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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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 Posted: Mon Jan 15, 2018 1:50 am Post subject: car ac problems... |
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Hey all! Ive been trying to diagnose why my honduhs ac hasnt been as cold as i remember. actually it seems to be colder but in the wrong place...
I noticed that the compressor is cooler to the touch relative to the engine bay and its pulley, shouldnt the compressor be quite warm as compressing the refrigerant raises temp? the low side pressure is at 60 psi idle. ambient temp right now is 32 celsius, and the vent temp is only 29C. i have no idea what the high side pressure is...
much help appreciated, thanks in advance!
Edit: actually the compressor isnt cooler to the touch, its cold!
Last edited by bug1200 on Mon Jan 15, 2018 3:12 am; edited 1 time in total |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Mon Jan 15, 2018 2:01 am Post subject: Re: car ac problems... |
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| i forgot to mention that the suction line is sweating excessively near the compressor.. actually, the whole compressor is sweating. but closer to the evaporator, sweat is minimal... |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Mon Jan 15, 2018 8:37 am Post subject: Re: car ac problems... |
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R-12 or R134a?
You really need to measure both low side and high side pressures at about 2000 rpm with the compressor engaged, not at idle.
Only by removing refrigerant and having it weighed can a true assessment of charge level be made.
Are there electric fans over the CONDENSERS, and are the working?
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Mon Jan 15, 2018 10:04 am Post subject: Re: car ac problems... |
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| Cusser wrote: |
R-12 or R134a?
You really need to measure both low side and high side pressures at about 2000 rpm with the compressor engaged, not at idle.
Only by removing refrigerant and having it weighed can a true assessment of charge level be made.
Are there electric fans over the CONDENSERS, and are the working? |
R134a
the high side gauge doesnt want to give any readings on the honda... refrigerant came out when i pushed on the valve, and the gauges worked on my nissan. perhaps its the design of the schrader (spelling?) valve?
the cooling fans are behind the radiator, they are working.
FWIW, cooling reduces even more if the condenser is splashed with water. |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Mon Jan 15, 2018 11:05 am Post subject: Re: car ac problems... |
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| bug1200 wrote: |
R134a
the high side gauge doesnt want to give any readings on the honda... refrigerant came out when i pushed on the valve, and the gauges worked on my nissan. perhaps its the design of the schrader (spelling?) valve? |
What year is the Honda?
Was it factory R134a or converted to R134a? Maybe someone converted and only put an adapter valve on the low side; maybe you could post a good picture of your high side valve.
Need high side pressure like I said before.
| bug1200 wrote: |
the cooling fans are behind the radiator, they are working.
FWIW, cooling reduces even more if the condenser is splashed with water. |
Yes, because you are cooling the condenser more. Driving produces more air flow than idling too.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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skills@eurocarsplus
Samba Peckerhead
Joined: January 01, 2007
Posts: 16849
Location: sticksville, ct.
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| Posted: Mon Jan 15, 2018 6:52 pm Post subject: Re: car ac problems... |
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your pressures swing with ambient temp
80* day high should be 170/200 and low should be 40/50
low high side could be a bad compressor (amongst other things)
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Mon Jan 15, 2018 8:31 pm Post subject: Re: car ac problems... |
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@Cusser, its a 96 civic. came with r134a factory.
I had my friend check with his gauges. Low side is at 60 psi, high side 350psi. since skills said that the low should be 50 and high 200, what do my pressures indicate? my friend is suggesting an overcharge. but i havent had my ac touched, ever.
EDIT: although my friend also stated that pressures could also be very high even in an undercharged condition... im confused now. |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Tue Jan 16, 2018 7:27 am Post subject: Re: car ac problems... |
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| bug1200 wrote: |
@Cusser, its a 96 civic. came with r134a factory.
I had my friend check with his gauges. Low side is at 60 psi, high side 350psi. since skills said that the low should be 50 and high 200, what do my pressures indicate? my friend is suggesting an overcharge. but i havent had my ac touched, ever.
EDIT: although my friend also stated that pressures could also be very high even in an undercharged condition... im confused now. |
Your readings are high for both low and high side. That typically means:
...too much refrigerant in system
...air in the system
...condenser not cooling the hot gaseous refrigerant to hot liquid refrigerant as it should. One typically sprays water on the condenser when getting such high readings, to see if pressures immediately drop (which they should).
Make sure that air flow through condenser is perfect, that all fan shrouds are in place, all electric fans for radiator/condenser on full speed.
But I think next step is to have a professional extract and weigh the R134. Most shops in USA do NOT have an upcharge to add back your own R134a.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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Zeen
Samba Member
Joined: July 24, 2004
Posts: 1308
Location: The Sunny Part of Michigan
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| Posted: Tue Jan 16, 2018 1:08 pm Post subject: Re: car ac problems... |
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| Cusser wrote: |
| bug1200 wrote: |
@Cusser, its a 96 civic. came with r134a factory.
I had my friend check with his gauges. Low side is at 60 psi, high side 350psi. since skills said that the low should be 50 and high 200, what do my pressures indicate? my friend is suggesting an overcharge. but i havent had my ac touched, ever.
EDIT: although my friend also stated that pressures could also be very high even in an undercharged condition... im confused now. |
Your readings are high for both low and high side. That typically means:
...too much refrigerant in system
...air in the system
...condenser not cooling the hot gaseous refrigerant to hot liquid refrigerant as it should. One typically sprays water on the condenser when getting such high readings, to see if pressures immediately drop (which they should).
Make sure that air flow through condenser is perfect, that all fan shrouds are in place, all electric fans for radiator/condenser on full speed.
But I think next step is to have a professional extract and weigh the R134. Most shops in USA do NOT have an upcharge to add back your own R134a. |
It can't be an overcharge if nobody has added anything. I don't see how you can get air in; any leak would have to let most of the refrigerant out before it could let any air in.
Since the high side is very high, and the low side is only slightly high, my vote is a clogged orifice tube.
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The consequences of your decisions should not be confused with fate. |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Wed Jan 17, 2018 12:58 am Post subject: Re: car ac problems... |
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well actually the honda uses a txv, not an orifice tube...
i ended up replacing the reciever dryer and txv. i also flushed the system and replaced compressor oil just to be sure.
the gauge readings are now 45 psi low, 225 psi high. i did not weigh the refrigerant as the damn scale isnt working... lowers a bit when revved. although the compressor doesnt cycle as frequently anymore, i assume its a good thing?
also FWIW, just to share some methods we locals here use to evacuate the system (recovery machines here would cost 2 of my hondas lol!):
you can dip an empty tank of refrigerant in ice cold water, connect the gauges then open the valves. almost all of the refrigerant would go to the empty tank! any amount left would be negligible.
did you also know that with the proper mods, you can turn the compressor of your fridge into a vacuum pump? an effective one too.
the outlet of most vacuum pumps arent meant to be pressurized, but a compressor is... with the proper fittings you can connect the suction of your fridge compressor to the low side port of the car and your refrigerant tank to the liquid line of the fridge comp. cheap recovery machine!
although most people here would just vent to the atmosphere... |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Wed Jan 17, 2018 8:43 am Post subject: Re: car ac problems... |
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| bug1200 wrote: |
also FWIW, just to share some methods we locals here use to evacuate the system (recovery machines here would cost 2 of my hondas lol!):
you can dip an empty tank of refrigerant in ice cold water, connect the gauges then open the valves. almost all of the refrigerant would go to the empty tank! any amount left would be negligible. |
I pull a vacuum on an empty 2-lb refrigerant canister, place that in a cold bath of dried ice (from grocery store) and old engine coolant, and then let the vacuum pull refrigerant over. The refrigerant condenses into a liquid, so vacuum still there, and more refrigerant gets pulled over.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Thu Jan 18, 2018 12:58 am Post subject: Re: car ac problems... |
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UPDATE: coolings gone again, low side is at 60 psi, high side is at 190.
for some reason low side goes down and high side goes up a bit when engine is revved... strangest situation... |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Thu Jan 18, 2018 8:19 am Post subject: Re: car ac problems... |
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| bug1200 wrote: |
| for some reason low side goes down and high side goes up a bit when engine is revved... strangest situation... |
That is typical.
| bug1200 wrote: |
| UPDATE: coolings gone again, low side is at 60 psi, high side is at 190. |
Do you mean that it cooled OK after evacuation and refilling with proper amount of R134a, and now later it is not? That sounds like a leak.
Are those pressure readings all at about 2000 rpm?
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Thu Jan 18, 2018 7:47 pm Post subject: Re: car ac problems... |
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it cooled much better after the evac and recharge. it doesnt get as cold now but still better than when i first started.
the pressure readings were at idle, changes only slightly when engine is revved.
i recovered the r134a again with my fridge compressor, pumping it to a small empty tank of refrigerant after placing it to my digital scale and zeroing it out. it measured at about .51 kilos.
i then switched to my real vacuum pump, vacuumed to about 27 inches... been keeping this vacuum for about 2 hours now (pump off of course) and theres still 27 inches... |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31352
Location: Hot Arizona
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| Posted: Fri Jan 19, 2018 7:24 am Post subject: Re: car ac problems... |
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| bug1200 wrote: |
| it cooled much better after the evac and recharge. it doesnt get as cold now |
Sounds like a leak.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22396
Location: Kimball, Mi
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| Posted: Fri Jan 19, 2018 12:42 pm Post subject: Re: car ac problems... |
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| bug1200 wrote: |
UPDATE: coolings gone again, low side is at 60 psi, high side is at 190.
for some reason low side goes down and high side goes up a bit when engine is revved... strangest situation... |
Pressures can change with use.
I'm betting you have a dampener door not moving all the way. That's also a common problem on Hondas (the dampener door hanging up, or the motor powering it taking a dump).
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71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
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skills@eurocarsplus
Samba Peckerhead
Joined: January 01, 2007
Posts: 16849
Location: sticksville, ct.
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| Posted: Fri Jan 19, 2018 12:51 pm Post subject: Re: car ac problems... |
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| bug1200 wrote: |
i then switched to my real vacuum pump, vacuumed to about 27 inches... been keeping this vacuum for about 2 hours now (pump off of course) and theres still 27 inches... |
don't get burnt by thinking just because it's holding a vacuum all is well. pulling vacuum isn't going to show a leak (usually) unless it's huge.
when under vacuum, it could seal up a leak. remember this is a pressurized system. I would recharge and dye the system. I would also use my refrigerant leak sniffer as well, but the dye works real well too.
_________________
| gprudenciop wrote: |
my reason for switching to subaru is my german car was turning chinese so i said fuck it and went japanese....... |
| Jake Raby wrote: |
| Thanks for the correction. I used to be a nice guy, then I ruined it by exposing myself to the public. |
| Brian wrote: |
| Also the fact that people are agreeing with Skills, it's a turn of events for samba history |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Sat Jan 27, 2018 8:38 am Post subject: Re: car ac problems... |
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UPDATE: after repeated evacuating and recharging of the system weighing each evac and charge (consistent results btw), i have come to the conclusion that the compressors broke.
In short: compressor replaced, everything good (for those who dont wanna read my blabbering)
after connecting the gauges to a same model honda with a known good condition ac, i recorded the low side at 45psi and the high side at ~220ish psi at 1500rpms. the compressor shuts off at about 30psi low, turns on at 60psi high.
tried charging my civic till the high pressure is at 220psi, sight glass was clear like the system isnt running and cooling was non existent (suggesting an overcharge).
since the charge by weight that resulted in 60psi low, 190psi high is the correct charge; and a properly charged system should result in approx. 45 low, 220 high; the only conclusion would have been the compressor not having the correct compression ratio (broken).
a replacement was a last resort for me as there are alot of fakes here in my place, sometimes even marked with honda in the box etc. etc. and its expensive too. so i tried to add a wee bit more oil to the compressor (low oil could cause low compression) to no avail.
after finaly deciding to replace the compressor; i took apart the whole system, flushed it, cleaned the evaporator/condenser fins, replaced txv and dryer again, plus all the o rings.
i then put the correct amount of oil in the compressor (some of it in the reciever dryer), vacuumed 15 mins, left off for 30 mins... vacuum stayed the same blah blah so vacuumed for another 45 mins or so, then charged the system.
now for the moment of truth! unfortunately cooling was still subpar! until i revved the engine for a few minutes though! the pressures are now 50 psi low and 250 psi high on a 31 degree celsius day. although pressures are different from the other civic cooling is actually better. probably due to the new compressor
thanks guys for your help, i hope this would help anyone who would have a similar problem with their ac. |
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bug1200
Samba Member
Joined: July 07, 2015
Posts: 222
Location: Philippines
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| Posted: Sat Jan 27, 2018 8:49 am Post subject: Re: car ac problems... |
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the ac is now blowing ice cold, even colder than my nissan, and my '11 hyundai.
although the hyundai would blow colder air in the passenger side and warmer air in the driver side, but i digress
only question is why my compressor broke in the first place, the ac has never been touched; although relatives have been using it for some time now. my toyotas ac never had a problem aside from gradually running out of refrigerant due to age.
now its time to work on my bugs ac, which has a problem of not having one at all! jk |
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