Yanmar 3GM30 white smoke (help)

[Wotname]

Originally Posted by robertmfranklin

......... The 3GM30F has too much compression to start with a hand cranch. And, I've never seen a decompression lever, but maybe I haven't looked closely enought.

The effort I needed to turn the pulley was almost beyond me. I needed a crank handle. Sounds like the OP should have one, as perhaps everyone should who owns a Diesel.

Is a crank handle available?

Should I make my own?

Maybe a properly sized socket and a long handled wrench?

Anyone know the specs for the nut on the crank shaft pulley?

Your 3GM30F does have decompression levers, three of them - one for each cylinder. They are located on the valve cover - see the red arrows.

A crank handle is available and it engages the camshaft. See the red circle. Yours might have a cover over it.

Normal hand start procedure is to operate all three decompression levers, set throttle as required, hand crank rapidly, release one decompression lever, if it fires release the other two levers (one at a time). Not always easy to keep turning the crank and releasing a lever.

[Rasselas36]

If you have diesel in your oil then it is probably the fuel pump.

[wildcat35]

It’s a stuck injector delivery to much fuel to one cylinder most likely change your fuel filters if you have not pull your supply lines off the injectors one at a time you should see a change in idle if so tighten move to the next one is one has no change in the idle that’s the stuck one remove rebuild or replace with new you can just but a nozzle much cheaper. Carry a spare and run some transmission fluid in you fuel from time to time though a couple quarts in the tank and it will clean your fuel system and keep your injectors happy.

[kaisardog]

no diesel engine should ever have a 'water/fuel' mix feeding from its RACOR water sep filter into its cylinders for combustion. the engine's increased temperature would cause an explosive pressure increase due to the vaporization of any h 2 0 'mixed with the fuel.' (water turns to steam. water in diesel fuel turns to steam. steam has much higher volume than liquid h 2 0. under Raoult's ideal gas law, Pressure x Volume =nRTemperature . the pressure increase inside the engine if water vaporizes is directly related to the temperature increase, since the volume of the engine is fixed.) . the same law pertains to why and how you can ruin your engine if seawater backs in thru the exhaust to a cylinder due to , for example, an improper exhaust system w/o a proper swan neck, etc.

[Shaneesprit]

Originally Posted by ShelleySailor

I have been reading a lot of forum posts and I think I may have hydrolocked my engine. before all of this happened I cranked my engine for quite a bit to get it started I did not know that I was suppose to close the water intake. I remember hearing a pop sound that did not sound healthy or normal and that is when I stopped trying. Later on a found a leaky fuel line and after replacing the fuel line and bleeding the air out of the line it started once again. BUT now now it starts with smoke, runs a bit rough for 5 minutes than I put it in gear and go and will run fine. The smoke goes away and runs smoothly.
although some sheen can be seen in the water so it may not be burning all the fuel?
Do you think this could be the result of hydrolock? or something else?

If you have been messing with the fuel lines and filters recently? Then this is where you should start, rule out all possibility of air getting into your fuel, especially from any work you have done recently.

If you have a bent rod then I would expect you to be able to hear that as a change in the diesel knock while running or a slight change in power, engine could run but normally I would expect that to be noticeable.

[Firefly44]

If there's any doubt about if there's water in the oil or fuel in the oil, I suggest sending an oil sample off for analysis. You get a great report back which gives you peace of mind and lets you know about any metal content in the oil too.

Dave in Charlotte Harbor

[skipperpete]

Originally Posted by kaisardog

no diesel engine should ever have a 'water/fuel' mix feeding from its RACOR water sep filter into its cylinders for combustion. the engine's increased temperature would cause an explosive pressure increase due to the vaporization of any h 2 0 'mixed with the fuel.' (water turns to steam. water in diesel fuel turns to steam. steam has much higher volume than liquid h 2 0. under Raoult's ideal gas law, Pressure x Volume =nRTemperature . the pressure increase inside the engine if water vaporizes is directly related to the temperature increase, since the volume of the engine is fixed.) . the same law pertains to why and how you can ruin your engine if seawater backs in thru the exhaust to a cylinder due to , for example, an improper exhaust system w/o a proper swan neck, etc.

Kaisardog you’re right about the water in the fuel. If it’s emulsified it can get through the primary and secondary filters, through the injector pump and finally to the injector tip where it indeed vaporizes and has the ability at that time to shatter the nozzle at the spray hole cavity. This damage was noticeable on engines with multiple fine spray hole injectors but not seen (by me) on precom engine injectors probably because those injectors (Pintle) have a really big single spray orifice and a very coarse spray into a precom chamber.
On the fine tip injectors ( atomizers ) once the tip is gone the injection is then a droplet of fuel that in a direct injection engine burns badly or not at all and shows as white smoke.
Not sure if I’m with you on the wet exhaust theory though[emoji848]

[kaisardog]

on the possibility of water entering thru a badly-designed exhaust: i've only read of boats getting water into the engine when thee's no swans neck and no water lift muffler . the theory is that when a following sea forces h 2 0 thru the exhaust hose opening on the transom, and there no swans neck and no waterlift muffler, then water from the following sea is forced into into the exhaust el and thence into the engine. this supposedly happens when poor design of the exhaust hoses omits a swans neck' loop and waterlift muffler and the exhaust opening on the transom is at a height roughly equal to the elhaust elbow.

[skipperpete]

Originally Posted by kaisardog

on the possibility of water entering thru a badly-designed exhaust: i've only read of boats getting water into the engine when thee's no swans neck and no water lift muffler . the theory is that when a following sea forces h 2 0 thru the exhaust hose opening on the transom, and there no swans neck and no waterlift muffler, then water from the following sea is forced into into the exhaust el and thence into the engine. this supposedly happens when poor design of the exhaust hoses omits a swans neck' loop and waterlift muffler and the exhaust opening on the transom is at a height roughly equal to the elhaust elbow.

I would suggest that the major cause of engine exhaust flooding is by water siphon, either by poor design or by a failed siphon break.....over cranking is a not too distant second and to a much lesser extent, problems with the mixer elbow ( insidious rather than catastrophic)
and the least common cause is transom entry.... it definitely happens but not as often as the other causes.

[Compass790]

Originally Posted by kaisardog

on the possibility of water entering thru a badly-designed exhaust: i've only read of boats getting water into the engine when thee's no swans neck and no water lift muffler . the theory is that when a following sea forces h 2 0 thru the exhaust hose opening on the transom, and there no swans neck and no waterlift muffler, then water from the following sea is forced into into the exhaust el and thence into the engine. this supposedly happens when poor design of the exhaust hoses omits a swans neck' loop and waterlift muffler and the exhaust opening on the transom is at a height roughly equal to the elhaust elbow.

We have a "swans neck" & a waterlift muffler but still have a valve on the exhaust at the transom to be closed in a storm in theory. I must confess to never having used it or tried to. Think it's a fine idea but I'd be amazed if the valve works due to buildup & corrosion.
Agree with all skipperpetes thoughts as to relative likelyhood of water getting into engine from exhaust & manifold failure added.
The most common cause of engine failure on the little Yanmars that I supply parts for is exhaust elbow failure. They are very expensive from Yanmar in NZ so owners tend to let them go till they fail.

[ShelleySailor]

I haven't checked in a while but these are all GREAT suggestions THANK YOU!!!. I still have this problem. The good news is that the engine runs just fine after the first 5-10 minutes. I have motored for 10 hours non stop a couple of times and the engine ran fine. I did have a fuel leak in the engine fuel filter coming from the bleed screw on top. I replaced it and solved the problem but still get white smoke for the first 5-10 mins. I thought it was an interesting hypothesis that air is getting in the fuel because I have been having fuel leak issues and had to bleed the fuel system 3 times but if still has air would it still start and run?
I have not done anything about it because I have called every diesel mechanic in the Boston area and everyone is booked and not taking any calls.
I think I will next check the anti-syphon valve. Opening the engine block is a bit above my pay grade. Oh and the oil is clean I have not seen any change in color since the last oil change or seen increase in volume.

[Dave9111]

Originally Posted by ShelleySailor

I haven't checked in a while but these are all GREAT suggestions THANK YOU!!!. I still have this problem. The good news is that the engine runs just fine after the first 5-10 minutes. I have motored for 10 hours non stop a couple of times and the engine ran fine. I did have a fuel leak in the engine fuel filter coming from the bleed screw on top. I replaced it and solved the problem but still get white smoke for the first 5-10 mins. I thought it was an interesting hypothesis that air is getting in the fuel because I have been having fuel leak issues and had to bleed the fuel system 3 times but if still has air would it still start and run?
I have not done anything about it because I have called every diesel mechanic in the Boston area and everyone is booked and not taking any calls.
I think I will next check the anti-syphon valve. Opening the engine block is a bit above my pay grade. Oh and the oil is clean I have not seen any change in color since the last oil change or seen increase in volume.

I have a number of diesels and the only time I have truly had white smoke (hold a piece of white paper next to the exhaust) was when water was being injected into the intake manifold from a bad EGR cooler on a Ford Diesel. It was truly white smoke and LOTS of it. (like I hope that no one calls the fire department)

If you are getting white smoke in low volumes, and you have put 20+ hours on the engine without issues, I doubt that you have a water intrusion issue. Its likely one of the other issues in this article.


https://www.capitalremanexchange.com...moke-by-color/

[Compass790]

Originally Posted by ShelleySailor

I haven't checked in a while but these are all GREAT suggestions THANK YOU!!!. I still have this problem. The good news is that the engine runs just fine after the first 5-10 minutes. I have motored for 10 hours non stop a couple of times and the engine ran fine. I did have a fuel leak in the engine fuel filter coming from the bleed screw on top. I replaced it and solved the problem but still get white smoke for the first 5-10 mins. I thought it was an interesting hypothesis that air is getting in the fuel because I have been having fuel leak issues and had to bleed the fuel system 3 times but if still has air would it still start and run?
I have not done anything about it because I have called every diesel mechanic in the Boston area and everyone is booked and not taking any calls.
I think I will next check the anti-syphon valve. Opening the engine block is a bit above my pay grade. Oh and the oil is clean I have not seen any change in color since the last oil change or seen increase in volume.

AFAIK air does not cause white smoke. Never heard that one before.

[ShelleySailor]

Originally Posted by Dave9111

I have a number of diesels and the only time I have truly had white smoke (hold a piece of white paper next to the exhaust) was when water was being injected into the intake manifold from a bad EGR cooler on a Ford Diesel. It was truly white smoke and LOTS of it. (like I hope that no one calls the fire department)

If you are getting white smoke in low volumes, and you have put 20+ hours on the engine without issues, I doubt that you have a water intrusion issue. Its likely one of the other issues in this article.


https://www.capitalremanexchange.com...moke-by-color/

I just read that article, thanks. I wonder if the smoke is related to fuel lift pump? it a bit leaky and I wonder if I should replace it.

[Compass790]

Originally Posted by ShelleySailor

I just read that article, thanks. I wonder if the smoke is related to fuel lift pump? it a bit leaky and I wonder if I should replace it.

Extremely unlikely your lift pump has anything to do with white smoke problem but yes replace it if it is leaking. There are cheap ones on Ebay.

Dunno how you can stand diesel leaks, they drive me more crazy. The mess in the boat is bad enough but the sight of it on the sea surface when the bilge pump goes of is disturbing to me anyway.