Red_Bean_Bun
Well-Known Member
Other than changing your aircon filter, there are tasks that one should do at least every 2 years for your aircon. What I read from the manual is that BMW would test if there is a loss in the weight (sic!) of your aircon's refrigerant and compressor oil.
Most of the articles I read are focused on the the low pressure and high pressure readings - I am still trying to correlate the relationship between BMW's weight approach versus pressure. See this - pic compliments from Daz3's ride and should be found under your bonnet if it hasn't been replaced like mine .....
View attachment 61144
Notice how it says 590 +- 10g as in BMW expects a variance of 10g for 590g of r134a refrigerant. And BMW also expects that in 2 years the variance would widen to 20g and at this point a recharge is needed.
So I set about figuring how do I add 20g of r134a back into the ride (assuming it lost 20g in the last 2 years). Most of the DIYs are about squirting the freon and stopping only when it hits a certain pressure. While it worked for some people I had feedback that it screwed a number of rides as well. Since BMW's approach is based on weight - I reckon that that approach is the correct approach and I decided not to recharge my aircon gas from a can of r134a.
There are 2 reasons -
- BMW did not do it that way
- A universal recharge by pressure approach by assume all car have an LP of x psi does not sound logical. How can all
cars be the same.
So I decided that I need to find the equivalence of the same aircon machine used by the BMW dealers to replace the freon and compressor oil. I started with Bosch since they are a major supplier of technology for BMW. And stumbled on to the AC 650. I decided to read the technical manual and found this -
View attachment 61145
View attachment 61146
The AC 650 apparently has a database of BMW vehicles and it is able to use this information to charge the r134a and the compressor oil with the right weight and viscosity.
So I decided to look for a WS that has this machine. Found a few and the charges ranges from $80 - $250.
Since it's the machine I am after and it has a database .... I took the WS that charged me the least - it's the machine doing the work and it's not about the mech's skills or experience.
View attachment 61152
Drove over to the WS and they hooked it up. Readings taken .......
View attachment 61147
It did not look that good ..... Even though it felt cold.
Then the mech started the engine and set it to max cold with windows open. This should get the freon etc going on the LP side ....... After 15 minutes - we proceeded to do the settings on the machine.
View attachment 61148
Selected the 3 series.
View attachment 61149
Configured the parameters ..... And kicked off the 4 processes
- recovery (empty out the freon and compressor oil)
- create vacuum to get rid of air and moisture
- refill freon
- refill compressor oil
View attachment 61150
Whole process takes about 45 minutes ........ Pics of how it progresses
View attachment 61151
View attachment 61153
View attachment 61154
View attachment 61155
After it was done - we decided to take the blower out and see its condition .....
View attachment 61156
The blower in my case is located right under the glove compartment.
View attachment 61157
After removing the cover, the blower is taken out ...
View attachment 61158
View attachment 61160
It looks terrible .....
View attachment 61159
Just scrapping it slightly and all that dust and grime that has been caked up breaks up ......
View attachment 61162
Blasted all that crap off ......and that should help improved the quality and intensity of the airflow.
Summary -
After all that is done - it seems to have helped reduce the cabin temp by about 2 Celsius. And the blower intensity improved especially for the side vents .......and I got what I wanted - using a device that is similar to BMW's approach to recharge my aircon.
P.s I am in no way related to that WS nor am I getting into the aircon business ........
Most of the articles I read are focused on the the low pressure and high pressure readings - I am still trying to correlate the relationship between BMW's weight approach versus pressure. See this - pic compliments from Daz3's ride and should be found under your bonnet if it hasn't been replaced like mine .....
View attachment 61144
Notice how it says 590 +- 10g as in BMW expects a variance of 10g for 590g of r134a refrigerant. And BMW also expects that in 2 years the variance would widen to 20g and at this point a recharge is needed.
So I set about figuring how do I add 20g of r134a back into the ride (assuming it lost 20g in the last 2 years). Most of the DIYs are about squirting the freon and stopping only when it hits a certain pressure. While it worked for some people I had feedback that it screwed a number of rides as well. Since BMW's approach is based on weight - I reckon that that approach is the correct approach and I decided not to recharge my aircon gas from a can of r134a.
There are 2 reasons -
- BMW did not do it that way
- A universal recharge by pressure approach by assume all car have an LP of x psi does not sound logical. How can all
cars be the same.
So I decided that I need to find the equivalence of the same aircon machine used by the BMW dealers to replace the freon and compressor oil. I started with Bosch since they are a major supplier of technology for BMW. And stumbled on to the AC 650. I decided to read the technical manual and found this -
View attachment 61145
View attachment 61146
The AC 650 apparently has a database of BMW vehicles and it is able to use this information to charge the r134a and the compressor oil with the right weight and viscosity.
So I decided to look for a WS that has this machine. Found a few and the charges ranges from $80 - $250.
Since it's the machine I am after and it has a database .... I took the WS that charged me the least - it's the machine doing the work and it's not about the mech's skills or experience.
View attachment 61152
Drove over to the WS and they hooked it up. Readings taken .......
View attachment 61147
It did not look that good ..... Even though it felt cold.
Then the mech started the engine and set it to max cold with windows open. This should get the freon etc going on the LP side ....... After 15 minutes - we proceeded to do the settings on the machine.
View attachment 61148
Selected the 3 series.
View attachment 61149
Configured the parameters ..... And kicked off the 4 processes
- recovery (empty out the freon and compressor oil)
- create vacuum to get rid of air and moisture
- refill freon
- refill compressor oil
View attachment 61150
Whole process takes about 45 minutes ........ Pics of how it progresses
View attachment 61151
View attachment 61153
View attachment 61154
View attachment 61155
After it was done - we decided to take the blower out and see its condition .....
View attachment 61156
The blower in my case is located right under the glove compartment.
View attachment 61157
After removing the cover, the blower is taken out ...
View attachment 61158
View attachment 61160
It looks terrible .....
View attachment 61159
Just scrapping it slightly and all that dust and grime that has been caked up breaks up ......
View attachment 61162
Blasted all that crap off ......and that should help improved the quality and intensity of the airflow.
Summary -
After all that is done - it seems to have helped reduce the cabin temp by about 2 Celsius. And the blower intensity improved especially for the side vents .......and I got what I wanted - using a device that is similar to BMW's approach to recharge my aircon.
P.s I am in no way related to that WS nor am I getting into the aircon business ........
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