The Lotus Cars Community banner

1 - 6 of 6 Posts

·
Registered
Joined
·
174 Posts
Discussion Starter #1
I just finished a replacement of my condenser with a unit from ProAlloy. AC vacuum and charge went as expected. AC turns on and Compressor works. Pressures are OK. 45 Low and 175 high. Here's the odd thing. The high pressure side is crazy hot. Like 150 degrees into the condenser. It drops to 115 on the exit from the condenser. Needless to say the AC isn't working great. Vent temp is 61 with 85 degree ambient. What am I missing. That high pressure line seems crazy hot? Like scald you if you touch it hot. What gives? Maybe its normal? The AC system never was great but it seems particularly weak now.

Thanks in advance for any advice.
 

·
Registered
Joined
·
4 Posts
Yes, that is normal. It automotive a/c systems, you will find that the temperature roughly equals the pressure. It drops after the condenser because the condenser is cooling the high pressure gas into a slightly less high pressure liquid. 175 on the high side seems a little low, I usually see @ 250 high side and 30-40 on the low on most cars. Sounds like it might need a little more refrigerant. How much did you charge it with? My Elise was happiest with about 1.5-1.6 lbs.
 

·
Registered
Joined
·
174 Posts
Discussion Starter #3
Yeah, I have less. About 1.2 lbs. the chart I had said 175 was the high for my ambient of 80. Plus my low was starting to hit 45. I guess I could push more and see what happens. The cooling is weaker than I recall. I was freaked out by how damn hot the high pressure side was.
 

·
Premium Member
Joined
·
2,738 Posts
Not to be an AC weenie, but you should charge the system by weight. Actually not hard to do with regular cans and estimating.

The high side is going to be screaming hot, that is the point.


Are the fans on?

Is the output temp at idle?

AC is pretty paltry at idle.
 

·
Registered
Joined
·
174 Posts
Discussion Starter #5
Good to know the high side is supposed to be screaming hot. I went ahead and pushed the pressure a little higher. That did result in some imporovement. I think my main issue was heat soak of the condenser as the car sat there idling. I got so busy fussing with pressure gauges the car got pretty hot last time and I think that inserted a changing variable. With this more recent gas tweak, the car wasn't idling for as long. I think that was the problem. The condenser just cannot release sufficient heat while the car sits still. During the test drive I was seeing vent temps in the high forties. Probably 48 on average. Pretty good. I may have finally gotten this AC problem licked! Thanks for everyone's help!
 

·
Premium Member
Joined
·
2,738 Posts
The AC is weak at idle no matter what.

After my tune with a slightly higher idle, and fans that come on high at a lower temp, AC performance seems improved
 
1 - 6 of 6 Posts
Top