I'm having overheating trouble with a 2001 PT Cruiser recently given to me by my father-in-law.
The car never had trouble on the limited excursions he was taking it on, but ever since I drove it from Wilmington, NC, to Milwaukee, WI last January it's been overheating. The trouble actually started on that drive; the car pooped out in Indiana, and it turned out the coolant reservoir was dry. (Since he'd just flushed and refilled it, our theory is the coolant got too hot and boiled out of the reservoir, which is possible in that build.)
Since then we've flushed the radiator (twice), once with anti-rust additive to try to break up any blockages; replaced the water pump and the water outlet neck; replaced the thermostat and thermostat seal; and a input hose that was found to have a tiny leak. Nonetheless, the car had again already begun to run hot on 80 miles into a 400 mile drive yesterday -- the temperature gauge was three quarters of the way to the red line when we abandoned ship and got a rental. The coolant reservoir was still full, and filled to the fill/HOT line; so it just seems like any prolonged amount of highway driving is too much for the car to take.
The only thing left on the Top Five Reasons Your Car Overheats
list is the fan, which they say seems to be working. That's next on the list, I guess -- but if it's not that, any idea what it is?
Thanks so much!