[John Jackson]

Hello All. My dad picked up a new car and is going to sell his 99 E430. It has 160k miles, has been maintained, the interior and exterior are in excellent condition. He'll give it to me for $2.5k. The only issue is with the AC - if he charges it, it will work for 1 week to 1 month depending on use. After reading through these forums (and the ones at MBWorld) I'm going to head over and run the Diags from the Climate Control system and see what values I get. I'm going to HOPE there's an easy fix involving a hose or connector.

1) This seems to be a great deal from what I've read in these posts - any dissenting views?
2) What else should I check while I'm looking at the car? We have a local MB guy that's supposed to do decent work, I'll call him tomorrow (or Wednesday...it is July 4th weekend) to ask about a PPI.

Thanks

 

[Kajtek1]

You will find PPI topic in General Section.
Sounds like the AC has a small leak. When recharging it every month is an option, I would put a dye in the system and check.
Make sure it is dye only and not a "conditioner"

 

[tabijan]

While a PPI is prudent, cant you ask your dad's mechanic about anything the car needs?

I don't think ACC diagnostics will tell you from where refrigerant is leaking. An evaporator leak is a 4-figure repair so ascertain that before you commit.

Sixto
98 E320s sedan and wagon

 

[John Jackson]

My dad's mechanic will do the PPI and UV test for $200. I'm working out the schedule now. Will report back with the results.

 

[John Jackson]

The PPI and UV test are scheduled for Friday. The mechanic felt that the problem was very likely the evaporator due to the age and model of the car...he actually sounded hesitant about doing the full diag because of how sure he was that the evaporator was the problem. He also told warned me about the evaporator repair - it could take 2 days and disassembling a nearly 20 year old car would likely result in other items needing to be replaced (seals, trim, etc).

 

[Kajtek1]

Well... mechanic trying to make living on guessing is not building my confidence.

 

[JessieAMorris]

Well... mechanic trying to make living on guessing is not building my confidence.

Seriously. Until you get UV dye in it it's a complete and total guess. I've seen more failures in the schreader valves than I have evaporators. I'm pretty skeptical of the quality of work you'll get from this mechanic...

 

[John Jackson]

This guy comes well recommended by a few local MB owners...and he sells "European" cars as well. I'll let him to the PPI. I'm going to take some advice from another mechanic and go ahead and fill the system with a refrigerant that contains dye and let it run for a day or two before going in for the diagnostic. Hopefully that'll make the leak easier to find. Thanks gents!

 

[mrboca]

UV dye test is not the only test that is used. The pros use a sniffer machine. My mechanic friend has one, and it is very sensitive. Evap core leaks are easier to detect, from the water drip hole..

 

[John Jackson]

I tried to post an update with a photo - and it seems to have disappeared

I made a trip to my Dad's house yesterday. After reading instructions and warnings from these forums and a few others, I purchased - 1) A "good" pressure gauge/hose setup 2) a small can of refrigerant with UV dye 3) a larger can of refrigerant with a small amount of oil. My old man had the car running so I couldn't get any pre-crank diag values.

I turned the temperature to "Lo" and the fan to high - I couldn't hear the compressor engage. I put my head under the hood and had my Dad turn everything on - still didn't hear the compressor engage. I located what I believed to be the Low Pressure Port (driver side, halfway between the radiator and what I believe is the dryer). I put the pressure gauge onto the port and the needle buried itself in the "High" side of the gauge. I ASSumed I'd gotten a bad gauge. I decided to test it on my Camry - turned the car and AC on, hooked it up to the low pressure port (almost the same size, look, and location as the port on the Mercedes) and it read 42PSI - perfect. I went back to the Mercedes and took another reading - the needle buried itself on the High side again. I went back to the internet - everything I read indicated that I HAD found the low pressure port, and while I was worried that I'd found the High pressure port the internet led me to believe that it's hidden beneath the fan shroud at the front of the car. I did NOT want to try pushing refrigerant/dye into that port with it reading such a high pressure - I'd read enough warnings about those little cans becoming grenades and fragging fingers if connected to the high side.

So now...well...I feel stuck. I was hoping to get some dye into the system to aid in the diagnosis, but I'm not knowledgeable enough about automotive ACs to move forward.

Thanks gents!

 

[John Jackson]

https://goo.gl/photos/TbfVvyWm5iz6armTA

 

[tabijan]

You found the low side port. When the compressor isn't engaged, system pressure equalizes between high side and low side. The compressor needs to be running to get the low side lower than charge pressure in the can. Codes can still be useful if the car has been started. You'll have an indication of system pressure and whether various sensors are providing plausible values. Maybe your dad can do that for you remotely.

Sixto
98 E320s sedan and wagon

 

[Kajtek1]

Sounds like system has errors and is not engaging compressor clutch.
Do proper troubleshooting per link in stickies.

 

[John Jackson]

I'll continue through the AC troubleshooting later...here are the results so far

Code - Pre-Crank Value - Post-Crank +5minute Value
1 - 139 - 114
2 - 100 - 98
3 - 91 - 94
4 - 91 - 94
5 - 147 - 147
6 - 85 - 109
7 - 06 - 07
8 - 89 - 89
9 - 27 - 27
10 - 0.0 - 3.1
11 - 2.3 - 2.3
12 - 4.1 - 4.2
20 - 3.2 - 3.2
21 - 32 - 42
22 - 00 - 00
23 - 32 - 32
24 - 11.4 - 13.5
40 - 164 - 164
41 - 85 - 85
42 - 72 - 72
43 - 136 - 136

 

[John Jackson]

EB1 232 was the only error code. Does that mean that there's something wrong with the sensor, or does it mean that the sensor is working and reporting low pressure?

 

[mrboca]

It may mean that you are low in refrigerant. Just clear the code while in the fault code menu by pressing both AUTO buttons and holding. till you read E FF and no error codes. Take the key out, re-insert the key and start the car and check if the compressor turns with the a/c ON. You should see the hub of the compressor puller turning. If the compressor is turning, you can do the fill at the LOW SIDE.

 

[John Jackson]

I cleared the codes, turned the car back on, the compressor did turn. I connected the gauge with the refrigerant can line close - pressure started at 100PSI, I heard a click, it dropped to 75, then 50...and it stayed there...another click, the fan in front of the compressor stopped turning, and the pressure went back to 100PSI. I turned off the car, went back to check the fault codes and only got the E FF. Restarted the car, and it went through the same series of events, ending back at 100PSI.

 

[mrboca]

I cleared the codes, turned the car back on, the compressor did turn. I connected the gauge with the refrigerant can line close - pressure started at 100PSI, I heard a click, it dropped to 75, then 50...and it stayed there...another click, the fan in front of the compressor stopped turning, and the pressure went back to 100PSI. I turned off the car, went back to check the fault codes and only got the E FF. Restarted the car, and it went through the same series of events, ending back at 100PSI.

Were you able to put any refrigerant ? When it goes to 50 you should be able to put some till enough to keep the compressor running.

 

[Kajtek1]

Without proper troubleshooting my crystal ball tells your system has overcharge.

 

[John Jackson]

Were you able to put any refrigerant ? When it goes to 50 you should be able to put some till enough to keep the compressor running.

I did my best. Once the pressure dropped to 50 I opened the refrigerant line and the can got cold. It only lasted a second before the compressor stopped and the pressure went back up - I'm wondering if whatever went in got squirted back into the can. My goal was to TRY and get some dye into the system before tomorrow...but I'm pretty sure I just got some dye on the side of the engine well. The appt is tomorrow at 11. Hopefully the PPI will come back with good news, and the AC problem is just a sensor *fingers-crossed*