose about 5% of charge per annum.
Yours might be ready for a recharge and new charge valves.
Dennis
Click to expand...
Hello Dennis, great meeting last week at your shop. Got home just fine thanks to your help while on my trip.

Question I have is can I check the level myself with one of those DIY cans of R134 with the gauge on it that the auto parts stores sell or if that's not the right approach where do you suggest I take it, MB Sprinter dealer or independent Sprinter repair or ???
 
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eralimited57

2008 Sprinter 2500 170 Extended High Top 3.0L CRD
Here I found an old post from Dennis...........

"Classic MB issues, check and verify A/C charge FIRST
Then if the issue still exists scan diag, for a blend door actuator motor stuck /faulty or it needs re-calibration.
Factory style scanner required,

Dennis you and Delvin drove my Sprinter last week using your scanner and did not find anything so it leads me to believe that the door actuator is functioning ok??

Remember the dark grey long wheel base, high top - clutch fan, fuel leak issue van my first name is Lee
 
2

220817a

Independent & Self Reliant - From Chattanooga TN
eralimited57 said:
How do I go about doing this? I have an Autel 808 pro if it can be done with that or ??
Click to expand...
I don't know much about your scanner, but you need a scanner that has the capability to communicate with KLA (Climate Control Module) and has the option for resetting the adaptation of the blend door... Get yourself a set of the guages for the A/C system and measure the pressure on both ends ( High and Low).... With the engine and A/C on, depending on the outside temperature, you should have L - 55 to 60 psi max and H - 200 to 300 psi.

See the pictures down below...
 

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eralimited57

2008 Sprinter 2500 170 Extended High Top 3.0L CRD
What refrigerant should be used. Sticker says R134a max. Is that the same as what is sold at AutoZone and OReilies as R134?
 
L

lindenengineering

Well-known member
Advise
DO NOT GUESS IT.
The modis operandi is to evacuate it,
Replace the two charge valves, and draw the system into a deep vacuum for at least 20 minutes (28 to 30"HG) .
This will cause any moisture dwelling in the system to boil out at a 28 to 30" HG depression .
Then charge with 1,72 lbs of filtered refrigerant, then test for leaks with a leak tester .
Dennis
 
2

220817a

Independent & Self Reliant - From Chattanooga TN
Good advice... But I would still reset the adaptation of the blend door and check the pressure first before doing a complete evacuation/vacuum/charge.
 
2

220817a

Independent & Self Reliant - From Chattanooga TN
Also... Turn from cold to hot and monitor the activity of the blend door.
 
E

eralimited57

2008 Sprinter 2500 170 Extended High Top 3.0L CRD
I tried this and when turned to hot, the air temperature from all the registers gets hot air fed to them as they should. I don't know how else to monitor the activity of the blend doors other than just monitoring the temperature coming out of the registers.
 
2

220817a

Independent & Self Reliant - From Chattanooga TN
eralimited57 said:
I tried this and when turned to hot, the air temperature from all the registers gets hot air fed to them as they should. I don't know how else to monitor the activity of the blend doors other than just monitoring the temperature coming out of the registers.
Click to expand...
By %
IMG_20210905_0005.jpeg
 
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