Yanmar 3GM30F heavy smoke at high RPM

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system
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Kairos1
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Joined: Mon Dec 14, 2020 2:01 pm

Yanmar 3GM30F heavy smoke at high RPM

Post by Kairos1 »

All,
Sorry if this has been posted before. However I wanted to share with you a recent experience that I had with my Yanmar 3GM30F. Anytime I would try to go over 2600 RPM I would blow heavy smoke. After many hours and many dollars, I discovered the issue was caused by the mechanical fuel lifter pump. It seems to be a common problem with these pumps. The problem is when the diaphragm becomes compromised and the engine oil is at full capacity, oil is is allowed to migrate into the fuel system. Once I changed the pump it resolved the issue. It should be noted that the pump I replaced was new out of the box.
"Kairos"
1988 F36- Hull#88
Pawtuxet Cove, RI

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philipl
Posts: 95
Joined: Mon Jul 27, 2009 3:12 pm
Location: Manchester by the Sea, MA

Re: Yanmar 3GM30F heavy smoke at high RPM

Post by philipl »

That is definitely worth noting. Not something that I would have connected.
Thank you for posting.
Philip Leahy
F-38 ex Manchester, MA.

dwight
Posts: 63
Joined: Sun Dec 07, 2008 3:41 pm
Location: Newport, RI
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Re: Yanmar 3GM30F heavy smoke at high RPM

Post by dwight »

Note that the smoke produced by burning engine oil has a blue tinge while smoke produced by an overloaded diesel engine is black. White "smoke" is actually either unburned diesel fuel or coolant vapor, the difference is the smell. Knowing these differences can help with the troubleshooting.
Dwight Escalera
Accredited Marine Surveyor, SAMS #1024
former engineer at Freedom Yachts
former owner F36-71
Wakefield, RI

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philipl
Posts: 95
Joined: Mon Jul 27, 2009 3:12 pm
Location: Manchester by the Sea, MA

Re: Yanmar 3GM30F heavy smoke at high RPM

Post by philipl »

I am getting heavy white smoke on start up. Once running it goes away. I have no problems starting the engine. I had a mechanic replace the head gasket and clean the injectors. I replaced the elbow and installed a new lift pump. Any thoughts?
Philip Leahy
F-38 ex Manchester, MA.

BillSmith
Posts: 77
Joined: Tue May 24, 2016 7:56 am
Location: San Mateo, CA

Re: Yanmar 3GM30F heavy smoke at high RPM

Post by BillSmith »

Keep the glow plugs engaged longer and drop warmup speed.

We ALWAYS had copious white smoke on startup. No other time. Idle would be rough. Kept rocker switch depressed longer and cured both symptoms. Could reduce throttle to at or near straight up (neutral idle speed) and reduced smoke dramatically.

Your mileage/smoke may vary.

G'luck.

Engine is a Perkins M30, three cylinder ~27hp
Bill & Carole Smith
Freedom 35 Pedrick
SweeTART
Coyote Point
San Mateo, CA

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