1998 Mercury Mystique air conditioning goes "cold-hot-

1998 MERCURY MYSTIQUE
150,000 MILES • 4 CYL • 2WD • AUTOMATIC
Avatar
BEN LEE
  • MEMBER
  • 66 POSTS
My AC will not consistently stay cold, but it is capable of getting cold, just completely inconsistent. Some days it will never get cold at all. Other days it will be cold for 15 minutes, then go warm and never go back to cold again on that same drive.

There have also been times that it will go back and forth continously throughout a 30 minute drive...stayin cold for 5 minutes, then going warm for 1 or 2 minutes, then back to cold...you get the idea.

The only thing I have done thus far is to charge the system, which did not seem to change anything, which may also mean that it didn't need charging.

Thanks for your input!
Nov 8, 2010 at 10:13 AM
Advertisement
Avatar
WRENCHTECH
  • ASE Certified Mechanic
  • 20,761 POSTS
  • ASE Certified Mechanic
Exactly how much refrigerant is in the system right now?
What are the high and low pressure readings at idle and at 2,000 RPMs?
Nov 8, 2010 at 10:31 AM
Avatar
BEN LEE
  • MEMBER
  • 66 POSTS
I'll have to get back to you on that. I don't have the gauage for measuring that.
Nov 8, 2010 at 10:37 AM
Avatar
WRENCHTECH
  • ASE Certified Mechanic
  • 20,761 POSTS
  • ASE Certified Mechanic
Then how could you have charged the system? That requires knowing exactly how much refrigerant the system has and what the pressures are. Otherwise, your just doing a whole lot of damage.
Nov 8, 2010 at 10:40 AM
Avatar
BEN LEE
  • MEMBER
  • 66 POSTS
Unfortunately I got some bad info and charged the system without knowing the pressure!
Nov 8, 2010 at 11:02 AM
Avatar
WRENCHTECH
  • ASE Certified Mechanic
  • 20,761 POSTS
  • ASE Certified Mechanic
Repairing an air conditioner requires a lot of knowledge and understanding of how the system works along with the proper equipment. It requires an exact amount of charge. This is really not a DIY type service because it has a high extreme potential for danger and damage to the system and I don't advise you to mess with it yourself.

I'm going to back out of this and let someone else take over.
Nov 8, 2010 at 11:09 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.