Hyundai XG350 Not Cooling

[pupfield]

My 2005 Hyundai XG350 began to blow warm, not a big deal for an older car in the south. Gauges showed normal low side (40-50PSI) and high side was high (300+ at driving RPM). Figured it was a plugged / bad expansion valve. Replaced it. Added freon. Seemed a little low on both gauges, added a bit more until low side was 45, high side was around 235 at idle (it's hot today), High goes to 275-325 at highway RPM. Seems still too high and output is only 70 degrees at best. Condenser air flow is good, fan operating normally.

Now what?

[Tim]

Charge to factory specs. 45 psi is high for an expansion block system.

[pupfield]

Do you happen to have those?

[Tim]

600grams of R134a.