What color engine smoke is this?

Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
Link to video here: https://photos.app.goo.gl/7z5Po6cXBYaYY6RQ7

After the long saga of my fuel injectors, we ended up just having the original ones sent off for service and reinstalled. The yard did a valve adjustment at that time as well. Now, my engine does this upon starting... it’s always spat the white smoke you’d expect when an old diesel starts, but this seems different. Is that blue smoke, or just more white smoke? Are the new injectors and valve adjustment just pushing more fuel through than the engine can handle?

it clears up after starting when I drop the throttle back to idle. Underway, however, we seem to be making more smoke than we used to, and white smoke while motoring was the reason I embarked on this project in the first place. Seems after all this, it’s worse!

Engine sounds great while motoring and pushes the boat fine otherwise.
 

Alan Gomes

Sustaining Member
Link to video here: https://photos.app.goo.gl/7z5Po6cXBYaYY6RQ7

After the long saga of my fuel injectors, we ended up just having the original ones sent off for service and reinstalled. The yard did a valve adjustment at that time as well. Now, my engine does this upon starting... it’s always spat the white smoke you’d expect when an old diesel starts, but this seems different. Is that blue smoke, or just more white smoke? Are the new injectors and valve adjustment just pushing more fuel through than the engine can handle?

it clears up after starting when I drop the throttle back to idle. Underway, however, we seem to be making more smoke than we used to, and white smoke while motoring was the reason I embarked on this project in the first place. Seems after all this, it’s worse!

Engine sounds great while motoring and pushes the boat fine otherwise.
Does your engine seem to be consuming any oil? If so, at what rate?
 

Baslin

Member III
Its hard to tell what color smoke that is but it appears to be more white than blue.

White Smoke: Is a condition of small particles of unburned/or partially burned fuel. Usually more common when the engine is cold and the rings haven't fully seated and sealed and there isnt enough heat inside for a complete burn. White smoke could also be water or steam. If it is burning coolant from lets say a blown head gasket, you would have a bit of a sweet smell from the exhaust and also loss of coolant over time. Maybe an overheating condition as well. I have also seen white smoke caused by restricted fuel filters causing an improper fuel mixture.

Black Smoke: This is an over fueling condition. Could be a stuck or leaking injector, clogged air inlet, or a propeller that is over propped where the engine is dumping in fuel but is being lugged or sluggish.

Blue Smoke: Blue smoke is oil that has entered into the combustion chamber and is being burned. The most common cause of this would be worn cylinder rings, leaking head gasket or valve seals that are leaking and causing oil to enter the combustion chamber around the valve guides.

I have been chasing a bit of what appears to me as white smoke in our engine, especially at higher engine RPM's and higher engine loads. I think it has to do with a restricted heat exchanger and its more of steam than anything. At least thats what I'm leaning towards. I will know once I remove and clean the heat exchanger.

When you had the yard do a valve adjustment, did they just check and set the valve lash?....Setting valve lash is done with a feeler gauge. The distance is measured between the rocker arm tip and the valve stem when each cylinder is just at TDC (top dead center) and both intake and exhaust valves are closed. It is a fairly easy adjustment once the valve cover is off. This adjustment corrects the range of valve timing. Like Christian said, I would get with the yard mechanic and see what they say.

Hope this helps,

Blake

Hope this helps.
 

footrope

Contributing Partner
Blogs Author
Can you get a whiff of the smoke? Oil has an unmistakable odor. Diesel is sort of oily anyway and a diesel might give off a little gray smoke for awhile after startup, particularly if you had a hard time starting it. Sometimes excess unburnt fuel will show on the surface of the water for a few seconds.

Steam, when it is light and you can see through it, probably comes from salt water in the muffler, dissipates to nothing quite rapidly.

Smoke lingers in the breeze longer.

White smoke that is bright white, like a cloud, and opaque, is probably from coolant. That exhaust in your video does not look like coolant but the color is otherwise hard to tell.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Steam or smoke?

Evidence of video insufficient. Also, camera phone was held vertically, which is a contravention of Old Guy Rule which states that In the making of videos not intended for Instagram or mobile viewing, or for selfies, or for any other subject not specifically cited in the Dead Sea Scrolls, the device is to be held in a horizontal plane so as to provide an aspect ratio wider than the human nose.

My diesel steams a little on startup. It seems to be related to the dew point. I have tried to come up with a measurement steam/smoke, but my claim of no more than five feet for steam, and that smoke carries further, is a shot in the dark.

 

Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
Agreed I need to get back with the mechanic. Here’s a landscape video of us presently underway in light winds. I think I burned a little oil on this cruise but didn’t take good enough notes to be sure, unfortunately. Still sounds good and no overheating (at least none that the temp gauge shows).

New vid:

 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
That sure looks like steam to me.

How's the volume of water out the exhaust? Restricted flow means more steam. Apologies if that's already been discussed.
 

Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
That sure looks like steam to me.

How's the volume of water out the exhaust? Restricted flow means more steam. Apologies if that's already been discussed.
Volume seems OK to me, but it does sometimes seem a bit gaspy, and the water comes out more like an aerosol spray rather than the chugging sloshes of water I see out of other exhausts. Kind of high pressure. I recently had the exchanger off (which looked pretty good to me). I did a visual inspection of the mixing elbow but it looked OK for a very cursory inspection. Maybe something is gummy further up the line...
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
I made a video of my "normal" exhaust for overall comparisons.

 

Geoff W.

Makes Up For It With Enthusiasm
Blogs Author
That really doesn't look too different from my exhaust, actually.

One item of note, upon our recent return from cruising, after a day being thrown around in the various tidal rips and washing machine currents of Puget Sound, the engine died, in the middle of the shipping lanes without wind, no less. After ripping apart the boat and changing the Racor, it turned out to be a blockage in the fuel tank pickup line. Blowing it out returned the engine to normal operation.

Additionally, after my recently long haulout, I've noticed the fuel pump ticked much, much faster than it used to -- up to 2 ticks per second or so, whereas normal operation used to be 5-6 seconds between ticks. I attributed this to cutting out the trailer plugs and improving the electrical connection, but now that the tank has been blown free, it is back to its normal, slower rate of tick.

Perhaps the engine has been slightly fuel starved for a while now -- I haven't read that as a cause of fuel-related white smoke, but maybe?
 
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