Hello All, First I will apoligize. my problem is not with my excavator. It is my red-d-arc diesel welder. But I didn't see any where else to post here that was more appropriate. I also figured lots of diesel experience here. The engine is a 4 cylinder Kubota. V-2003 non turbo. The engine is a 2009. Was working fine then go to start it the other morning and it spewed a white/grey smoke for about a minute before it cleared up. Does it each time I start it now. Other things to note: - it does fire right up no cranking necessary. - spews heavy white/grey smoke for a minute or so and runs rough. Then seems to run fine with a little blue smoke here and there.] - Coolant is up . The welder is stuck on an island job so I cant just take it to a shop to look at. Has any one got any ideas what this might be? I was thinking a bad injector..... My other question is will I be doing damage to the engine by starting it if fuel was leaking in? Please let me know your thoughts. THank you and again I am sorry for posting in this area if it was not correct too.
I don't think it's leaking fuel in while the engine is off, so much as one injector dribbling while it's running. Do you have individual injector lines on that engine? loosen them one at a time and see if the smoke goes away, that's the bad injector. It could damage the piston so if you find a bad injector, then it's worth replacing it sooner rather than later.
I'm thinking hosing injector as well, not uncommon with pintle type injectors. This can be quite damaging over a period. If this is the problem, it will only get worse.
Ok thank you guys. is a hosing and dribbling injector the same thing? If this is the case is it bleeding the pressure off after I shut it down and all that fuel in the cylinder is the white smoke and rough running? The questions I guess is can I run like this for another day or is this the type of damage that happens quickly. The Kubota dealer said not to worry about it it wont damage anything but I always like to ask lots of questions. Yes this has individual lines to each injector and then return into fuel tank. ITs running well once it warms up a bit with just a little blue smoke here and there....
Sounds like injectors dribbling/hosing.. BUT.. I would check the glow plugs first.. a burnt GP will give the same results..cuz the cylinder isn't hot enough to burn the fuel.. white smoke and slight miss.. Just unscrew the GP and hook 12v + to the top spade and - ground to the body.. it should glow red hot in seconds.. DONT TOUCH THE TIP!!.. ITS RED FOR A REASON!!!
I'd run it another day or week as long as it's not making any different noises, and you're not beating it. If it's the glowplug it won't hurt anything ever. You can check the glowplugs with an ohmmeter while they're in the head. Easiest to disconnect the electric wire at each one, but if the engine has an ammeter and and remember the "drop" changing by 1/4 at the same time the smoking started, then there's the tip off. My understanding is very little fuel leaks out when the engine is off, it only takes a tiny amount to reduce the pressure in the line to zero. The injector is leaking a bit of fuel off while running and that is what makes the white smoke, maybe it's so bad at first that there's not enough pressure in that line/injector to fire off that cylinder?
Hi Delmer and pump guy Thank you for the comments. Would a bad glow plug cause a little smoke ( blue) while it was running? I thought the glow plugs only ran while I held the preheat button? The reason I worry about it is someone said if it is leaking the fuel will wash cylinders and cause bearing damage? Also if I shut if off for a break ( say 30 minutes) it will smoke again on start up....engine should still be pretty warm then . I am mostly worried about causing engine damage. I should be able to wrap up this job I n another day or so then barge back and put in shop to work on it. Can someone give me detailed instructions on how to check the glow plugs in the machine with an ammeter? Thanks very much.
Is there an ammeter on the machine? or do you have a multimeter? If you have a multimeter, use the ohm setting, and check each one separately. They'll be something like a fraction of 1 ohm. If you have a cheap meter you'll get 0,0,0 and a bad one will be infinity or in the thousands. A test light will work just as well, hook it to positive, it should light up when you touch ground. Then check each glow plug and see if it connects to ground or if it's burned out. edit again: a bad glow plug will not cause anything when hot, a leaking injector will cause blue smoke. Smoking on warm startup is not surprising with either a bad injector or glowplug. one more: a leaking injector can cause detonation, and bad problems. That's made worse by advanced timing, hot operating temps, high boost, high load. Think Jethro pulling with his cranked up Cummins. Not as likely to cause you any trouble on a Kubota for one more day, but listen for any pinging.
Ok. I have both a good ammeter and test light. I will try this. Thank you
An ammeter that will read more than an amp is less common than a regular multimeter or test light, so I ignored that. Hook up each one individually and find the one that's not drawing any amps. If you have a clamp meter it's even easier, leave them all hooked up and move the meter. sorry for all the edits, you got ahead of my thinking there.
Thank you again fellows. I have my fingers crossed to have another day with it and no engine damage. It seems to be running fine when the smoke clears.....makeby just a little rough..... if you listen close.
does it start and run smoothly when cranking while puffing constant smoke, or does it blow intermittent smoke Os and have a rhythmic miss? white smoke is unburned fuel getting to the exh, so dribbling injector is likely. i have an older kubota 2 cylinder that will puff white and have a dead hole for the first 5 mins, then gets up to temp and runs perfect when the lazy cylinder starts firing. zero smoke after that. ive gone through injectors a few times and assume is compression related.
its pretty constant white/grey/liitle bit of black. Runs rough for a minute or so then evens out....then just a little blue smoke.
Could you resolve the white smoke issue at startup? I have Kubota V2203 in a Bobcat S130 with similar symptoms - White smoke only with startup for a few minutes. I've replaced the glow plugs and had the injectors refurbished without any success.