Been having a recurring problem with my Camry (120k miles). When I first bought it eight years ago, I had a new thermostat put in. In the last couple of months, the temperature gauge has been climbing into the red after a couple of hours of highway driving. I took it to my mechanic and all he could find was a loose radiator cap. Last week, it happened again – and unlike before, the gauge wouldn’t go out of the red in city driving. I took it to a different mechanic who said it needed almost a gallon of antifreeze; he scoured it for hours but couldn’t find any leaks. He theorized that maybe it’s coming out of the exhaust, which he said would be bad news for the engine. It’s running fine now, but is this serious? Do I need a new thermostat?
An eight year old thermostat is an excellent candidate, and cheap and easy to change.
A 16 year old radiator cap is also an excellent candidate and cheap and easy to change.
A 16 year old radiator is another excellent candidate, a bit more expensive to change.
All of these components, and the possibility of the coolant being drawn in through a headgasket breech and burned, can be tested for.
Personally, I’d change the T-stat and radiator cap, test the cylinders for the ability to hold pressure (test of the headgasket), and perhaps…if there was no sign of a headgasket breech…drop in a new radiator.
Thanks very much!