White smoke on engine startup...

[eweb101]

Hi All,


My Volvo Penta MD2040 is usually really easy to start. The last two times I’ve started it, it’s been difficult to get the engine to fire. Today it took a couple minutes of off and on cranking before it fired up. As I’m cranking, it puts out a lot of white smoke (could be steam) from the exhaust. As soon as it starts, the smoke stops. I ran the engine for 10 hours up the Chesapeake the first time this happened and after it started I saw no more smoke and the engine ran fine.


I thought maybe water in the fuel but I saw a thread somewhere that said there’s no way water could get past the injectors and make it to the exhaust so I don’t know if I should pursue a water-in-fuel problem.


Any ideas on where I should start looking?

[DougR]

Are you using the glow plugs when starting? If so, are they working properly?

Check to see that you are getting 12v at the glow plug power strip. Perhaps the glow plug relay has gone.....

Or perhaps the relay is OK but you have lost a couple of glow plugs.

DougR

[a64pilot]

The white smoke is almost certainly fuel vapor, that is why it disappears very quickly once it starts.
So your getting fuel, so the next question is as has already been asked, do you have glow plugs, and if so, then they probably don’t work.

To further isolate this, if it’s glow plugs, then it will start fine once the engine is hot, no smoke and quick starts.

[atoll]

Originally Posted by eweb101

Hi All,


My Volvo Penta MD2040 is usually really easy to start. The last two times I’ve started it, it’s been difficult to get the engine to fire. Today it took a couple minutes of off and on cranking before it fired up. As I’m cranking, it puts out a lot of white smoke (could be steam) from the exhaust. As soon as it starts, the smoke stops. I ran the engine for 10 hours up the Chesapeake the first time this happened and after it started I saw no more smoke and the engine ran fine.


I thought maybe water in the fuel but I saw a thread somewhere that said there’s no way water could get past the injectors and make it to the exhaust so I don’t know if I should pursue a water-in-fuel problem.


Any ideas on where I should start looking?

drain the fuel separation bowl on the fuel filter,it may be full of water

[eweb101]

dougr and a64pilot that's a good idea to check the glowplugs. Easy enough to check that the relay is working but I'll have to figure out how to check individual glowplugs.



atoll I have been seeing a little bit of water in the primary fuel filter, I just didn't think it would cause the symptoms I'm seeing. I will empty the filter though since it's not hard to do.

[a64pilot]

You check glow plugs by checking resistance, there is usually a strip of copper connecting them, disconnect that and check plugs individually, bad ones will be an open circuit, or should be anyway.
Of course seeing if the system is working is as simple as checking for voltage

[Ida_Lewis]

It means a new pope has been elected.

[Jannie Radiance]

Do you you run your engine at anchoer for battery charging? No load onthe engine?

[Stu Jackson]

It's normal. Listen to a64. You should be more concerned about why it doesn't start right away. That is a safety issue.

[Symphony]

Originally Posted by Ida_Lewis

It means a new pope has been elected.

Best post of the day Award!

[a64pilot]

Water can destroy a Diesel fuel injector.
They way it will destroy one is by blowing the tip off, the way it does that is when water hits the superheated fuel injector it turns to very high pressure steam, and there goes your injector tip.
It’s not a 100% thing of course, but it can occur, remember the injector tip is inside of the combustion chamber if your wondering how hot it gets.

[boeing1]

one other thought, how fast does your starter spin your engine

[sheldon957]

It could be one or more injectors going bad. Try a good diesel cleaner first to try and clean the tips. In my mechanic shop I owned, that worked about 50% of the time. The BG system worked well.

https://costeffective.com.au/2017/03...s-you-a-story/

[Lepke]

As engines age, the compression pressures decrease, especially when cold starting. The rings and cylinders have worn and the rings contract a small amount when sitting. The pressure after starting and ring design, force the rings tightly to the cylinder wall. And everything becomes normal.

Heat, especially a block heater work best for starting in the cold. If the glow plugs no longer provide quick starts, and new ones don't make a difference, larger ones can sometimes be fitted.
My mains, early Detroit Diesels, had 20,000+ hours. I bought the boat planning on overhauling the engines. Running the block heaters a couple hours and they started up fine. After the overhaul mileage increased about 1.5 kmpg.

[erie]

Originally Posted by a64pilot

The white smoke is almost certainly fuel vapor, that is why it disappears very quickly once it starts.
So your getting fuel, so the next question is as has already been asked, do you have glow plugs, and if so, then they probably don’t work.

To further isolate this, if it’s glow plugs, then it will start fine once the engine is hot, no smoke and quick starts.

Typically the white smoke you see coming from the exhaust is just water vapor. As it heats up, the white smoke will go away...black smoke is unburnt fuel....