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Jud - s/v Sputnik

Diesel - white “smoke” and possible non-firing cylinder?

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Quick question if anyone has an insight.

Boat motoring much slower than usual —could be fouled hull and/or prop (haven’t checked yet - will soon) - boat basically hasn’t moved since December, but it was bottom painted spring 2018, and prop and bottom of keel/rudder (only) scraped by diver this spring....so I don’t *think*  fouling is that bad.

Exhaust looks whiter than I remember.  This colour suggests either steam (leaking head gasket/coolant vaporizing), or atomized but unburnt fuel b/c of an injector issue.

Am wondering about latter possibility due to lack of power (really struggling for 3+  kts at 2000 RPMs in pretty flat water/no waves/minimal current).  Anyone know what else (other than lack of power/white “smoke”) would indicate non-firing cylinder?  (Engine recently had complete rebuild, including replacing one injector and servicing other two.)  Thing is, though, if an injector issue/non-firing cylinder and thus unburnt, atomized fuel is being expelled, wouldn’t there be a sheen on water at exhaust?

Other than white exhaust “smoke” and less power than usual, down anyone know what would be other telltale signs of non-firing cylinder?

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I had similar conditions about a year ago, except my exhaust was more grey because the remaining two cylinders were working hard and making black smoke that mixed with the white.  I couldn't get the boat up to hull speed without more smoke than I liked, but it seemed to motor pretty well at 5 knots (where I don't need much power). 

I had a mechanic check it out and they did a full injector swap and some other minor work. It runs great now. 

Another symptom was that it was pretty hard starting and would release a big cloud of black smoke just after starting. That all cleared up with new injectors. 

I should add that a year earlier I had replaced the injector nozzles myself (much cheaper), but didn't have a diesel shop adjust the nozzle pressure. That turned out to be a mistake, and in the end it was better to just have a more experienced mechanic do the work (and check over what else I'd done, all of which was fine). 

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Pull all the plugs. If one cylinder isn't firing because of a problem in the injector or the rail or manifold or ignition system ... you'll see that plug will look different depending on your air-fuel mix ... either covered in soot or sometimes burned. I had the loss of power and white smoke once in a gas engine, one injector had failed and I replaced it without cleaning out the rail ... dumb mistake. Use a magnifying glass on the emitter and collector, sometimes you can see where the spark is firing against the oxidized steel, which is a decent indication that it's fuel delivery.

The old school guys can look at a plug and tell you as much as an engine diagnostic computer.

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23 minutes ago, mikewof said:

Pull all the plugs. If one cylinder isn't firing because of a problem in the injector or the rail or manifold or ignition system ... you'll see that plug will look different depending on your air-fuel mix ... either covered in soot or sometimes burned. I had the loss of power and white smoke once in a gas engine, one injector had failed and I replaced it without cleaning out the rail ... dumb mistake. Use a magnifying glass on the emitter and collector, sometimes you can see where the spark is firing against the oxidized steel, which is a decent indication that it's fuel delivery.

The old school guys can look at a plug and tell you as much as an engine diagnostic computer.

Diesel Mike. 

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1 hour ago, Innocent Bystander said:

Diesel Mike. 

Forget it, he's rollin.

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1 hour ago, Innocent Bystander said:

Diesel Mike. 

The glow plug will give a clue to what's happening in there.

But how did you know it's diesel? I read the OP three times and I didn't know for sure. The fuel path still has injectors and the rail.

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Alternatively, crack one injector, see if the engine runs worse or not. The one that doesn't matter is the suspicious one. Beware diesel running down the bilge

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1 hour ago, IStream said:

Thread title.

Maybe needs a better hint?  And a really fouled prob either barnacles or wrapped crap on it will really slow you down. Was on a buddy's boat when we lost propulsion and turned out had plastic wrapped the size of a basketball. Wondered if had dropped the prob, tranny gone, whatever. After a diver cleaned it (as well as the prop) easily got another knot in speed. Diver was a buddy and told me it hadn't been cleaned in some time. 

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2 hours ago, mikewof said:

The glow plug will give a clue to what's happening in there.

But how did you know it's diesel? I read the OP three times and I didn't know for sure. The fuel path still has injectors and the rail.

Sorry - I didn’t realize I hadn’t made clear in my post (just title) that it’s a diesel.

Alas, no glow plugs on this engine (Volvo 2003).  Tracks for your time and thoughts, though...

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12 hours ago, Jud - s/v Sputnik said:

Sorry - I didn’t realize I hadn’t made clear in my post (just title) that it’s a diesel.

Alas, no glow plugs on this engine (Volvo 2003).  Tracks for your time and thoughts, though...

Snake bit me. Best of luck in finding it. The last diesel I drove had the loss of power but the smoke wasn't white. The valve seals were worn way past usefulness, and contaminated with fuel debris, probably from a bad filter.

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If it takes more than a few revs to get started you may have a bad diaphragm or seal in your fuel pump and sucking just enough engine oil to make your smoke.   If they rebuilt the block and head, but uninstalled/reinstalled the fuel pump that might be one to study.  

Late timing does white smoke too, and is more of the hanging lingering type than too much fuel.

But I'd put a tester on your coolant cap and verify that you aren't making pressure from a head gasket leak, as a diesel without glow plugs doesn't take much of a warp to have a one way leaker on a head gasket. 

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I'd check your mixing elbow. It's a lot easier to do than some of the other suggestions and while it's less likely to be the problem, if it does turn out to be blocked, you can fix it with a hammer - which is my preferred method of fixing anything.

The "white smoke" could be steam coming from flash-boiling your raw water cooling. That leaves a rock hard salty/carbonny deposit in the mixing elbow that chokes off the exhaust and increases the backpressure. This makes evacuating the cylinders harder to achieve and leads to poor performance.

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On 7/21/2019 at 1:34 PM, mikewof said:

Pull all the plugs. If one cylinder isn't firing because of a problem in the injector or the rail or manifold or ignition system ... you'll see that plug will look different depending on your air-fuel mix ... either covered in soot or sometimes burned. I had the loss of power and white smoke once in a gas engine, one injector had failed and I replaced it without cleaning out the rail ... dumb mistake. Use a magnifying glass on the emitter and collector, sometimes you can see where the spark is firing against the oxidized steel, which is a decent indication that it's fuel delivery.

The old school guys can look at a plug and tell you as much as an engine diagnostic computer.

 

23 hours ago, Innocent Bystander said:

Diesel Mike. 

 

22 hours ago, IStream said:

Forget it, he's rollin.

He’d better check the points, too!  And the Fetzer Bearings!

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The nut behind the wheel might need to be torqued also.

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28 minutes ago, silent bob said:

He’d better check the points, too!  And the Fetzer Bearings!

PEBKAC

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If it's steam, it should just kind of disappear as it condenses. Smoke will drift away.

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