SaturnFans.com
what's new (beta) - classifieds - forums - photos


Go Back   SaturnFans.com Forums > Models > Saturn S-Series > S-Series Tech
Register FAQ Members List Groups Calendar Chat Room Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
Old 09-28-2006, 03:42 PM   #1
d4rkf1ber
Junior Member
d4rkf1ber is on a distinguished road
 
Join Date: Sep 2006
Posts: 21
Question A/C Problems - '99 SL2

Need help troubleshooting A/C problems on a '99 SL2. I am NOT planning on doing the work myself, however I like to try to get a good handle on things before I ask others to do it for me, mainly for personal growth/knowledge and to not be suckered into unneeded things like many pro's try to do to you.

Ok, so the problem is that A/C is not getting or staying cool while car is not moving. Just started yesterday. While car is moving A/C feels fine.

Today I popped the hood and looked and listend. I noticed that the belt to the A/C compressor is tight and turning fine. I hear a noise though sounds like the fan over the radiator is making a noice, kinda sounds like plastic touching plastic when it is spinning, not bad just noticeable but obviously not right. Anyway, that was about it. So I just watched and listened for a while as the car ran in park under the carport.

Then I start noticing the compressor turning off which seems to coincide with the fan over the radiator turning off. The belt portion of the compressor always spins of course since its tied to the serpentine belt. I am unfamiliar with cars and how things work so forgive me here. As I am watching I noticed that there is a part of the compressor that spins but can also stop spinning, did not realize this until I saw it slow down and stop. Just thought it spun originally because its right there where the serpentine belt is.

Anyway, when this thing slows down and stops, the fan over the radiator does as well. Not sure how or why they are tied together but they are.

It happend rather frequently as I watched it. I know if a compressor is bad or going bad it will obviously affect the A/C cooling. But since a compressor is a tad expensive, I want to make sure nothing else could be affecting it or its performance. Also curious what controls when it is engaged or not? Since it works fine while driving there is a part of me that thinks the compressor might be ok, otherwise the A/C would not cool no matter what.

Who knows, seeking any advice or input before I head over to a pro.

Thanks!

REWARD EXCELLENCE!

Add to d4rkf1ber's Reputation
Rate the quality of this post and help d4rkf1ber reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
d4rkf1ber is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 09-28-2006, 03:56 PM   #2
BarnOwl
Super Member
BarnOwl is just really niceBarnOwl is just really niceBarnOwl is just really niceBarnOwl is just really nice
 
BarnOwl's Avatar
 
Join Date: May 2005
Location: Hickory, NC
Posts: 10,029
 

2000 SW2
1998 SL2
Default Re: A/C Problems - '99 SL2

You're freon is probably just a little low. So, you probably have a small leak somewhere. Most shops will probably put some UV dyed freon in there and tell you to come back when it stops cooling again and they'll be able to find the leak.

The fan and A/C are associated. The fan will come on whenever the A/C compressor is running to pull air through the A/C condenser. Thus providing you with cooler air.

...
There is nothing more frightening than ignorance in action.

REWARD EXCELLENCE!

Add to BarnOwl's Reputation
Rate the quality of this post and help BarnOwl reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
BarnOwl is offline   Reply With Quote
Old 09-28-2006, 04:25 PM   #3
d4rkf1ber
Junior Member
d4rkf1ber is on a distinguished road
 
Join Date: Sep 2006
Posts: 21
Default Re: A/C Problems - '99 SL2

Low freon would be great if thats all it is. Wonder why or how low freon seems to cause such an affect only while the car is not moving? Moving and it feels fine. Without knowing how any of this works I just would have guessed that low freon would cause the same lack of cooler air even while moving?

Also, any insight into what controls whether the compressor is on or not? Again just guessing here but if the compressor coming on means the cooling process begins, which in some way it does since without it being on means your not going to get cool air, I would guess it is controlled via a thermostat maybe? So if it is controlled via a thermostat, and the car is obviously not getting cold and air coming out the vents is not cold, then why would the compressor be going on and off so much? I would think it would not turn off until the thermostat had a reading in which indicated it was ok to turn off now?

Again I dont know anything about this stuff, only using common sense or at least my version of common sense to try to figure things out, and that is not always a good thing. :-)

Thanks for the response!

REWARD EXCELLENCE!

Add to d4rkf1ber's Reputation
Rate the quality of this post and help d4rkf1ber reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
d4rkf1ber is offline   Reply With Quote
Old 09-28-2006, 04:53 PM   #4
BarnOwl
Super Member
BarnOwl is just really niceBarnOwl is just really niceBarnOwl is just really niceBarnOwl is just really nice
 
BarnOwl's Avatar
 
Join Date: May 2005
Location: Hickory, NC
Posts: 10,029
 

2000 SW2
1998 SL2
Default Re: A/C Problems - '99 SL2

The compressor going off and on is being controlled by a pressure switch that is there to protect your compressor. Too little freon will hurt the compressor, so will too much. The pressure switch will stop the compressor from running when there is either too much pressure or not enough. I never said that all you need is freon. If your freon is low, it got out somehow and that leak needs to be fixed. However, many times a freon leak is very slow and can't easily be found. So, they put a UV dye in and when it leaks out, it'll leave a visual indication of where the leak is.

...
There is nothing more frightening than ignorance in action.

REWARD EXCELLENCE!

Add to BarnOwl's Reputation
Rate the quality of this post and help BarnOwl reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
BarnOwl is offline   Reply With Quote
Old 09-28-2006, 06:40 PM   #5
d4rkf1ber
Junior Member
d4rkf1ber is on a distinguished road
 
Join Date: Sep 2006
Posts: 21
Default Re: A/C Problems - '99 SL2

Well after further testing and driving it appears to be the fan over the radiator portion of the car. I sat in the driveway with the car running in drive, and the parking brake on. After a while not only was the A/C not staying cool but the engine temperature started going up. The engine temperature needle never goes to the mid way point, even on the hotest day here in south louisiana and this time it went past the middle point.

I immediately got out of the car and checked under the hood. The fan is turning, but that noise I mentioned earlier is worst and the fan is wobbly and does not seem to be moving as it really should.

I know enough to know that cars run cooler while actually moving due to the air flow then when they sit still and then you depend on the fan to do the work. So it makes sense from an engine perspective that things were cooler while driving and not so when stuck in traffic, however I guess I am not getting the association between that fan and the A/C despite the obvious fact they are tied together.

Guess I am going see how much it costs to replace that fan, it kinda looks do able on my own, but getting access to a couple of things does not look easy at all.

REWARD EXCELLENCE!

Add to d4rkf1ber's Reputation
Rate the quality of this post and help d4rkf1ber reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
d4rkf1ber is offline   Reply With Quote
Old 09-28-2006, 08:13 PM   #6
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 41,479
 

2003 L-Series 3.0L Sedan
Default Re: A/C Problems - '99 SL2

The a/c will extract heat from the interior of the car and send it to the condenser coil, in front of the radiator, adding to the heat from the radiator. The radiator fan must be on to either pull air through both condenser and radiator coils or blow through them both to keep a constant airflow. Normally when the a/c is on the radiator fan stays on regardless of whether you adjust for cold, medium, or hot air. The dual heat loads coming from the a/c and radiator leaves the fan on. When the a/c is off there is only the radiator to cool off and then only when water temperatures are at, say 200 degrees F., the fan turns on to cool the radiator until a lower temperature is reached whereupon the fan is switched off automatically. In this situation the fan is controlled by the ECM whose input is the engine coolant temperature sensor. The automatic fan control circuit.

The a/c running creates an extra heat load where the ECM bypasses the normal automatic radiator cooling circuit and leaves the fan on. There isn't any thermostatic control for the a/c to turn off for temperature control as you may have suspected but something else is turning off the a/c. That something else was pointed out in the previous post related to a possible refrigerant leak that created an abnormal condition-the cycling of the compressor running and then not running that you observed under the hood. Normal air conditioning will have the compressor running constantly. For a person that doesn't know much about air conditioning you certainly are observant enough to carefully describe your situation clearly. What appears to be the a/c running one moment and then not running is due to the possible lower pressure of the refrigerant that a pressure switch detects as too low to allow the a/c to continue thereby turning off the a/c and turning it back on as if there were a thermostat controlling the a/c. Not so as this isn't a normal situation but you were concerned enough to notice a less than normal cooling of the a/c system to look under the hood. You just happened upon the beginnings of a failing a/c system most would not have noticed until much later when a total absence of cooling has taken place. As an aside, some vehicles do/did have a thermostatic temperature control that indeed turns off the compressor just as you described but for one reason or another this fell out of favor. I believe our Saturns don't have this feature in favor of leaving the compressor running full time while improvements in the design of modern compressors requires less power to run continuously. To this end the blend door (in the center dash console) and the heater coil through either a lever or electronic temperature control adjusts for the amount of cold/hot air or anything in-between. The electronic temperature control is what I have in my L300 and called Auto-Temperature Control when I leave it on or revert to manual mode to leave the a/c off. Leaving it on only controls the blend door to mix the hot air from the heater coil and the cold air from the evaporator coil. It won't turn off the a/c, as in turning off the compressor.

Replacing the fan may help but that is a separate issue since you state that the fan is making a rubbing sound and doesn't appear to run correctly. Most everyone here will tell you that since the fan runs when commanded to without the a/c on and runs the instant you switch on the a/c the fan is working correctly. The replacement may be warranted due to the age of your car. If after you have the fan replaced and you still have an a/c problem take the car to a known good a/c shop for diagnosis. And for more info go to http://ackits.com to learn about car a/c. You can also read A/C Basics in the miscellaneous tech section.

REWARD EXCELLENCE!

Add to fdryer's Reputation
Rate the quality of this post and help fdryer reputation points. Click the reputation button near the bottom left corner of this message box. Thank you!
fdryer is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Problems with 97 SL2 jonnycube S-Series General 35 05-07-2009 11:16 AM
engine swap from a 93 sl2 to a 95 sl2 problems caspergsx S-Series Tech 23 01-01-2008 01:36 PM
98 sl2 problems datstrukid S-Series Tech 6 11-04-2007 08:27 PM
'96 SL2 with Problems> HELP ME PLEASE!! angel S-Series Tech 6 08-15-2004 02:17 PM
Problems with a SL2 Mjollnir S-Series Tech 5 12-01-2000 07:09 AM


All times are GMT -4. The time now is 01:30 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
SaturnFans.com. The Saturn Enthusiasts Site.