Hi,
The hot weather has returned to Texas and with it higher than normal engine temperatures, at least when reading the water temp gauge. The car has always indicated water temps on the stock gauge between the "O" and "R" during the summer months. For the past week, the gauge has been reading between "A" and "L" even on constant drives where the car is in fifth gear at around 60mph with outside temps around 90F. It has been three years since the radiator fluid was changed (only 2000 miles) so I had the radiator flushed and refilled with new antifreeze. There was no indication of trash or buildup in the system. I also had the radiator cap, thermostat housing and thermostat replaced (192F Motorcraft) at the same time. The shop said the hoses appeared to still be in good shape (replaced with the radiator five years ago, 4000 miles).
Now the gauge reads at the "L" mark or just to the right of it. It does not appear that the hoses are collapsing (springs are installed) but there is no overflow going into the auxiliary tank once the engine is hot or showing to be near an overheat condition according to the gauge. I replaced the hose going from the cap to the tank as it was sucking close. Still no changes so I replaced the temp sensor gauge with a new replacement and no changes on the readings once the car warms up. I even set the aftermarket fan to operate 100% of the time and no change to the gauge readings after driving the car for about 15 minutes.
At this point without taking the car back to the shop for an expensive diagnosis, does anyone here have any ideas what could be causing this issue? I would assume at this point I am down to replacing the radiator or water pump next.
Any assistance would be greatly appreciated.