Hi everyone, I have a 2014 Chevy Cruze LTZ 1.4L Turbo with 150,000 miles (yes I drive A LOT) and until recently little to no problems Have always kept up with maintenance and oil changes. At around 140,000 miles I started hearing the radiator fan roaring like a jet engine and would only run at high speed (no low or medium). Took it in to 2 dealerships as well as a local mechanic and no one has been able to diagnose or repair the problem. I've had a new fan installed (problem still exists), I've tested the fan relays (all seem fine). So I currently am still living with a fan that only runs at high speed and sounds like a jet engine. About a month and a half ago, I the service light came on. I have a Blue Driver code reader, ran a scan and it showed code P2261, Turbocharger bypass Valve "A" Mechanical. Took my car into the dealership, mentioned that the fan was still only running like a jet engine plus the new service code. After looking at my car the service rep said I needed about $2200 worth of work on my car which included new Turbo and new water pump. Because I didn't have $2200 hundred right then I said I would have to wait on getting the repair done. Get my car back and not 10 minutes after leaving the dealership my car overheats (AC off message etc)/ I was closer to home than the dealership so I cranked the heat up and made it home, looked under the hood and had no coolant in the reservoir. (this wasn't a problem when I took the car in for repair). The next day I filled the reservoir with coolant, looked for leaks and took it to my local mechanic for him to check out. He came back later saying he drove it and that it didn't overheat and looked fine. Driving home from that mechanic, the car overheats again. This time it looked like coolant was seeping out of the seams on the reservoir, so I decided to replace the reservoir myself because I had just had it replaced a year and a half ago and found it was significantly cheaper to do myself and for the most part rather simple.
After this I started driving with my scan tool temp monitor on so I could watch the coolant temps. I noticed that after driving for about 15 mins the temp would rise to 234 then fall down to as low as 198. Then sometimes go up as high as 240/242/245 and then drop back down to the low 200's and every once and a while hit the 250 mark which would set off the overheating notifications, ac/off etc. but only for a few seconds and then the temp would drop back down. I changed out both of the coolant temp sensors and I changed out the thermostat. Still was having the same temp ranges and continued to have some coolant loss. Today I took it to yet another mechanic, this time we changed the water pump and replaced a seal where we discovered a coolant leak. Thought everything should be good now, right? wrong, tonight the temp ranges were up and down again, slowly inching higher each time and hit the 250 mark yet again but only for a few seconds. I don't seem to be losing coolant anymore but my engine is still getting to the overheating point. I've changed the coolant reservoir, the coolant sensors, the thermostat, the water pump, I've had the coolant system bled to get any air out. Checked and no leaks any longer that I can tell. What am I missing here? Anyone have any advice as to what might be the problem? What is the normal temp range of the engine coolant? And is it normal that it rises and falls constantly as mine is doing? Sorry for the long post but thought better to give as much info I had upfront