Here's something I learned the other day. If your car is overheating, don't automatically assume that your thermostat has gone bad.
Friday, I had a doctor's appointment right after picking "The Boy" up from school. My truck was running hot (which started the day before) so I deduced that my thermostat had gone bad. I went to the auto parts store from doctor's office, picked up a new thermostat & gasket, then went home so my truck could cool off enough for me to do the swap out (WARNING- Never try to swap out a thermostat while the engine is hot. You will get burned).
While the truck was cooling off, I mowed the grass and went out to eat with my wife & grandchildren. When we got home, she took the grandkids home while I went about to work on the truck.
My wife advised me to reread the instructions on how to do it in the Haynes Automotive Repair manual that I have for my truck. Hello, I'm a guy. Guys don't read instructions. I decided to anyway. In the book, it says that before you condemn you thermostat, check the trouble shooting page for more reasons your vehicle could be overheating.
When I did that, one of the entries was "You radiator cap may not be sealed properly." I went out to check. Not only was the radiator cap not sealed properly, the seal was almost non-existent. I called my wife and explained what I had found. I also told her that the auto parts store closed in 20 minutes.
She got home & we dashed off to the store. I walked in with four minutes to spare. The same employee who had sold me the thermostat was still there. Looking at the radiator cap, he exclaimed "Wow, I'll bet that there's your problem." I exchanged the thermostat & gasket for the radiator cap and came out $1.29 ahead. When I replaced the cap (and added more coolant) the truck ran like a top.
BTW- on a related note, If your vehicle occasionally won't start after you've driven it, you battery may have a dead cell. I replaced my truck battery on Thursday for that reason. I got good service from that battery, seeing that it was older than my truck. I drive a 1992 Silverado, and the battery was purchased in 1984 (It was in the truck when I bought it).
6 years ago