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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Texasjack on July 08, 2013, 09:48:20 AM

Title: kubota white smoke problem
Post by: Texasjack on July 08, 2013, 09:48:20 AM
I was hoping someone on here could help me figure out the white smoking problem on my Kubota 4 cylinder ( V2203B6) genset. I use it on my Eagle bus, it only has 85 hours and bought it new. Changed fuel filter, ran clean fuel through it for 2 hours with injector cleaner added. Starts up clean, then starts smoking. Enough to be a scene. It has been sitting for the last 4 years. Oil is clean. ??? thanks for any help
Title: Re: kubota white smoke problem
Post by: white-eagle on July 08, 2013, 10:02:47 AM
i'd say take it back where you got it.  with that few hours, it's got to be warranty fixable, and you might screw that up if you mess with it too much.
Title: Re: kubota white smoke problem
Post by: Texasjack on July 08, 2013, 10:05:56 AM
Bought it 4 years ago, Has worked fine until 2 weeks ago..
Title: Re: kubota white smoke problem
Post by: wg4t50 on July 08, 2013, 10:34:44 AM
I would start off using a new fresh can of diesel fuel, run on that and add as much load as you can, see if it clears up in a half hour.  I have seen bad diesel fuel act the same way, one case it would not run on the diesel fuel provided by the fuel company, ran perfect on my standard diesel fuel I brought with me on the service call, ran fine on my fuel, reconnect to the new fuel, it started acting uo within 2 miutes, switch back to my fuel, all cleared up.
Guess why I trust few diesel fuel brokers.
Good luck
Dave M
Title: Re: kubota white smoke problem
Post by: bobofthenorth on July 08, 2013, 11:00:39 AM
Does the rad pressure up immediately when you start the engine?  Is it using coolant?  When it starts clean & then smokes that sounds like coolant to me.  Especially so if it came on all of a sudden.
Title: Re: kubota white smoke problem
Post by: Texasjack on July 08, 2013, 11:34:32 AM
Pressure up immediately? I assume so.. Distilled water and coolent. You mean like a head gasket?
Title: Re: kubota white smoke problem
Post by: bobofthenorth on July 08, 2013, 12:15:02 PM
Assuming won't help with troubleshooting.   A cold engine should not have pressure in these rad.  Don't assume - check it.  Mike Lutestanski says "you get what you inspect, not what you expect". And the point of the coolant question was whether coolant is disappearing from the rad.
Title: Re: kubota white smoke problem
Post by: Texasjack on July 08, 2013, 12:27:09 PM
So there should be no pressure on the cooling system when cool? ok, just didnt understand the question. Ran her yesterday, will check. Seems crazy a water leak into the combustion. I hope not...
Title: Re: kubota white smoke problem
Post by: johnjem on July 08, 2013, 04:06:23 PM
I have run into that same problem,make sure the magnetic actuator fuel shut off is in the wide open postion not half way,If it is only half way open then I would clean and adjust ,I hope I helped.john 
Title: Re: kubota white smoke problem
Post by: Geoff on July 08, 2013, 05:47:11 PM
Remove the exhaust manifold and see which clyinder is the problem.  I dought it is all of them.  Then you have to remove the head and see what the problem is.  White smoke on a diesel engine with high compression means something broke and the white smoke is unburned diesel, not coolant.

Of course, you have to know what you are working on.  Otherwise, take your chances on a dealer.

I do this almost everyday.  That is, troubleshoot, not take my chances on a youngster woking at an RV repair shop.

--Geoff



Title: Re: kubota white smoke problem
Post by: Texasjack on July 09, 2013, 04:53:11 AM
Couldnt it just be a bad injector?
Title: Re: kubota white smoke problem
Post by: eagle19952 on July 09, 2013, 06:03:54 AM
Quote from: Texasjack on July 09, 2013, 04:53:11 AM
Couldnt it just be a bad injector?

Not likely,  crack an inj. line at the pump, (engine running), one at a time, if each crack makes it sound/run worse...the cylinder/injector are GOOD,  no change then you have found the bad hole....
my guess is a cracked head.
Title: Re: kubota white smoke problem
Post by: luvrbus on July 09, 2013, 06:21:52 AM
One should unload the generator and run it a few minutes before shutdown to prevent head cracks as good as the Kubota is they will crack heads and that can be prevented 
Title: Re: kubota white smoke problem
Post by: Oonrahnjay on July 09, 2013, 06:43:52 AM
Quote from: luvrbus on July 09, 2013, 06:21:52 AMOne should unload the generator and run it a few minutes before shutdown to prevent head cracks as good as the Kubota is they will crack heads and that can be prevented  

     I do that with my VW TDI and my bus engine if I've pulled directly off the highway but I never thought to do that with my generator.  Thanks for that info, Clifford.  Is just a smooth idle for a few minutes the right thing?    Thanks.
Title: Re: kubota white smoke problem
Post by: opus on July 09, 2013, 09:02:53 AM
What does the smoke smell like?  Raw fuel, coolant?
Title: Re: kubota white smoke problem
Post by: Texasjack on July 10, 2013, 10:25:13 AM
It drools drops out of the exhaust, like rusty water... oil still looks good and runs fine...
Title: Re: kubota white smoke problem
Post by: wg4t50 on July 10, 2013, 10:31:19 AM
Still sounds like crappy diesel fuel, still suggest running from a jug of good fresh fuel, see if it cleans up.
BTDT
Dave M
Title: Re: kubota white smoke problem
Post by: junkman42 on July 10, 2013, 02:05:08 PM
Bad head gasket/head/precombustion chamber?  My educated guess.  John L
Title: Re: kubota white smoke problem
Post by: Texasjack on July 12, 2013, 12:30:26 PM
Ive been running her on a 5 gallon tank with some injector cleaner..Ran it maybe an hours worth.Still smoking. Oil clean. Everyone thinks its a head gasket or cracked head. With only 85 hours of total run time? Wow, that would make it the most expensive POS I have ever bought! lol
Title: Re: kubota white smoke problem
Post by: OneLapper on July 12, 2013, 01:35:04 PM
This may have been suggested, but try running it under max load with fresh fuel for several hours.  Partial load doesn't help.  Clean or replace the air filter even if you think it doesn't need it.  

Use a IR pyrometer to check the temps of the exhaust ports.  They should be very close, the one closest to the water pump is usually the coolest.   If one cylinder is cooler than the rest, there's an issue with that cylinder.  

As suggested, while the genset is running under load, crack an injector line, one cylinder at a time.  Watch for several minutes (yes, messy) and observe if smoke diminishes.  If so you have a leaky injector or low compression on the cylinder.  

You can check compression with a tester easily.  You can swap injectors to see if the temp difference moves.  

With any luck it's just a mouse nest in the air filter.  

How many years did it sit without running?
Title: Re: kubota white smoke problem
Post by: opus on July 12, 2013, 01:46:04 PM
Air filter would be black smoke.  How about a stuck injector is what I am thinking.
Title: Re: kubota white smoke problem
Post by: OneLapper on July 12, 2013, 02:02:02 PM
Quote from: opus on July 12, 2013, 01:46:04 PM
Air filter would be black smoke.  How about a stuck injector is what I am thinking.

Yes, if its completely clogged it can produce black or grey smoke.  If this engine only has a slight haze in the exhaust it'll be difficult to determine whats the cause.   Could be a partially dirty air filter, leaky injector or low compression.  
Title: Re: kubota white smoke problem
Post by: c-coop on July 12, 2013, 04:20:24 PM
I have seen this many times in our small marine gen sets Isuzu and Yanmar engines excess water or fuel on top of the piston when you go to start it puts a slight bend in the connecting rod which dosen't let the piston come completely to the top which causes lost compression and unburned fuel [white smoke]
Title: Re: kubota white smoke problem
Post by: Geoff on July 12, 2013, 05:43:38 PM
Try
Title: Re: kubota white smoke problem
Post by: Texasjack on July 18, 2013, 03:25:36 PM
Its has been run at least 2 times a year over the last 4 years.
Ill change air cleaner and check temps on cylinders, also other suggestions.
Iwo
uld like to exhaust my options before tearing her apart. Did i mention 4cylinder 20kw?