If, in the future, I find that the Block Tester test is accurate and it is verified that combustion gas leakage frequently causes overheats, I will probably begin recommending Block Testers as a General Maintenance test for overheats and unexplained coolant loss. As I read overheat emails from Troubleshooters. Com visitors, I'm struck by the heartaches caused by even a single overheat incident. Overheats can break head gaskets, and broken head gaskets can cause additional overheating, broken starters, broken solinoids and broken flywheels. Extreme overheats, or moderate overheats on cars with aluminum heads, can destroy the heads.
Prevention starts with a temperature guage.
Do not buy a car without a working temperature guage. If you own a car with only an idiot light for temperature, consider having a guage installed. Once you have a working guage, glance at it at least once every 10 minutes, or any time the car's operation seems strange. Read Steve Litt's Overheating Guide . It discusses many other tactics and strategies for overheating diagnosis, as well as a discussion on safety.