01 Infiniti I30t overheating

[SOCAL805]

I had posted this issue a while back. Quick recap- My I30t has over 200,000 miles, automatic, etc. Last year in the summer my car would over heat only when stuck in traffic with over 90 degrees temp or when hot outside and going up the grapevine. You guys provided many causes. Therefore around 5 months ago I replaced the radiator, thermostat, radiator cap, top and lower hoses. Looked good ran good (except for a deteriorated bushing at the lower control arm which caused a steering wheel jerk after making a right turn). Last Sunday it was hot in socal and I was driving back home towards Bakersfield. I had the same issue...stuck in traffic, car started overheating. Turned off the AC and it was back to normal. Before going up the grapevine. I pulled over and checked the fluids, everything seemed ok. Went up the grapevine, and as long as I drove slowly up slopes and didn't get any traffic. I was able to get home safely and even have the AC on (except for when going up a steep hill). Therefore what else can be causing the overheating? I believe it might be the water pump. But before I go that rout, any other ideas?

F.y.I - oil change was done recently. Car does not overheat in cool weather. Just replaced my right lower control arm, both tie rods. Have a power steering high pressure hose which I've yet to install. Once I fix the over heating issue. Will install high pressure hose (currently have a small leak for the last 2 years, thanks to Lucas Power steering fluids which stop a big leak), New spark plugs, and shocks. Thanks for any help provided.

[loystock]

Try BG Coolant Flush first. If problem persisted then it's the water pump.

[SOCAL805]

Even if my radiator is less then 4 months old?