A/C oil/flushing A/C
08-23-2015 | 12:44 PM
#1
Thread Starter
Junior Member
Joined: Feb 2009
Posts: 34
Likes: 5
2004 E55 AMG
A/C oil/flushing A/C
So, I've been having issues with poor A/C performance. I got may DAS system in, and have been digging into the parameters on the car. So yesterday after reading up on a lot of information here, I decided to run some experiments.
I set up with DAS going into the A/C section, compressor actuations. I manually turned on the compressor to 70%, put the A/C into manual max cool on the dash console.
From DAS, I watched the parameters, and connected my gauge set, as well as my thermocouples to get temperatures off the low and high side tube in order to calculate supercooling.
I removed a small amount of freon to monitor the performance numbers, then added a small amount of freon and wrote all these numbers down. In doing so, I noticed that I have an oscillation on the evaporator temperature, on the order of about 2C amplitude in 90 second period. And my evap temps are in the 20C range, which is really terrible.
So, my thought is that the duovalve could be oscillating. I've ordered the part and will swap that out in a couple of days.
But, to my subject. I noticed that there seems to be a lot of oil in the freon, and I can't help but wonder if someone overcharged the A/C with too much oil. I've read up, but am getting conflicting information on if it's possible to remove the oil from a system without taking it apart. It seems like using an A/C flushing agent will get the oil out, but some people indicate that you should never flush the compressor.
What I really want to do it get the system evacuated from all oil, and all r134a, then have it recharged with the correct amount of oil and r134a. Is this possible without taking things apart?
I hate the thought of people taking things apart, because it's sort of working now, and once you go into something odds are that something else will get broken or not properly reassembled.
I set up with DAS going into the A/C section, compressor actuations. I manually turned on the compressor to 70%, put the A/C into manual max cool on the dash console.
From DAS, I watched the parameters, and connected my gauge set, as well as my thermocouples to get temperatures off the low and high side tube in order to calculate supercooling.
I removed a small amount of freon to monitor the performance numbers, then added a small amount of freon and wrote all these numbers down. In doing so, I noticed that I have an oscillation on the evaporator temperature, on the order of about 2C amplitude in 90 second period. And my evap temps are in the 20C range, which is really terrible.
So, my thought is that the duovalve could be oscillating. I've ordered the part and will swap that out in a couple of days.
But, to my subject. I noticed that there seems to be a lot of oil in the freon, and I can't help but wonder if someone overcharged the A/C with too much oil. I've read up, but am getting conflicting information on if it's possible to remove the oil from a system without taking it apart. It seems like using an A/C flushing agent will get the oil out, but some people indicate that you should never flush the compressor.
What I really want to do it get the system evacuated from all oil, and all r134a, then have it recharged with the correct amount of oil and r134a. Is this possible without taking things apart?
I hate the thought of people taking things apart, because it's sort of working now, and once you go into something odds are that something else will get broken or not properly reassembled.
08-23-2015 | 03:27 PM
#2
Senior Member
Joined: Jun 2014
Posts: 471
Likes: 32
W211 E55 2003
Take it to a shop that does AC service. They have a machine that theyll hook up to the car, and its going to empty the system from r134 and the oil. Then it de-pressurizes the system and creates vacuum to check if anything is leaking, and after that its going to refill you AC. The tech is going to setup the machine to fill it up with the correct amount of r134 and oil
08-23-2015 | 04:12 PM
#3
Super Member
Joined: Jan 2007
Posts: 852
Likes: 3
From: Sleepy Hollow, IL
65 Chevelle Wagon w/ C5 frame, 08 ML63, 04 S600, 04 E55,(sold) 00 ML55,(sold) 98 C43-55K Swap
Take it to a shop that does AC service. They have a machine that theyll hook up to the car, and its going to empty the system from r134 and the oil. Then it de-pressurizes the system and creates vacuum to check if anything is leaking, and after that its going to refill you AC. The tech is going to setup the machine to fill it up with the correct amount of r134 and oil
it's probably a 1/2lb low or so.
