L4240 White Smoke and Stumbling Idle on Cold Start

[Ken45101]

My M5040 acts like that. The other equipment doesn't. (Well the 12 year old Kubotas put out black smoke for a bit.) This has been going on ever since I got the 5040. I suspect it's the design/timing and nothing to worry about.

 

[PhilY]

White smoke means water.
Black smoke means too much fuel.
Smoke with a Blue tinge is engine oil.

 

[PhilY]

My M5040 acts like that. The other equipment doesn't. (Well the 12 year old Kubotas put out black smoke for a bit.) This has been going on ever since I got the 5040. I suspect it's the design/timing and nothing to worry about.

The engine cranks a couple of times before it fires up. While this is going on, fuel is being delivered, and therefore has too much fuel once it comes to life. This and the fact that the cylinders aren't warmed up and able to consume all the fuel would be why I would think there's black smoke on start up.

 

[avc8130]

White smoke means water.
Black smoke means too much fuel.
Smoke with a Blue tinge is engine oil.

That is true in gas engines.

White some in a diesel at startup is indicative of cold cylinders generally.

ac

 

[PhilY]

That is true in gas engines.

White some in a diesel at startup is indicative of cold cylinders generally.

ac

Learned something new...thanks! I looked it up and it appears to happen when diesel comes through the exhaust intact and unburned. The exhaust will also have a slight diesel smell. Here's a link I found on smoke coloration and the story it can tell.

Diesel Smoke tells YOU a Story…

Edit: However, I bet the increased diesel smell will be all that much more notable over the normal smell of exhaust.

 

[jpaeye]

My 2012 L5740 does the same thing. Above about 50-55 it starts right up with minimal smoke. Below about 45-50 it fires, but spots and sputters for 10-15 seconds until it smooths over, blowing white smoke all the while. I believe your situation is normal. I have read that this behavior is due to the retarded ignition timing which is retarded to better meet emission standards.

 

[allen in texas]

My 2010 L5740 does it too. Has since it was new. I spoke to the dealer about it and he said they all do it. On really cold days 20 and below, I cycle the glow plugs 2 or 3 times. Seems to help a lot.
My dad forgets to do the glow plugs, just fires it up. Sounds like the pistons and crankshaft are going to be on the ground in a few seconds but she finally cleans up and runs. The only sputtering after that is the argument going on between me and my dad (82) about him not using the glow plugs. "boy we never had glow plugs back in '43 we just dosed 'em up with a can of ether".
"Dad, this ain't 1943, use the frickin' frackin' glow plugs!" lol
My 05 L3240 did NOT do this.

 

[Member]

Thanks very much to everyone who replied.

It looks like my local Farm and Fleet carries Power Service. I'll try some of that and see what happens.

Thanks!

--
Dan