Boat Engine Overheating Repair
Overheat alarm, weak tell-tale, or rising temperature? We repair impellers, thermostats, heat exchangers, and exhaust manifolds and risers before overheating damages the engine.
Ethan, the owner and mechanic, answers the phone · Open 7 days a week
- Same / next day availability
- On-site & marina service
Boat Engine Overheating Is a Warning You Can't Ignore
Overheating usually starts small: a worn impeller, a stuck thermostat, a clogged passage. Left alone, it can warp heads, burn pistons, and let water into the engine. We find the cause and fix it at your dock.
Trusted by boat owners across South Florida
Read our Google reviewsNo call center. No front desk.
When You Call, the Owner Picks Up
Every call goes straight to Ethan, the owner of EG Marine Services and the mechanic who does the work. There’s no receptionist taking a message and no waiting on a callback from someone who’s never seen your boat.
Tell him what’s going on: the alarm on the display, the noise at idle, the engine that won’t turn over. Ethan knows Yamaha, Suzuki, Mercury, and the rest of what runs in South Florida inside and out, so you’ll usually get a straight answer on the first call, whether that’s something you can check yourself or a visit to your dock.
- Straight answers, not a script
- Diagnostic questions answered on the phone
- Honest advice, even when the fix is simple
- The person you talk to is the one who shows up
Ethan
Marine mechanic
Describe what the boat is doing and get a real answer from the mechanic, not a message taker.
Call Ethan: 786-351-5363Open 7 days a week
Engine running hot? Call Ethan before you run it again.
Call 786-351-5363Signs of a Boat Engine Cooling Problem
- Overheat alarm or high temperature on the gauge
- Weak or no tell-tale stream on an outboard
- Steam or hot exhaust smell
- Engine goes into reduced power
- Coolant loss on closed-cooled inboards
- Rust or water stains on manifolds
Real Boat Engine Overheating Jobs
Burnt water pump impellers
Impellers that skipped their yearly change come apart and send pieces into the cooling system. On one MerCruiser, the last mechanic pulled the Bravo outdrive thinking that's where the impeller was. On that engine it's on the motor. See water pump impeller replacement.
Heat exchanger
A motor losing coolant and overheating had a bad heat exchanger. It was replaced and the boat was back running.
Exhaust manifolds and risers
Corroded manifolds and risers cause overheating and can leak water into the engine. We've replaced many on MerCruiser and Volvo inboards.
Cracked fittings and clogged passages
A cracked water inlet fitting, a clogged port manifold fitting, and a clogged tell-tale on a Suzuki 350 were each the whole cause of an overheat.
Our Overheating Repair Process
- 01
Check Water Flow
We check intake, tell-tale, and water pressure.
- 02
Inspect the Pump and Thermostats
We pull the impeller and thermostats and check the housing.
- 03
Check Manifolds and Exchangers
On inboards we inspect manifolds, risers, elbows, and the heat exchanger.
- 04
Repair and Run
We replace what failed and run the engine to temperature to confirm it holds.
From the Job Log
Burnt outboard water pump impeller with missing vanes 
Corroded old engine thermostat next to a new one 
Raw water pump and hoses on a boat being serviced 
Corroded exhaust manifold removed from an inboard engine
Stop the Overheating
Shut down and call. Running an overheating engine can turn a small repair into a new motor.
Call Ethan directly786-351-5363Open 7 days a week · No call center or front desk, you talk to the person doing the work
- Impeller and water pump service
- Thermostats and sensors
- Heat exchanger and coolant service
- Exhaust manifolds and risers
Prefer a free quote?
Leave your number and we’ll call you back.
Boat Engine Overheating Repair FAQs
How often should I replace my water pump impeller?
Once a year or every 100 hours, whichever comes first, even if the boat doesn't get used much. We replaced the first impeller on a 2019 Yamaha that only had 150 hours in six years and the owner thought it didn't need service.
Why is my outboard not peeing?
A weak or missing tell-tale stream usually means a clogged tell-tale hose, a worn impeller, or a blockage in the cooling passages. Check it quickly, because it can lead to overheating.
How often do exhaust manifolds and risers need replacing?
On inboards and sterndrives, every 4 to 6 years is a good rule. Corroded manifolds and risers can leak water back into the engine.
Can I replace my own manifolds?
We don't recommend it. We've seen an owner replace his own exhaust manifolds incorrectly, which cost him a new motor.
Areas We Serve
Our mobile marine mechanics travel to marinas, private docks, and waterfront homes from Boca Raton to Islamorada. Nearby but not listed? Reach out to confirm availability in your area.