Greetings . . .

I would check the thermostat to make sure it is actually cycling. I had the kind that 'fail open' in a pickup. With it stuck open the engine was fine at low revs, start/stop driving and idling - but with any amount constant of revs the water pump was circulating coolant to quickly through the open stat. Eventually the temperature would ratchet-up in the entire system to the point that the coolant in the rad was only a few degrees cooler then the coolant in block. All I could do was shut it down and let it cool. On the freeway I'd be good for 15 miles but the temp would just slowly climb . . .

regards,
stock49

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