Odd problem with my A/C

[A_A_G]

Need some help diagnosing what the problem might be. In the morning on my way to work I have no problem with it. It's about 80 degrees when I leave home and it blows cold.

On my way home, the temps are over 100, the belt squeals at times and the air goes from cold to almost hot to lukewarm and back.

Is it low on freon? Is the compressor going out? Would a loose belt cause this?

 

[brandini]

Nailed it.

Had the same problem recently and a full vacuum, leak test, and re-oil re-freon and I'm back to cold on even the hottest days.

 

[Errtt]

"belt squeals at times"
1st check belt condition and deflection (tightness), then go from there

 

[Samilcar]

Originally Posted By: A_A_G
Would a loose belt cause this?


Yes. If it's truly the belt that's squealing, that means the belt is slipping. If the belt is slipping, the compressor isn't turning (and compressing) as it should.

 

[jrustles]

Had this problem not long ago. Driving around the city, getting cold air, hit the highway, and it warms right up. 20 minutes later I smell burning belt. Since then, the skipping belt (and the shock loading from the moments of traction) took my compressor bearing out. Take care of that belt asap!

 

[Chris142]

Condenser fan working?

 

[Donald]

The belt needs to be replaced or tightened regardless. Then proceed with diagnosis. Temp probe in air duct. Manifold gauges on low & high.

 

[oldhp]

Serpentine belts are almost trouble free. What makes them act up 99% of the time is a bad tensioner assembly. A broken spring in the tensioner will act exactly as you describe.
Also check the idler pulley.