Hi, I just recharged the A/C on my 98 Civic DX and thought everything was fine as it cooled off nicely. It worked fine for about 15 minutes and then started blowing warm air. The same thing happend on my way home today. Nice and cold for 15 minutes and then no cold air. Any ideas as to how I can solve this problem? It's getting warm down here in Texas.

Thanks!

 

When the air blows hot, does the condenser fan stop running or does the compressor clutch disengage?

Did you measure the refrigerant pressures on the low and high sides when you recharged the system?

 

As it gets cold sometimes, it has enough refrigerant. Don't add more.

Like Ron said the definitive test is to drive until it is not cooling then pull over and open the hood (engine still running and A/C button still on) to see if the compressor is engaged or not.

This sounds like the rather common problem that the gap between the compressor clutch plate and the pulley is too wide. This will cause the compressor to not always engage, especially when hot.

The other really common problem on Civics is that the heater water valve on the firewall doesn't close all the way. Once the engine warms up, the heater and A/C will start fighting each other. The heater will win.

 

heater valve is a likely source of the problem as mk378 pointed out.

if the clutch is disengaging it might be the compressor relay going out.

 

Thanks folks. On my way home tonight I plan to pull over and check to see if the compressor is engaged and if the fan has stopped when the cold air stops blowing.
I added the refrigerant with only a low side guage. Unfortunately, I don't have a high side guage so can't test the pressure.
I appreciate your suggestions and I will keep you posted ........

 

Well, it looks like the problem is different than what I originally throught. The AC system had been blowing cold (at least for a short time) until last night. When I turned it on last night the air remained warm. I am thinking there must be a leak in the system somewhere. Any thoughts on how to check to confirm the problem now is a leak?
Thanks again,

 

It can still be the relay even after considering what happened. I would check that relay.

Was the compressor clutch engaged when the air was blowing warm? (there's short stud/bolt heads on the side of the compressor wheel and you'll see those spinning. The compressor clutch engaging is not to be confused with the part of the compressor that will still spin even though the clutch isn't engaged).