Overheating is the #1 cause of catastrophic engine damage on the Bay. Shut the engine down within 30 seconds of seeing high temp — a melted impeller turns into a bent rod and a $20k repair fast.
What to Check
1
Raw water flow
Verify water is coming out the exhaust at the dock. No flow = clogged intake, failed impeller, or seacock closed.
2
Impeller
Marine impellers should be replaced every season. A torn or worn impeller is the most common overheating cause.
3
Heat exchanger
Salt and scale buildup blocks heat transfer. Most heat exchangers need acid cleaning every 3–5 years.
4
Thermostat
Stuck-closed thermostats prevent coolant flow. Cheap part, easy fix.
5
Belts
A slipping or broken raw-water pump belt stops cooling immediately.
When to Call Us
If you've checked impeller and seacock and the engine still runs hot, call us — it's likely a heat exchanger blockage or thermostat that needs proper service before you damage the engine.