2008 Expedition XLT - 200,000+ miles, located in South Louisiana.

AC blows cool, but not cold air. Started last Summer and is continuing this Summer. Took to mechanic yesterday, He says that at idle, gauges show pressure for high and low side are spot on. But if he gives any throttle, the high side goes to 350. He suspects a clog. Says there is no orifice tube, just expansion valve and may have to get to the coil in the cabin to get it unclogged.

I do have an appt with the Ford dealership next Tuesday, but just wanted to check on the above info. I know its not very detailed, but just trying to get an idea of what kind of $$$ is involved.
Besides the orifice tube, that may or may not exist - what are common clog points? How difficult to change/clean out?

 

Might be a restriction in the system, but it also could be insufficient heat rejection from the condenser due to not enough airflow through it. Hit the condenser with a cold water spray and see if the high side pressure drops.

 

With that mileage it could be the dessicant bag came apart and contaminated the system. Expect to spend $$$ if thats the case.