New diesel. White smoke on start up

[Arizona_928]

I recently bought a kubota generator with a d722 engine in it. Since day one the engine has white smoke when cold. Clears up after around 5 minutes, or when loaded and warmed up. Is enough smoke to be worried as all my other diesels have never had this issue on such a brand new engine (current hours 45). I thought elevation might playe a role as I'm at around 7,000 ft...?


What do you guys think?

[oldE]

In my experience, white smoke upon start is almost always water. How does the oil look? Coolant?

Best
Les

[cabmandone]

Is this the new one you mentioned to me a while back? I'd start with the fuel filter and also verify fuel quality. You could have some water in your fuel. Might not hurt to drain the fuel tank, install a new filter, fill with fresh fuel and see if it clears up.

[asphaltgambler]

What was the ambient temp on those days?

[cabmandone]

Something else, is it really 5 minutes? What's the outdoor temp when you're starting it? It's clearing up because the engine warms and you get more complete combustion when the engine is warm. I've noticed on a lot of the new tier 4 engines that they tend to throw a lot of white smoke before they warm up. I still think I'd verify fuel quality and change the filter. Maybe drain the water separator and see how it acts. If it's cold enough that the glow plugs cycle, you could have a cold cylinder due to a bad glow plug too.

[Arizona_928]

Originally Posted by cabmando

Is this the new one you mentioned to me a while back? I'd start with the fuel filter and also verify fuel quality. You could have some water in your fuel. Might not hurt to drain the fuel tank, install a new filter, fill with fresh fuel and see if it clears up.

Yeah. I bought it at absolute genies.

Fuel is the same I use in my truck. I run a 100 gallon transfer and pick up diesel at Costco. I'll get a new fuel filter.

[Arizona_928]

Originally Posted by asphaltgambler

What was the ambient temp on those days?

Today mid 80's. Didn't require glow plug action. But when I use the glow plugs at 50ish it's the same white smoky

[Arizona_928]

Originally Posted by cabmando

Something else, is it really 5 minutes? What's the outdoor temp when you're starting it? It's clearing up because the engine warms and you get more complete combustion when the engine is warm. I've noticed on a lot of the new tier 4 engines that they tend to throw a lot of white smoke before they warm up. I still think I'd verify fuel quality and change the filter. Maybe drain the water separator and see how it acts. If it's cold enough that the glow plugs cycle, you could have a cold cylinder due to a bad glow plug too.

Around 5 minutes to completely clear without load. Today when I walked to the house and back it was still a little Smokey.

The glow plugs work and even when I cycle them an extra time when it's around 50. It'll do the same. Probably the tier 4 engine thing, or maybe bc it's idi?

[cabmandone]

It's doing this when it's warm out? I don't think that's normal. I haven't seen any of my new tier 4 machines do that when it's warm outside.

[wdfifteen]

Originally Posted by AZ_porschekid

Today mid 80's. Didn't require glow plug action. But when I use the glow plugs at 50ish it's the same white smoky

White smoke when it’s that warm? Something wrong. At 45 hours I’d talk to my dealer.

[Arizona_928]

Originally Posted by cabmando

It's doing this when it's warm out? I don't think that's normal. I haven't seen any of my new tier 4 machines do that when it's warm outside.

Yeah it'll smoke no matter the outside temp. Only when the engine is cold.
When it's fully warmed up and with load it'll run fine with no smoke.
It's not coolant as you smell the diesel and not sweet glycol. Coolant level is fine.


I was thinking the injection pump might be turned up too high from the factory, or possibly the elevation. The common rail truck I have seems to be fine, but the other injection pump machines seem to run more black smoke.

[Speedalac 930]

Check for air in fuel system or glow plugs not cycling.

[Arizona_928]

Originally Posted by Speedalac 930

Check for air in fuel system or glow plugs not cycling.

Hmm that's a good idea. I'm gonna go to town tomorrow and do a fuel filter. I'll bleed injectors while I'm in there.

[asphaltgambler]

At this temps it is not water vapor, especially at higher altitudes. It's incomplete combustion from over fueling. Is the pump totally mechanical?

[cabmandone]

Originally Posted by AZ_porschekid

Hmm that's a good idea. I'm gonna go to town tomorrow and do a fuel filter. I'll bleed injectors while I'm in there.

Might want to be careful with that injector bleeding. On these newer high fuel rail pressure engines they don't recommend cracking the injectors to bleed. I don't know what your rail pressure is on that engine.

[white85carrera]

I have a Kubota Diesel tractor and does the same. every time. since day one. dealer says "normal". white smoke for about 10 seconds. the beast is now 10 years old and strong like bull.

[cabmandone]

Originally Posted by white85carrera

I have a Kubota Diesel tractor and does the same. every time. since day one. dealer says "normal". white smoke for about 10 seconds. the beast is now 10 years old and strong like bull.

Maybe something unique to the smaller HP engines? I don't see that in any of the bigger machines I run with 50-74 hp when the temps are warm outside.

[Speedalac 930]

As mentioned be careful bleeding injectors. On a later common rail system don't do it. If it starts it will push the air out, that is a cause of white smoke. Cold is also a cause, later engine's cycle the glow plugs as the engine is warming up to eliminate the white smoke. A more serious cause is low compression. White smoke is unburned fuel.

[Arizona_928]

Originally Posted by asphaltgambler

At this temps it is not water vapor, especially at higher altitudes. It's incomplete combustion from over fueling. Is the pump totally mechanical?

Completely mechanical injection pump idi. No computers, nothing fancy. Just how I like them.

Talked to the 'local' kubota dealer. He said it's normal as long as it clears up.

[asphaltgambler]

It's likely the lower level of oxygen at that altitude that's essentially causing a 'rich' condition at start. Being that the pump is fully mechanical, someone very, very knowledgeable would have to turn the fuel delivery down a low speeds