Overheated: What Should I Replace?
My wife just drove our '02 330i while it was overheated. She's not sure how long she drove it that way, maybe a couple miles (which I know is more than enough). When I tried to start it after she got home (maybe that wasn't smart, but I wanted to see what it did) the temp needle immediately pegged to the right, the engine clicked loudly, ran rough, and then stalled. I was certain it was DOA.
However, I went out the next day and it started fine with the temp needle right in the middle. I topped the water off and bled the coolant then took it for a short drive and it had plenty of power and drove smoothly for a 30 minute drive. Water is steaming out of a crack in the side of the radiator, but I know that's an easy fix.
I had known there was a slow coolant leak before, but I couldn't tell where it was coming from so I recently replaced the Thermostat, Water Pump (with an EMP Stewart), and both hoses. That didn't solve the leak, but it was very slow so I procrastinated on replacing the radiator and expansion tank (kicking myself now.)
Questions: When I replace the radiator and expansion tank, should I repair the following?:
1. Since it over heated after those repairs, do I still need replace the thermostat even though it's almost new? (I know with older engines this was always advised, but the thermostat seems to be operating normally.)
2. Should I tackle the fan clutch while I'm at it?
3. Do I need to change the oil or should the fully synthetic stuff be okay with the brief overheat? (I changed it less than 1k miles ago.)
4. Would anything else be damaged? Please don't say the new $200 water pump.
5. Is there still a good chance that the top end is fried and I would just be wasting my money on all of the above repairs?
Thanks gang. Chris