Hey all, looking for some advice. Been to the mechanic twice now and am still having issues. Bought this truck used about two months ago, 150000km, seemingly great shape. Fully safetied. Recently had a big coolant leak. Diagnosed as the water pump assembly. Replaced it all. Then engine light comes on. I can’t remember the code, but the mechanic says he’s never seen it in his life. I’ll drive for an hour and the engine temp stays on cold. Then out of nowhere shoots up to passed the end of hot. One day I’m driving and I can put the heat on and it’s nice and toasty. The next day, nothing but cold air comes out of every setting, even after warming up and then driving. Back and forth. Sometimes the dash light flicker and go dim, then randomly brighten again after awhile. Been back to the shop and they say there’s no coolant leak and they don’t know the issue. Thoughts? 🙏