overheat going uphill ONLY
I have been struggling with a cooling issue for aver a year now and cannot figure this out. I have a 1998 ram 1500 5.2 4x4 5spd. It runs at about 180 and can idle with the AC on in the summer without getting above 210 all day. When ever I go up a long steep grade the temperature gauge climbs quickly and pegs, warning lights come. The coolant level never goes down and it doesn’t boil over or steam. It quickly cools down as soon as I begin heading downhill or flat road. I have a 180 degree thermostat in but I began having this problem when I replaced it last year.
Things that I have replaced to try to solve this:
Coolant sending unit
Plenum gasket replaced
Bled air from system by parking on an incline with rad cap off.
Is it possible that the water pump is not performing well enough to move water through the systems when the vehicle is on a steep grade with the nose up?
I know that the Cat converter is bad from the rattling sound it makes, Can backpressure cause and overheat like this if the engine is under load? It does not pull hills with much power but my last truck was a Cummins 5.9 so I would expect much less performance here.
98 1500 5.2 V8 QC Manual. 3"lif 2500 springs pro comp aal,Cat Delete, Cool Vue CAI. 3.55