My Astra's (DTI 2.0L Year2000) temperature goes high when driving uphills or when depressing the acceleration pedal very tight when (speeding/"racing")
I've replaced the Thermostat by a fresh new one as well the the water flange (engine's coolant intake).
Now it reaches the temperature 90c faster & remains there if the road is straight. but on uphills it overheats & the fan(s) work especially the front one that I see that it works on low speed when the gauge just exceeds the 90c.
To be on the safe side with the fans I fed them with electricity (+ & -) and checked if their two speeds actually work and they do. So I assume that whenever the computer wants to turn on the high speed or the rare fan it can as it wants.
I took the radiator out and brought it to a specialist that disassembled it from the side and pushed a metallic thread all the way in it's pipes and extracted brown "junk" of calcium and what seemed to me as mud from all the pipes of the radiator (especially the lower ones). He did brilliant job & built the radiator again & tested it for any leak. I got the radiator fresh & clean, washed it again with water hose & made sure no brown water comes from it and installed it back in it's place.
Now it runs on clean water & the water doesn't become brown like before.
But the problem persists, only with stiffer/longer uphill drives it overheats above 90.
Otherwise it seems OK when driving anywhere in the the city or out of it, but just not uphills.
Can anyone advice on what might be happening here?
(I've never had such problem before with any car I had)