A water pressure gauge does not tell you the engine is overheating. It tells you the water pump is working. Granted, a malfunctioning water pump can cause overheating due to lack of cooling water but an engine can still overheat with a perfectly functioning water pump. Clogged water passages and stuck thermostats are prime causes of overheating. The key here is to install the gauge and at the same time install a new water pump (impeller or entire kit). Now record idle and WOT water pressure numbers. A reduction in these numbers over time provides the info you need to determine if water pump service is required. Add a water TEMPERATURE gauge to complete the protection package. But neither gauge is worth anything unless you look at them -- frequently.
