White Smoke from 1995-3GM30F

Status
Not open for further replies.
J

James Dugan

While comming in this weekend, we were at 2800 RPM's heading directly into 8 knot wind pulling my 8' dingy. For a breif period of time we saw white smoke comming out of the exhaust. I stopped the engine and checked the oil and cooling water, both ok. Trying to be carefull we started back @ 2500 RPS with no more white smoke. I had just cleaned a large amount of barnacles and slime off the water line of the boat. Last season when we pulled for the season, the prop has about 1/2 of the blade pitch covered with barnacles. I have a diver cleaning the prop and shaft this week. Could the barnacles on the prop have caused the white smoke? Please advise.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
white smoke or steam?

It is the time of year when you get lots of folks mistaking steam (normal in cool weather) with white smoke.
Just like your car "smokes" in the morning. Just note if the "smoke" dissipates or drifts out.
Usually a fouled prop or bottom will make the engine produce black smoke. White smoke is a sign of completely unburned fuel or an anti freeze leak into the exhaust manifold. If it is an anti leak you will get huge volumes of white smoke and that antifreeze smell. Unburned fuel would be an indication of no compression which would be indicated by a rough running engine.
My vote is for steam.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
White smoke is normally associated with coolant being burnt in the cylinders. But depending on where you live (temp of the water) it surely could be steam.
 
Feb 10, 2007
213
Hunter Legend 40.5 Coconut Grove, FL
My friend's 38 was making "White smoke", happened to be the raw water impeller GONE, and the exhaust is very hot making water steam... Check your impeller..just in case...
 

RobJ74

.
Mar 9, 2008
23
Hunter 29.5 Captain's Cove, Ladner BC
Marco described what happened to me this spring. Partially blocked intake from seaweed (that didn't even make it to the raw water strainer) gave me partial cooling, cooked my impeller. It resulted in partial water coming out and steam. I thought it was white smoke... turns out it was steam.

Rule of thumb, black smoke is fuel, white is coolant/water.
 

RobJ74

.
Mar 9, 2008
23
Hunter 29.5 Captain's Cove, Ladner BC
One more thing. I also pulled a coolant hose off to check for flow from the raw water pump using a cordless drill with a socket on the end to rotate. I did get water pumping through that way and it sent me down the wrong road for a short spell... turns out it was just not enough water. Inspect the impeller lobes carefully... mine looked ok at first glance but it was definitely over heated and damaged upon closer inspection. Let us know how you make out.
 
J

James Dugan

White Smoke Problem Found

The intake thru-hull was almost completely covered with slime and with barnicles so the flow of water reaching the engine was too small. The diver cleaned the prop and intakes so now the flow is ok and she still purrs like a kitten! Great engine. Thanks for the comments and help.
 
Status
Not open for further replies.