Tall Giraffe

2001 E55 AMG

So I have been kicking the can down the road with my A/C and now its time to address. I have been reading incessantly about this topic and feel I have a good grasp but you can never learn enough through others' experiences.

To start I also have cooling issues to which I have discovered my fan clutch is dead. I have one on order as well as a radiator because mine sprung a leak in leu of the clutch probably causing too much pressure.

Next, I'm sure I have a slow leak and my compressor is beginning to rattle. Since I have a bent radiator support, I want to change the Condenser, line to dryer, dryer, compressor and Expansion Valve while straightening the support. I am considering flushing lines (maybe evap) and replacing as many O rings as I can reach. Finally the Aux fans don't spin on their own but do when manually controlled by Climate unit.

I recently charged the system for this year and here are my results from the diag after the car has been running.

Results from a 94 degree day with 54% humidity

1=98
2=141
3=60
4=62
5=39
6=188
7=20
8=127

No error codes.

Here are a couple of pics from my passenger side footwell peeking in behind the vent. I have been told that this is the evap drain hose. It is moist on the inside or according to the pic the left side of the hose. doesn't squeeze green however. I have not hit it with a black light as I just found it. Thoughts on this? No green leaks on the ground below or very little condensation drip I have ever noticed. Center vest has hissed on low pressure but now sounds like a nebulizer that goes off and on when AC is on. Indie says he could never find leak with sniffer in vents or underneath, but that is what he says.





Questions:

1). Does the fan clutch have anything to do with the Aux Fans not working or is that strictly an AC issue. Swap on Fan Controller yields no different results.
2). What other signs can I look for about a possible evap failure
3). What are my diag numbers supposed to read?

Brand

4). For Compressors I find the Denso, Nissens and Sanden Behr. Is there a difference? Sanden is so inexpensive

Sanden Behr has the following notes under Application Notes -

"Aftermarket replacement manufactured by Sanden-Behr, this compressor replaces the Nippondenso 7SB16C, which was replaced with the 7SBU16C. Original Denso units have a high failure rate. The cause of the original failures are discharge reed valves breaking in the bottom-most piston cylinder. The main symptom of this failure is the compressor not pumping, because of internal pressure bleeding between the suction and discharge sides of the compressor. This breakage can also cause the pump to 'lock up' if metal gets wedged in the cylinder walls, and can cause condenser restrictions."

:http://www.techchoiceparts.com/inven...-ac-compressor

5) if radiator is Behr why would a compressor be any different from condenser?

6) if I flush the evap, would I add additional oil to the system via compressor? Or do I need to

Thats all for now. Please let me know if I missed anything you need

Thanks in advance

TG

Plutoe

I will answer some of your questions and leave the rest to our resident HS artist------1=no, 2=concentrate on the problem, number 5 evap should be 39-41,yours is doing fine, 3 see the stickies for the detail, however your number 2 indicates you have a faulty outside temp sensor and although we have one bone head that poo poo's the sensor--the correct outside temp provides input for the AC to adjust fan speed-----7=20,your compressor makes great pressure------overall I think your have good numbers,but will you get the same numbers in a week or month only you can tell us.

Tall Giraffe

Thanks for the input Plutoe. I was expecting and ready to post my VIN

In reading past threads perhaps you may be referring to the sun sensor for fan speeds? I did get a sun sensor error (B1234) the first time I ran diag but I reset the code and it has not come back. Diags gave me 3.7v for value 12. I think the reason my external temp is so high in this case is because of 2 things. 1.) I was sitting in a partially shaded parking lot performing tests and 2.) the radiator is putting off a lot of heat and since my fan clutch is dead, the heat from the radiator is altering my temp. The dash gauge is working properly even when the diags calls it 141 degrees. When I disconnected it, it read E on diags and -36 in dash. I cleaned it as well as the contact and reinstalled. It does go down when I start moving.

I agree with long term numbers but since my compressor rattles, I want to be proactive.

Tall Giraffe

More numbers

87 degrees with 69% humidity

Cold engine no start

1. 89
2. 85
3. 84
4. 84
5. 80
6. 84
7. 6
8. 82
20. 3.2 (ma?)

Idle 5 min

1. 87
2. disregarded
3. 55
4. 51
5. 57
6. 184
7. 16
8. 139
20. 12.7

Idle 10 min

1. 85
2. disregarded
3. 58
4. 58
5. 58
6. 193
7. 17
8. 141
20. 6

So #20. is AUX fan control. At a resting state, I get a live reading of 3.2 when I override the AUX with the Climate control (holding down both autos for 10+ second), I get full fan speed at 21 (21ma i suppose). after idling and at operating temp, when I increase the RPMs to 1500, the value increases to18.1 and the fans do spin.

#10. blower control voltage. I think there is 7 speeds to blowing the air. Here is how my voltage stepped up while increasing fan speed. LOW 1=.8, 2=.8, 3=1.3,4=2, 5=2.7, 6=3.5 and 7=6 volts HIGH

Im a little concerned as to why my evap temp and cores increased to 57 degrees. Is this a bad thing?

Plutoe

I wish you data nuts would remember how easy it is to compare spreadsheet display data------for my analysis the only important numbers are 5,7 and 8 and based on your data the only this time problem is 5 a poorly functioning expansion valve----will it be consistent---you tell us

Tall Giraffe

Thanks again! yea I agree xls would of been better in this situation though I hadn't planned on posting so much data. Some of the other data is to help others with AC related system questions. I had to read *** hundreds of threads to get somewhat of a clue so hopefully this will answer simultaneous questions for others I know I had.

Its not consistent.

While driving today I pressed REST for 5 sec to turn on the data "live" here is what I saw. 93 degrees @1500 rpm with stop and go traffic

5- stayed around 40 while on the move and stopped
7- drops to about 11-12 while on the move
8- drops to 111-118 while on the move

When at the light

7- goes up to 16
8- goes uo to 132

Makes sense cause as the rpm drop below 1500, I hear the compressor rattling harder probably not producing enough pressure until i get moving again from a stop.

Maybe the expansion is ok and my hope is that the evap is leak free too.

kajtek1

What is your complain?
Per the numbers your system is working fine. Maybe not the greatest, but good for old car.
The only thing you might want to recheck is refrigerant pressure. It should go to at least 18 and on hot day above 20 bars.
Next time you enter car in hot afternoon - display #7 , drive with it and tell us the highest number you record.
Also what is the deal with exterior temp sensor errors?
To prize you - the first guy ever who did his homework and do full troubleshooting before making 20 posts with inadequate data

Tall Giraffe

So today I traced a pattern. 95 degrees out

Sensor 3, 4, 5 stay near 40 when I'm at a stop at a light. Sensor 7 averages 16-18. Sensor 8 is about 132-140

When I'm driving 3, 4, 5 rise to about 55. Sensor 7 drops to about 11-12 when at a constant RPM of 1500. Sensor 8 is about 111

Then the compressor rattling gets more intense until i stop at a light and pressure goes up. Also will have hiss from center vents especially with lower pressure. Faint to none when pressure goes up.

I still think that when the car stops, since my fan clutch is broken and the fan not dissipating the heat, I think my sensor is picking up the heat and registering it. When I am on the move it goes back down to normal.

14 years on the forums and my first award! I don't post much but when I do, I post quality. LOL


I had the compressor changed a couple of years ago when that failed. I believe the drier and hose was also done but not the condenser nor expansion valve. I still need to do a fresh freon leak diagnosis before replacing parts but....

Could the drop in pressure be from strictly from a failing compressor or could the condenser/ drier be clogged too?

Should I replace the expansion valve even though the numbers are not that far off?

Should I flush the evaporator?

Should i replace the pressure sensor for good measure?

kajtek1

Variable output coordinated with 7 or more sensors reading is hard to troubleshoot in small issue you have.
So once again - you system works period. Pressure it tad low, but I would still spend more time on troubleshooting before adding more refrigerant
Focus on #5 evaporator temp and #7 the pressure.
#5 on hot cabin should stay about 2C or 35F. It will go up when the cabin gets cooled down.
Bad fan clutch should not affect AC unless the engine overheats, than the computer will shut the AC down. So are the electric fans/fan working?

kajtek1

After sleeping on m last reply- I did not make it clear.
The only way your AC output gets lowered is when computer is getting signal that something is out of operating parameters. Like is your engine #6 getting hot when cruising at 1500 rpm? What is #2 showing at this moment?

Tall Giraffe

To answer post #9, about the fans, yes the do work. I have seen them physically turn when I was performing the idle tests in post 3 and the read out for sensor value 20 does increase as well while the AC is operating so Im pretty confident they function. Today I saw that number rise to 18.1 (21.1 I have seen as the high) and it was about 98 here today.

You mentioned "#5 on hot cabin should stay about 2C or 35F. It will go up when the cabin gets cooled down."

Thats not the case I see. Mine starts about 75-80 and gets no lower than 40-42 and it seems to stay not go up when cool while the cores floats near the same value. Now at night, that is a different story, it does stay in the mid to upper 30's.

Sensor 7 again drops to about 11 under load and at a stop light recovers to about 17. When it drops, I feel the struggle from the system.

Post 10.

Again its the a little opposite. Since my fan clutch is out, I cool on the move but the heat rises at the stops. On the move, Sensor 2 gets within 5-10 degrees of actual exterior temp until I stop then it goes up depending on how long I am sitting. I do feel again because the radiator fan is not functioning to pull the radiant heat away and that sensor is picking up the temperature reading. If this does not go away when I replace the fan clutch, Ill replace the grill thermometer.

I have an off and on center vent hiss. It intensifies when the pressure drops. but sometimes goes completely away or so faint that one has to place the ear to the vent.

So I agree with you that the system is working (although not 100% efficiently) but the more this gets discussed and the more I read, here is what I think.

My compressor rattles. I know I also have a small leak. I am starting to feel there is also a possible restriction and/or weakened compressor. As far as I can tell my condenser is original and has been kept during a few total leak outs during the winters and a compressor/drier change 2 years ago since I have owned her.

It will blow cold air, eventually. Like today it took about 20 minutes of driving to get 3, 4, 5 to be near the 40's range. But it was also 98 degrees. Still, while I understand that the fan clutch does not have a direct role in the AC system, I feel like not pulling heat from the radiator puts more pressure on the condenser to extract heat from the refrigerant.

kajtek1

FYI I drove E300 DT with engine fan removed for few years. That was in California and Las Vegas, where we had 114F .
Now the new owner in Los Angeles area (who did not trust the idea at the beginning) removed the blades again.
So if your engine does not overheat - the engine fan is optional. It is electric fan/fans that make air flow at the condenser.
Coming to your situation, at this point I would put a can (12 oz) of R134 into the system. If you suspect leak- make it can with dye but nothing more.

Tall Giraffe

So I placed my fan clutch in today and now my engine temp stays below 190 as before it was rising up to about 210. You can hear the whoosh from the fan when I take off. That's better. The thermometer however still rises upwards of 140 at a stand still, when I'm on the move it goes back to normal. The dash thermometer stays about right within 2-4 degrees.

Tall Giraffe

If these drain hoses has dye in them, is this a sure sign the evaporator has a leak?

Where else should I check for leaks on the evap with a UV light aside from underneath?

Tall Giraffe

As an update, the compressor clutch continued to rattle ultimately leaking all refrigerant when the car was off and in the end the evaporator was the ultimate issue.

With dye in the system and black light, the rear compressor seal showed to spray dye. I decided to then rebuild the system. I always suspected the evaporator to be the problem but started from the front to back since I was determined to work with clean new system since parts were relatively cheap and I was doing the labor. Items replaced- the condenser, compressor, expansion, dryer, all o rings new oil and flushed the lines and evap in car.

After replacing the parts, the last step was flushing the evap, When flushing, it built pressure and blew out a ton of sediment which in the end turned out to be stop leak. At the time I was optimistic pulled vacuum but it would not hold. Then out of the driver drain, green dye dropped confirming evap failure. The job I feared doing needed to be done.

So I replaced the evap. As you can see dye was seeping out of the driver side of the evap.





The evap job was truly not difficult one IMO. Just venturing into the unknown the first time was intimidating. The pelican parts guide helped generally. At least it was not a dirty one but was tedious with documenting how things went back together, not misplacing where screws went and mostly taking care not to break fragile connectors ( *** EIS ignition! ) or plastic pieces- which A pillar and knee guard clips did break no matter how careful. I lost one screw out of the entire job. I was also nervous in and around the air handler box, heater core and air driven tubes and actuators. Took me 3 good days, taking my time, cleaning and running into small impasses. I replaced the drain hoses with clear vinyl so I can see in the future if my evap fails again. Replaced dryer again after system was opened again.

The end result

Sensor values on the move - in F

2- 80
3- 40
4- 40
5- 35
7- 9

at cold start up, my 3, 4, and 5 are at or near ambient temp and 7 is at 5.

I feel like 7 range is running slightly under specs but blows cold. I do hear when the expansion cycles for a couple of seconds of hiss. Could it be slighty low still?

7 value ranges from from as low as 7 to 16 depending on temp. At 70 degrees on the freeway, I saw 7 fall to 6.

Coolling

Also replaced the radiator and flushed the system using distilled water exchange method. Now she is all blue. Had to top off from he loss of coolant during the evap exchange as the heater core will leak out coolant and hoses connecting will too.

Still not running a fan clutch yet since every one I get arrives engaged. I may try Meyle before I go Sachs

kajtek1

WOW.
The evaporator job is estimated at 20 + hr for good mechanics, so you saying it was not too difficult sure brings some question.
I no longer own W210 for for other friends would you mind to spill some details?.
Coming to measuring refrigerant pressure #7 is to do it at max output, what should bring it in 20's of bars.
My best way is to leave the car park on the sun and enter it with very hot interior,
At this moment when you start the engine, AC will be at max for at least couple of minutes.

Tall Giraffe

WTF!!!

I'd be happy to share details about the evap replacement. Fire away any specific questions.

Don't get me wrong its not an oil change by any means. It requires strategy, organization, space and patience. For example, the EIS key module had 4 different wires that plugged in the rear and the pelican guide mentioned nothing other than disassembly but the wires have different removal methods, The ring that goes around the ignition should come off first which is done by turning/spinning it- if you can, Freeing the ring allows you to free the ignition turn it around and remove the wires but when it is still attached to the dash, its not so easy. You have to bend your hand backwards behind the dash and feel. This stalled me at least an hour and there is no way to understand the solution other than experience after the fact. The air handler removal and evap replacement was the longest part.Tons of screws, clips, and careful removal of actuator arms needed for space to open the handler.




That being said, If I were to do it again , I could probably shave the time in half potentially.

As far as #7, when I do what you mentioned I max out at 16.

Does it need more refrigerant? Could it be that since the system is so new and I have the newest compressor, that it just runs efficiently at less load? It blows cold and the 3,4,5 numbers seem good....

vinceC

The only way to truly know if you have the correct charge is to charge by weight. Hopefully you evacuated the system to remove any air (moisture) before recharging. The correct charge is 34.8 oz..

kajtek1

16 bars max is on lower side, but having small leak that was what I was charging to and it was freezing my elbow. High limit on my car was 32 bars for referral.
What is #5 temp at full output? When it is just couple degrees above freezing, you have good working system.
Have never seen car with such job in real life, but common impression I hear is "somebody drop a grenade in it"
Your picture confirms that

Tall Giraffe

yes I did evac for more than an hour and it held -27 inch for another hour. Weighed out to ~35 oz. Just seems odd that my system runs at bar pressure lower than others' posted numbers,

vinceC

You have touched on a point often overlooked in these conversations, i.e at rest or moving and ambient temperature.

First, your charge is fine at 35 oz. Don't add more.

On a system recently evacuated and recharged, good compressor, clean condenser, ambient temp around 70F, at rest, I typically see 16-17 bar on the high side (#7). On the road the high side pressure drops, largely due to increased airflow over the condenser. I see anywhere from 5-10 bar depending on speed, ambient, etc. You can watch it on the road, speed up #7 drops, come to a stop #7 rises. Also, 3,4, and 5 rise and fall a bit. I find it more useful to watch them over a period during on road driving. Plutoe's numbers are good, but don't panic if they rise a bit higher at times. And fix the outside temp sensor.

Tall Giraffe

Thanks for the feedback. After a couple of days of monitoring, this is exactly where ranges are on my newly replaced system sitting and within 80-90F ambient temp on the move. Rarely my 3 and 4 rises into the 50s but dives when on the move.

Also my outside temperature sensor at the time of posting originally was disconnected thinking it was abnormal. I have tried 3 different sensors (one new) and they all are on point when moving but race up to what I think is due to radiant engine heat (sometimes to 130F) when sitting still long enough.

This has been quite an experience replacing the whole system front to back, now on to the next project!