3gm30 running warm and white smoke

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Ereiss
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3gm30 running warm and white smoke

Post by Ereiss »

After doing much $$$ work on the engine at Brewers I find that I am getting white smoke at 2k rpm and higher. The yard checked it today and said that temps went up at 3k rpm and the cooling water flow wasn't as great as they expected. The impeller has recently been replaced, the valves adjusted (in case that is impacting this) and the mixing elbow replaced.

They aren't sure what is happening but will be doing more research $$. Guessing could include 1) water pump needing replacing, 2) heat exchanger needing replacing, 3) some water piping needing replacing. $$$$.

Anyone have suggestions or experiences?

They are going to check the valve setting and check the pressure on the radiator cap to see if the head gasket is good.

Any suggestions would be appreciated.
Ed Reiss
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Mike Holibar
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Re: 3gm30 running warm and white smoke

Post by Mike Holibar »

Ed, from your description it sounds like the white smoke may in fact be steam, indicating a low raw water flow. White smoke from diesels usually occurs on cold starting and comprises unburnt fuel vapour. Hard starting diesels often pour out a good amount of white smoke before they fire and get started. Once running, blue smoke indicates oil burning and black indicates unburnt fuel/overloading. So I would check out the raw water circuit, starting with the intake valve (is it fully open) intake strainer, remove the heat exchanger end caps and have a look, just four nuts at each end, then have a look at the exhaust elbow connection. Any one of these things could be restricting the flow. Good luck,
Mike Holibar
S/V Fyne Spirit of Plymouth (Freedom 39PHS-1989)
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GeoffSchultz
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Re: 3gm30 running warm and white smoke

Post by GeoffSchultz »

I would agree with Mike. It's been cold enough around here that the white "smoke" could easily be steam. Typically real white smoke occurs when there isn't enough heat to burn the fuel and disappears when the engine gets hot. If you're running hot, that doesn't make sense.

According to a search that I just did:
If white smoke is still visible after the engine has warmed up, the engine may have one or more bad injectors, retarded injection timing or a worn injection pump. Low compression can also be a source of white smoke. Air in the fuel system can also cause white smoke.
-- Geoff
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Lola
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Re: 3gm30 running warm and white smoke

Post by Lola »

Hey, Welcome to the Repair of the Engine Club . Mine is a 2GM Yanmar, and I had all that done, and new Prop..$6000.00..Be sure to keep your Visa and Master Card handy...Are we having Fun Yet?..$85.00 per Hour....oh and Fair winds.

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Ereiss
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Re: 3gm30 running warm and white smoke

Post by Ereiss »

Thank you for the suggestions.

The white smoke does dissipate but is not related to temperature. It continues after the engine is warm and the day is warm. There is a heavy fuel smell (at least I think it is a fuel smell although I have no idea what a coolant cooking smell would be like) which is gagging.

Again, thank you
Ed Reiss
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GeoffSchultz
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Re: 3gm30 running warm and white smoke

Post by GeoffSchultz »

The white smoke does dissipate but is not related to temperature. It continues after the engine is warm and the day is warm. There is a heavy fuel smell (at least I think it is a fuel smell although I have no idea what a coolant cooking smell would be like) which is gagging.
That sounds like unburned fuel. When did you last have the injectors serviced?

-- Geoff
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Ereiss
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Re: 3gm30 running warm and white smoke

Post by Ereiss »

Could faulty injectors cause the engine to Ron warm at high rpms?
Ed Reiss
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GeoffSchultz
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Re: 3gm30 running warm and white smoke

Post by GeoffSchultz »

Ereiss wrote:Could faulty injectors cause the engine to Ron warm at high rpms?
I'm far from being a diesel mechanic, but I always pay close attention to problems in case I have them in the future. I have several questions:
  • Did the overheating start at the same time as the white smoke?
  • Could you have gotten bad fuel?
  • How is your oil level doing?
  • Does the white smoke smell like diesel, oily or sweet?
  • What happens when you run under sustained load?
  • How does the coolant look?
  • How hot is hot?
  • Do you have good water flow? (If not, have you tried Flomax? :lol: )
  • Do you see any oil on the water near the exhaust?
  • Any chance that you ever got water into a cylinder?
-- Geoff
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Ereiss
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Re: 3gm30 running warm and white smoke

Post by Ereiss »

Great questions, Geoff

* Did the overheating start at the same time as the white smoke? The overheating, I'm told by the yard, only occurs at high RPMs.
* Could you have gotten bad fuel? Possible, it went in last fall, put bug killer in it before the boat was laid up for the winter
* How is your oil level doing? Fine
* Does the white smoke smell like diesel, oily or sweet? It smells like a rich exhaust smell.
* What happens when you run under sustained load? Smoke comes out under load and without load. RPM driven
* How does the coolant look? Didn't look (I'm in Boston, boat is in Barrington)
* How hot is hot? Yard says heatgun shows 210 degrees
* Do you have good water flow? (If not, have you tried Flomax? :lol: ) They think flow is down and will try and clean out heat exchanger. I also asked them to check the newly installed impeller.
* Do you see any oil on the water near the exhaust? No sign of oil in the exhaust
* Any chance that you ever got water into a cylinder? Wouldn't know how to know that, or how water got in.

Yard will be doing the heat exchanger work and checking their valve adjustment work. It could be that the two issues are unrelated.

regards,
Ed Reiss
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THATBOATGUY
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Re: 3gm30 running warm and white smoke

Post by THATBOATGUY »

If it were me, I'd start by solving the water flow issue. You have to simply start at one end (the through hull) and work your way out the exhaust line. The heat exchanger on the 3gm30f is easily removed for cleaning and that is a highly suspect item for you at this point.

George
George and Kerri Huffman S/V Marquesa Freedom 40 CC CK Sail MarquesaImage

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