So Phoenix is tipping over the 100F mark....gonna be 115F is no time and the 300TE is starting to struggle.

Normal driving in 100F is around the 100-105C mark, so its definitely running hot.
Even on the freeway it won't decline.

Coolant level is good
Reservoir cap holds pressure
Just replaced thermostat last week with 79C version (Bosch)
Water pump replaced in 2009 when I did head gasket (Graf)
Fan Clutch works.

I replaced the radiator back in 2006 with a "Metrix" brand one...it was the cheapest go figure...

Think the cheap radiator has crapped out?

I know the 103's cooling system is capable at 115F since my 260E's did perfectly fine last summer and sat around 90-95F tops. I have Nissens in her, so I'll definitely go with Nissens.

Anything else I should consider or test before replacing the radiator?

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