My 97 4.6 has 192k miles on it. I have had it since 168k. The a/c will blow iceeee cold. But sometimes it is several miles down the road before it starts blowin cold, other times it starts out cold instantly, after it was blowing cold and warmed up a little (on the same drive) i turned the temp. up a little and right back to cold, and it instantly got 15 degrees colder. Any ideas? The heater core was just replaced last week.

Thanks

 

Could this be caused by the freon being low? If it will get feezin cold sometimes then the freon is probably fine right? What do I need to buy to check my freon?

 

You need a low pressure side gauge. If it is hot in the cab, put the a/c on max with the blower on high, you should have 35-45psi. Does the compressor cycle on and off kinda fast? if so, it is probably low.

 

Honestly I cannot tell with this truck. I have driven pleanty of vehicles, all of which I can hear/feel/tell the compressor was cycling on and off, not with thist ruck though. Is it likely that this would be low freon though?

 

No one has seen anything like I am describing? Is there a more appropriate thread I can put this in?

 

Sounds more like your blend door may be broken.

Another possiblity is the system is icing. Next time it goes warm, pop the hood and see if the accumulator and nearby lines are severely frosted.

Steve

 

there is a blend door by the heater core. it mixes the cold and hot air to get the right temp that you chose with the dial. if the temp door is stuck or broke, you will be mixing hot air with the air cond air. might be a possibility if the heater was just work on.

 

...Yeah dont sound good as far as that route. Well as long as it still gets cold... Any suggestions.?