A/C Blows Hot Briefly

[gtyates]

I had an odd experience today. 97 Explorer OHV. The A/C was working great, then I had to accellerate quickly to pass someone. While I was accellerating, the A/C starting blowing hot, and I could smell something like a slipping/hot belt. Turned off the A/C system, and drove it on home. Dropped off the family, then took it back out, and the A/C is working great again, even under load. I cannot duplicate the problem so far. Has anyone else experienced anything like this? Does the compressor turn itself off under load for protection? The only A/C issue I have had is the famous accumulator rysing out, but thas about 5 years ago. Truck has 113k on it, and manual a/c controls.

 

[aldive]

Were you at WOT? If so, that explains it; the compressor shuts off at WOT.

 

[shamaal]

There is a Wide Open Throttle (WOT) that disengages the A/C clutch when the throtlle is .... wide open.

Another possibility is that the vacuum reservoir is full of water from condensation. The vacuum reservoir 'stores' vacuum so that when the throttle is opened and the vaccum supply drops, the vacuum affected controls like recirc aren't affected.

No explanation for the smell.

 

[Jason94sport]

I would say the WOT thing as well. It's common. The smell was from the air in the vents when the AC shut off. Common as well. If it's seems fine now I wouldn't worry about it.

 

[aldive]

You might want to spray some Lysol through the vents. I do this to mine about 3 times a year; removes the musty smell.

Good luck ....

 

[gtyates]

Thanks for the tips so far. I thought there might be an automatic shut-off feature in a wide open throttle situation. I wonder if the smell was maybe where when the compressor shut off it briefly "froze up" its pully and caused the belt to rub and make a smell? The smell was definitely a burning rubber type of smell, like a belt. I drove the truck again this morning, and everything is functioning great, and no smell. Very odd thing indeed!!

 

[BrooklynBay]

How old is the belt? Did you see if it looks like it has small cracks?

 

[gtyates]

I honestly do not know how old it is. Every time I have it serviced, I have the shop check the belt, and they have not indicated a need to replace it. I have owned the truck 5 years, and have put about 80k on it since I bought it. truck has 113k now.

 

[BrooklynBay]

It might be a good time to check, and possibly replace the belt.

 

[gtyates]

Well, I spoke too soon. I was out running errands this afternoon and the a/c again starting blowing warm. I immediately turned the system off, then got off the highway. After coming to a stop, I attempted to turn the a/c system back on, and heard a loud noise. is my compressor maybe dead? Up until this happened today, it was blowing good and cold.

 

[BrooklynBay]

You should connect a manifold gauge set to check the high, and low pressure.

 

[gtyates]

I can follow-up further. When I attempt to engage the a/c, I can see and here that either the clutch or the compressor is the issue. I had someone inside the truck hit the a/c swith, and at that instant I can hear a loud sound like something is seized up, and I can actually see what looks like shavings flying at the compressor/clutch assembly. As long as the a/c is off, the truck runs fine, no belt issues, etcc., only an issue when engaging the a/c. So, in my humble novice opinion, I think it is either the compressor or the clutch. Since the system was working perfectly up until the time it blew hot, could it simply be the clutch?

 

[gtyates]

Further follow-up. The compressor was seized. After a complete system rebuild, all is ice cold again.