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AC cool but not cold plus

8K views 42 replies 8 participants last post by  Braveheart007 
#1 ·
So I have just bought a E320 1997

have read al the AC posts but havent seen any challenges like mine with high pressure...

It has had a new compressor and dryer fitted a year ago.

AC on low max fan air blows hard and fast and it is not freezing as it should it is a lets say "cooler" than ambient but only just... need to open window or you get all clammy.

anyway thought it might be low on R134 .. got a can with gauge .. says set the "V" to the ambient temp (DONE) start car low temp full fan as per can. (DONE)


Connect can/gauge and it is in the RED can says if it is higher that the 'V" do not fill up.

so carried out the Diag via the climate control head.

values are as follows:

1 30
2 24
3 37
4 36
5 33
6 89
7 7
8 37
9 0.5
10 3.5

Aux fans working OK
thought it would be a case of topping up gas but concerned dince it was in the RED on the gauge.

Any thought?

many thanks in advance.
 
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#2 ·
If this is your first Benz, I would strongly advise that you read the AC section of your owners manual. The AC systems design is very different than what you may have previously experienced.

Additionally you provided the actual value test result, what about the faults if any??

In any event the data suggests that you need refrigerant and you are in a metric country. Is that correct
 
#3 ·
I am in Los Angeles....I ahve read just about all of the threads all 51 pages but havent seen one with my challenge as sorts.

i would have thought the REFRIG was low but got thrown off with it showing HIGH on the gauge.

Think I should fire some gas in and see what happens???

thanks
 
#5 ·
Check for erros codes:

http://www.benzworld.org/forums/w21...-climate-control-diagnostic-trouble-code.html

I would suspect you have a small leak - and that the refridgerant is contaminated. Forget 9, and 10 just shows your fan on low setting.

I would suggest you spring for a $80 evac/refill at any competant air con shop, the evac would show any major leak, and you would have a 100% fresh and proper charge.

It's interesting the reapir work last year didn't mention a expansion valve change, with a '97 that would have been prudent - but if you opened the systen back up now (new expansion valve and new dryer) that would be around $90 or so in additional parts on top of the refill.
 
#7 ·
It is not the charge, you are going down the wrong road.
Get the codes, and post them here, and verify what led your car to have non US parameters set in to the AC controller.
The diagnostics in the W210 leave little or no guess work.
Get the facts before you start random repairs/recharge.
 
#8 ·
Ok checked the codes and this is whats showing

Eb1 232 Refrigerant Pressure Sensor (B12)
Eb1 234 Sun Sensor
Eb1 235 Emmission Sensor (B31)
Eb1 419 Electromaqgnetic Clutch (A9k1)
Eb1 459 Series Interface (H2) connection to instrument cluster (H1)

E FF

Wondering if the guy that repaired this never cleared the coded.... the woman hasnt driven the car since it was repaired.. just started up to keep the battery topped up.

I have a funny feeling the evaporator might have been changed too as i am finding the lower drivers dash and glove box a little loose.... but maybe not.

I know for sure the compressor and the dryer have been changed.

Appreciate all the help
 
#12 ·
Ok checked the codes and this is whats showing

Eb1 232 Refrigerant Pressure Sensor (B12)
Eb1 234 Sun Sensor
Eb1 235 Emmission Sensor (B31)
Eb1 419 Electromaqgnetic Clutch (A9k1)
Eb1 459 Series Interface (H2) connection to instrument cluster (H1)
232 This can happen when the system was recharged.

234 All most every W210 has this fault every time you check
.
235 If this sensor was disconnected & reconnected it will throw a fault.

419 This is your problem, check to see if the compressor is engaged.

459 Not sure what this is other than a loose connection.

So clear the codes and try to run the AC again,
While it is running check the compressor to see if it is turning (the forward part of the pulley should be turning).
Then check the codes again, let us know what you have.
 
#11 ·
I would recommend clearing those codes, and having the refrigerant extracted and refilled to exact specifications. Then check the pressures against the table.

I would not recommend running the system in its present condition. Low refrigerant level or flow means low oil migration, which dramatically increases compressor wear.
 
#14 ·
Ok so here is the latest:

found how to clear codes... cleared codes.

only one code remaining E FF

I have just came in from the store and I switch on AC ... there is a distinct heat coming through.

AC compressor switches on no problem .. even switch off and on a few times to double check.

pass side seems cooler ... drivers side definately a warmth coming through.

Could the AC actuall be ok and it is the Duo Valve??
 
#15 ·
so carried out the Diag via the climate control head.

values are as follows:

1 30=86 in car temp
2 24=75 outside air temp
3 37=98 left heater core, high/over ambient
4 36=96 right heater core, high/over ambient
5 33=91 evaporator temp too high, should be 42-46
6 89=192 engine temp, ok
7 7=101 psi of R134 this is enough to get some cooling
8 37=98 refrigerant temp too low should be 100-160
I made some notes, it looks like your duo valves are slipping some heat to the heater cores. I would start there.
It also looks like the compressor is not running as the evap temp is too high and the referig temp is so low.
 
#16 ·
Appreciate the follow up .... Just went another trip and the drivers side does get cooler ( but not AC cold ) when driving and seems to warm up a bit when idle etc.

Compressor definately coming on for sure 100% ... will try the duo value and see what transpires from that.

thanks for now...
 
#20 ·
ok so cleared the codes ---- removed top off the dual valve -- didnt have the dual rubber gasket type ---- just 2 silver plungers ---

Anyway removed cleaned and cleaned the value seats too .... little smear of petrolium jelly and rebuilt.

when driving it does seem a little better on the drivers side -- but tends to go a little warm when at idle---

going to get the system vac and re-filled and see if it is any better.... will give up date soon.

of course i can only get that done when i get this abs/etc/bas light and limp mode removed... geez
 
#21 ·
oK SO AS PER MY OTHER THREAD etc/abs fixed !!!!

No just to get this AC done.

Duo valve cleaned and lubed.

still getting a distinct warmth through the left side vents.

noticed when i was on the highway it started to get a little cooler .. not freezing but a lot cooler than it has been for sure.

when i come to idle .. traffic etc ... it gets a little warm again.

sysmptoms of an evap temp sensor???? any one have a the part number?

1997 E320

thanks
 
#23 ·
UP DATE ON THE AC:

AFTER THE TRANS GOT REPAIRED LAST NIGHT... TOOK IT A 240 MILE ROUND TRIP TO SANTA BARBARA .... ZERO PROBLEMS......

THE AC SEEMED TO BE WORKING NOT TOO BAD .... NOT FREEZING COLD BUT COLD.

DECIDED TO CHECK THE REFRIGERANT ---- WENT TO 4 PLACES ALL BUSY ---- PULLED INTO PEPBOYS AND GOT THE R134 GAS COMPLETE WITH GAUGE.

CAP OFF LOW SIDE AND CONNECTED HOSE ---ENGINE RUNNING --- MAX FAN --- BOTH SIDES LOW --- AUTO ,ON THE CLIMATE CONTROL HEAD---

GAUGE READS 45LBS -IN THE RED ZONE--- COMPRESSOR RUNNING ---- PRESS EC ----- COMPRESSOR STOPS RUNNING --- PRESS EC COMPRESSOR KICKS IN.

WHEN I GO SLOW AROUND TOWN .. TRAFFIC LIGHTS ETC .. THATS WHEN THE LOOK WARM AIR COMES IN --- ALREADY DONE THE DUO VALVE.

BUT WHY WOULD THE PRESSURE BE SO HIGH.. BUT NOT COOL ALL THE TIME?

COULD IT STILL BE LOW REFRIGERANT ??
 
#25 ·
I think he refers to low side pressure, where 45 lb on running compressor is on high side.
Since he never checked the high side on the clima display, I believe that he overcharged the system and high limit switch kills the AC at 32 bars.
So Braveheart007 -after entering sensors on clima display -scroll to value 7 what shows the high side pressure in bars. If you peak above 32 bars, you need to let the pressure go.
 
#29 ·
You still need know how to use it ;)
That gauge should be read with compressor running at full blast. Since your car has variable output compressor, you don't have easy way to say if it is running at full output.
I never pay the attention to low side when I fill up my system. The car has high pressure displayed conveniently on the LCD, so why not use it?
 
#31 ·
Oh, you have one of the cans of R134a++++ with a "made in china" plastic gage.
Most of those make claims that their 134 formula works better than normal 134 and also has the benefit of a sealer to stop any leaks you may have.
I would never use any of those one can wonders with sealer.
The 50 psi you see on the Low side when the AC is running is to high, now this can be false reading of the china plastic gage or the scharader valve connection has a problem and you are seeing can pressure not low side pressure.
The values you posted show the heater cores are cooler now and the evaporator temp lower the high side pressure is higher and the 134 temp is higher, all indicate the charge is low.
You have stated that the electric fans work, I don't know how, because the High side #7 needs to be at 15 for them to start, and you only have 7-8.
You need a real set of gages and can tap and a can of R134a or take the car to some one that has these items.
The best would be to take it to a AC shop to have the system evacuated (tested for sealant) and recharged with 2.2 pounds (check that amount) of R134a
If the system has sealant in it, this can cause all sorts of prolems. One is that the expansion valve is stuck open.
 
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