Mercruiser Sterndrive Information
Mercruiser Parts Mercruiser Help Mercruiser Manuals Mercruiser Tools Mercruiser Sterndrives Mercruiser Board Contact
My Engine Blows Steam Out the Exhaust

Steam appears as billowy white smoke that disappears and has low odor. If the white smoke has a strong fuel smell it might be excess fuel burning and not really steam.

Steam is usually noticed on boats that have direct exhaust. Boats with through-prop exhaust can steam too but it would only be evident if the boat were not in the water.

A little steam is normal. All exhaust will show a little stean now and then especially on cold mornings. If you get excessive steam it may indicate a problem.

Two basic things can cause too much steam.

1. Overheating
2. Leaking Exhaust Manifolds, Risers or Gaskets

1. Overheating causes the exiting exhaust water to turn into steam. A bad Water Pump, a plugged exhaust manifold or elbow or even a bad thermostat can cause the engine to run hot and steam.

2. Old exhaust manifolds and exhaust elbows can get plugged with rust or the can develop internal water leaks. If the xhaust is bad to the point that it is causing steam, they should be replaced ASAP. Bad exhaust will ruin a perfectly good engine.
















Safety
Boats can explode. Moving parts can rip your off your fingers. Hot exhaust can burn you to the bone and props can slice you up. One spark near a battery can cause an explosion. You can never be too careful. Remove the battery from the boat before working with fuel. Always disconnect the batteries negative terminal first. Clean up any spilt fuel and let ALL of the fumes dissipate before installing the battery and starting the motor. Pulleys and Belts can grab your clothes and hair. Don't wear loose clothing and keep your hair up under a hat. Always wear safety glasses. Be smart.
Sterndrive-Information
Change your Alpha Gear Lube
Change your Bravo Gear Lube
Why does my drive lube have white streaks?
Why does my drive lube have gray mush?
Replace Your Alpha One Water Pump
Replace your Alpha Gen II Water Pump
Rebuild your Bravo Raw Water Pump

Troubleshoot & Replace your Alpha Shift Cable
Troubleshoot & Replace your Bravo Shift Cable

Replace your Alpha One Bellows & Gimbal Bearing
Replace your Alpha Gen II Bellows & Gimbal bearing
Replace your Bravo Bellows & Gimbal Bearing
Why does my drive "Growl" when I turn?
Water is leaking into my boat from the transom

Replacing your Trim Sender Switches
My Trim doesn't work but my Trailer Switch does
My Trim Gauge is Pegged

Rebuild your Alpha One Upper Driveshaft Housing Assembly
Rebuild your Alpha One Lower Gear Housing Assembly

Check your Engine Alignment
Check for Excessive Steering Play
Troubleshoot an Overheating Problem
Should I remove my thermostat?
Why do I overheat when going fast?
Troubleshoot a No-Crank Condition
Troubleshoot a No-Start Condition
My Engine Backfires and/or Surges and has Lack of Power
What is an Anti-Syphon Valve?
My Engine blows Steam from the Exhaust
Why do I hear a "clakity" sound while at idle?
Exhaust Manifolds...IMPORTANT Information
How do I Winterize my engine?

What is Galvanic Corrosion?
I have a Bravo III Galvanic Corrosion Problem
What is a Mercathode?
All about Zinc Anodes
How do I check my carburetor?
What carburetor do I have? A Rochester or a Mercarb?
I have water in my fuel
My fuel smells like varnish
My fuel is old
My engine has been sitting for several months without being run.

I have a Mercruiser 470, 485, 488, 190, 3.7L Engine
I have coolant dripping from the front of my engine
Can I install a regular Alternator instead of the Stator-Rotor?


©2004 Sterndrive Shop •EmailAbout UsHome Mercruiser HelpShop ManualsMessage BoardContact