1992 240 air conditioner

The ac blows cold while car is at idle but the faster the engine turns less cold air is being produced. I have no leaks and correct amount of R134, ANY SUGGESTIONS.

Reply to
Rick Shockley
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Is there less air or just less cold? Is the belt properly adjusted?

Reply to
James Sweet

Sounds like you're losing the engine vacuum that holds the vents open (Volvo used vacuum solenoids to open/close the floor, windshield and recirculation vents in the 240s). Replace the check valve on the intake (it's the one that sticks up from the intake runner #4, the one closest to the firewall). It might also be the vacuum bottle that it connects to leaking or a hose being off or cracked on the interior ventilation system, but those would also cause a rough/searching idle. I've never had to replace an interior component but have replaced the check valve in many 240s. Bill

Reply to
Bill Bradley

At the risk of sounding like a broken record, this sounds like a job for a pro. I fear the compressor valves are failing, but R134a is spooky enough that it could also be a symptom of slightly low charge. If it has been evacuated and filled by weight you have the correct charge as you say, otherwise probably not. A tech can also tell you by the pressure behavior if the valves are leaky.

Or, as Bill says, it could also be vacuum problems. From my experience with the vacuum problems in my '85 765T, if it is vacuum you should feel the air getting cold within a couple seconds of letting off the throttle from highway speeds. Charge problems shouldn't respond that quickly.

One more thing - a long shot but quick and cheap - try spraying the condensor with a spray attachment on a garden hose. Dirt in there can do weird things and it never hurts to make sure it's clean. (Been humbled by that myself.)

Mike

Reply to
Michael Pardee

Reply to
Rick Shockley

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