Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Arnott
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-29-2021, 12:10 AM
Member
 
Join Date: Aug 2018
Location: Central FL
Posts: 100
Mike1261 is on a distinguished road
A/C charged, then overcharged, but still low pressure

I just replaced the AC compressor in my E53.

Prior to replacing it, it would take 10-20 minutes for it to start blowing cold.

Ambient temperature is 80F so everything suggests I want to see 40-50psi on the low port.

It took 20 minutes to get a 12oz can into the system.

I then switched to the second can and was watching the pressure gauge to determine when the system was full.

15 minutes later the second can was empty and the gauge was still reading about 38psi.

The spec calls for just shy of 16oz in the system. I now have just shy of 24oz in the system. AC blows pretty cold but I'm concerned that it's overfilled and that the pressure still appears low.

I did also replace the dessicant in the drier fwiw.

Not sure where to go from here. Even if I evacuate the system and start over, how on Earth do I know I'm at 440 grams if I can't look at the pressure reading. I suppose I could keep unhooking the canister and weighing it but that seems a bit annoying, and I'd lose some freon every time I purge the line too so would throw off the result there as well.

Thoughts?
__________________
2006 BMW X5, 3.0i - 133,000 miles
2003 Ford Mustang GT - because having Two cars that keep dying seemed more exciting.
Reply With Quote

Sponsored Links

  #2  
Old 07-29-2021, 08:01 AM
Member
 
Join Date: Mar 2016
Location: Saskatchewan Canada
Posts: 1,242
80stech is on a distinguished road
You can't tell the amount of charge by reading the low side pressure. If you are not using the proper refrigerant the pressures will be different. Charge by weight only with proper refrigerant into an evacuated system that is clean and has the proper amount of oil or take it to a competent A/C shop, tell them what was done and let them finish it.
__________________
1988 325is (purchased new)
2004 X5 3.0 (new to me) 2005 X3 2.5 (new to wife)
Reply With Quote
  #3  
Old 07-29-2021, 09:00 AM
andrewwynn's Avatar
Member
 
Join Date: Jun 2015
Location: Racine, WI
Posts: 8,184
andrewwynn will become famous soon enough
You need to read high and low side pressure. If you have non variable compressor you should see numbers like 45/240 @ 90F I'm not sure what that drops down to at cooler temps I always find myself working on AC on the hottest days.
__________________
E53 / M54 2001 3.0i gas LHD (pair of them: his & her)
Reply With Quote
  #4  
Old 07-29-2021, 12:20 PM
Member
 
Join Date: Jan 2013
Location: TX
Posts: 74
txyaloo is on a distinguished road
Quote:
Originally Posted by Mike1261 View Post
I just replaced the AC compressor in my E53.

Prior to replacing it, it would take 10-20 minutes for it to start blowing cold.

Ambient temperature is 80F so everything suggests I want to see 40-50psi on the low port.

It took 20 minutes to get a 12oz can into the system.

I then switched to the second can and was watching the pressure gauge to determine when the system was full.

15 minutes later the second can was empty and the gauge was still reading about 38psi.

The spec calls for just shy of 16oz in the system. I now have just shy of 24oz in the system. AC blows pretty cold but I'm concerned that it's overfilled and that the pressure still appears low.

I did also replace the dessicant in the drier fwiw.

Not sure where to go from here. Even if I evacuate the system and start over, how on Earth do I know I'm at 440 grams if I can't look at the pressure reading. I suppose I could keep unhooking the canister and weighing it but that seems a bit annoying, and I'd lose some freon every time I purge the line too so would throw off the result there as well.

Thoughts?
You need a scale or a machine like this to ensure you're loading the right amount of refrigerant. Even on a low side fill, it shouldn't take 20 minutes to do a low side fill if you have a strong vacuum in the system. How long did you vacuum and did you let it sit to ensure you don't have any leaks before adding refrigerant?

This AC machine was the best $250 I've ever spent on FB Marketplace.
Reply With Quote
  #5  
Old 07-29-2021, 01:38 PM
Member
 
Join Date: Aug 2018
Location: Central FL
Posts: 100
Mike1261 is on a distinguished road
Vacuum was 27-28" on Low side. 30" on high side. What does the difference in vacuum mean?

Pump isn't stellar. It's a cheap air compressor run pump. Not electric.

Let sit 45 mins. No leaks.

Low side was reading 38psi at 80F but high side was up at 270 by the time the second can emptied in, which is over filled.

I had a friend evac the system for me this AM. Will refill to 440g per spec and see where we are at.

I feel like the expansion valve may be suboptimal. That's what some troubleshooting sites seem to indicate and might also explain why it struggles to truly keep up on a 90 degree day. Cool yes. Ice cold. No.

But the biggest issue was the compressor taking 10-15 minutes to start working (and after sitting 9 months, it didn't cool at all anymore lol). That has been solved now in time for our drive up to Canada next week.

If the expansion valve needs replacing, I suspect that's a big job and I don't have time for it so hopefully it holds out for another year.
__________________
2006 BMW X5, 3.0i - 133,000 miles
2003 Ford Mustang GT - because having Two cars that keep dying seemed more exciting.
Reply With Quote
  #6  
Old 07-29-2021, 08:00 PM
Member
 
Join Date: Jun 2021
Location: Austin, TX
Posts: 223
X5chemist is on a distinguished road
Did the auxiliary fan turn on at any point? Is your mechanical fan up to par? Is your upper center dial all the way to three blue dots? Which fan setting did you use? Max? Auto? Manual fan speed?
__________________
'06 X5 3.0i - bought @143,123 miles (12/26/20)
Reply With Quote
  #7  
Old 07-31-2021, 12:32 PM
Member
 
Join Date: Aug 2018
Location: Central FL
Posts: 100
Mike1261 is on a distinguished road
Issues all resolved!

The can tap was not working properly and wasn't letting coolant escape from the recharge cans at an appropriate pace.

I found my old can tap from 2001 and it worked great.

All the pressures are now in line with spec mid 40's and around 210 at 80F.

AC blows cold.

I weighed the cans while recharging (making sure to bleed air on each reconnection) until the system was at the 440g spec.

Aux fan is new. Mechanical fan clutch is new. As are waterpump and thermostat and hoses and catch can. Aux fan doesn't like coming on when I'm parked and AC set to Auto. The warm humid air it spits out are annoying so I take it off auto and he aux fan kicks in again. Is this normal?

Looks like everything is good to go just in time to drive up to Canada next week and endure that ridiculous 14 day quarantine and 3 Covid tests.
__________________
2006 BMW X5, 3.0i - 133,000 miles
2003 Ford Mustang GT - because having Two cars that keep dying seemed more exciting.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 03:44 PM.
vBulletin, Copyright 2021, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.