I just got a 100 kw Gen, Running a Deere 6068T engine. It smokes like no other. It looks white but it doesn't smell like unburned fuel. I found couple leaking fuel connections i fixed those. Any suggestions would be great other than taking it in for service.
Do you have any way to put a heavy load on the genny? Possible it's been sitting for a long period or ran with light loads? It should clean up after loaded for a while, if this is the case. Is the engine oil overfull or diluted?? Does it have much blowby? Have you changed fuel filters? If it had fuel in it when you bought it who knows what could be in there?
How many hours on it and how much blowby. Could be passing some oil from the turbo, give your inlet pipe an inspection sometime.
it has apx 17k hours. No clue on blow by.. I have a friend coming to look at it Friday.. Oil was changed 2 months ago.. It's still thick no trace of fuel. I used it today to power my concession trailer about 100 amps at max. It didn't' smoke as much, as no load. As in the fuel no clue how long that's been in it.. This was used as a rental and it was smoking when they had it and did very little diag. They think it's just injectors.
That photo looks like the classic case of a genset having been run for long periods at very low or no load. Before laying a wrench on it get it connected to a resistor load bank that can take at least 50% of the genset output and preferably somewhere around 80/90%. Run it for a couple of hours at as much load as it will stand and then check the smoke from the exhaust again. You may find that's all it needs, and even if not piston rings/liner condition is likely to be the root cause of the smoke, not injectors.
ok, Im taking it to my paintball field today.. Going to run my compressor.. IT was loaded tested april last year and same result happened
Thanks for telling us that after you asked for opinions ........ nothing like getting the full story in bits & bobs. Is there anything else we should know..?
I just got that email in the day i posted it. .When i got it i was told nothing other than it smoked little.
ok thanks.. I will try that i used it this weekend. But max amps i was pulling is 83 amps and of course It wouldn't smoke under a load. But when my fryer kicked off it went back to smoking.. I ran my scuba compressor on it. 3 phase 40 amps, It ran great no smoke.. Until it was done filling up.. BUt that was the first time i ever ran the Elec side of that compressor and was much much faster than the Diesel side.
To test for a bad injector have you tried cutting out the injectors one at a time and running the engine at no load to see if the smoke clears..? I know it will run like a bag of bolts with one cylinder off but all you are trying to achieve is to see if the smoke clears, not run it for an extended period.
I had all 6 injectors replaced. And it's still blowing smoke. I'll have it back home on Monday. And going to do a compression test on it. I know I said it smokes at idle. But it really doesn't idle it runs st 1800 rpms no load or loaded.
Would it be pretty easy to pull off the intake and exhaust manifold and look for oil pushing past the valve guides? I'd imagine valve guide leaks would reduce quickly under boost/load Nige's suggestion is a good one, our genset had a variable exciter and the mfg said, once a year, short the bus bar, excite to 0 and warm the engine up, increase excite until 90% amperage is reached, run for 1 hour It was an old old generator but doing that seemed to make it start a lot easier.
Sometimes if a genset has been run for long enough on a low or no load the piston rings end up being baked into the grooves with carbon and nothing but a stripdown and clean along with new piston rings will fix them.
So if the rings were stuck, would an oil sample show high fuel? or would it just show up as high oil consumption?
On a Cat engine it would most likely show up as high soot due to the blow by, because the engine isn't burning any more fuel than normal. On this particular engine I honestly don't know.
I think you need to run it under full load for a extended time frame. A few minutes under load will not clean it up. All hospital generators in the USA which are typically run for 30 minutes once a week are now required to run a 4 hour load bank session every three years. History has shown many times that when needed they were not performing due to crapped up from running with out enough load. I've seen your issue dozens of times. But then again you do have 17,000 hours so who knows.
That also shows up deficiencies due to age. As told to me by the CAT tech: Had a hospital in Portland with some three or four year old CAT gens, power went out in a storm, so both generators auto start, sync and transfer the load. Both engines running normally, all green, so #2 shuts down and waits faithfully. #1 carries the load handily for fifteen or twenty minutes, senses an overheat. Number 2 fires back up, syncs, takes over the load and #1 shuts down. You can see this coming right? Short time later #2 overheats and there's nobody left to turn to. Now we're down to battery lights and OR's where they're bagging patients by hand to keep them breathing. Not happy. The external coolant heaters were plumbed in with some nice coolant hose that rotted but looked okay, and of course both were installed at the same time with the same hose. Extended runs under load show up some of these unexpected issues.
Ok. just a update.. It's at John Deere, There is ALOT of carbon build up on the exhaust ports. Had the head pulled off the cylinders look great you can still see the marks, There is some carbon build up on the piston tops and at the top of the cylinder, Im sending the head out to be checked. There also was no thermostat in it. Would also explain the carbon build up Since the engine isn't building any heat.
well that sounds horrible! no thermostat, poor beast.
The carbon IMHO is a classic symptom of running for long periods with no/low load, the lack of adequate coolant temperature due to the missing thermostat has just added to the problem.
I've been thinking about the missing thermostat and wondering if there was some sort of cooling system over-temperature issue that caused it to be removed in the first place..? Do you know anything about the history of the set before it came into your hands..? It may be a good idea to go over the cooling system with a fine-tooth comb looking for problems while the engine is disassembled. Another thought - I hope they are planning to pull the pistons and replace the rings, because I'd guess that the piston ring grooves are going to be full of carbon as well.
Ok guys going to wake this back up. the generator has been sitting at john deere getting worked on. $3600 later. it smokes on startup until it gets warm. well that was the case. im at a event now and its still smoking not as bad. The work they di. rebuild the head. found alot of carbon build up in head and on pistons. cylinders looked great can still see the marks. has excellent compression. Other than a injection pump thats cost 1200$ and other ideas
I'd have to suggest jump up one to the post from Nige.
Did they replace the piston rings..? If not then simply on the basis of the carbon buildup on the tops of the pistons they should be taken out the back and shot without the benefit of a last cigarette or a blindfold IMO. Other than that has it been on a load bank and loaded up to 70-80% of rated output for an extended period..?
load test yes. Was a 2hr load test.. And they noticed it didn't smoke under a load.. That's when they suggested injectors which i did that and same problem.. John deere felt the rings were good since the compression was within specs. on every cylinder and all were just about the same.. And they could still see the hone marks. They also found it didn't have a Thermostat. When running in my yard under no load it will smoke until it gets up to 170 than stop.. And once in while will smoke again for min and stop.. And that's basically what it did today.
I'd have wanted it run under a good load for 24 hours at least, not 2. It's not a "load test" to look at the performance it's putting enough load on the engine to make it bark a bit over an extended period and get it hot enough burn off all the carbon that might be left. I don't care what they say about the compression being within spec, for the amount of carbon that you say they found on the tops of the pistons IMO they were criminally negligent in not replacing the piston rings. The extra cost in parts and labour would have been minimal bearing in mind how far they'd gone into the engine already. I've seen hone marks still visible on engines that were pulled for overhaul at 20,000 hours so don't take that as any indication. My feeling is that the rings are glazed and no matter how long that engine runs with them in it's going to smoke to a greater or lesser extent. How much it smokes will be enitrely dependent on the load that's put on it.
I will talk to them monday again.. This unit has 20,000 hours on it.. What pissed me off when i picked it up. It was still smoking and i just paid them 3600$ Im at the point do i need it or sell it. I really don't need it now. It was to be used at my paintball field to run my lights and compressor. But since i am moving, back north i kinda don't need it. But im not sure is it worth what i have into it..
So today i went out and played with the injection pump.. I noticed it wasn't sitting on the line that's marked on the block.. it was below it.. If i move anymore below it just gets whiter smoke. If i advance above the line. It clears up.. I have it all the way as i can above the line and the smoke is almost not visible.
Which injection pump does it have? The white smoke appeared to me to be retarded timing. Was it like this when you got it ? If the injection pump was replaced, if the engine was bared in the opposite direction of rotation to find top center the gear lash would not have been accounted for thus making it out of time. Pictures of the injection pump would help to determine correct timing procedure.
The Pump is a DB4.
Looking at the load test you posted earlier it loos like they only ran it at over 90% for a bit over an hour. No where near long enough if this thing has run at a light load long enough to carbon things up. Did the dealer not check the pump timing when they were rifling though you pockets for spare change? To me that engine smokes worse than an old tired Detroit with broken rings! I I always like the old 71's and 53's!
Put the pump on the mark on front cover, Time engine to tdc 1 . The timing hole is located on the same side of the engine as the injection pump. I use a Phillips screw driver to find the hole in the flywheel. Remove the small timing plate on the side of injection pump, you will see a small mark stationary mark in there, rotate the engine in normal rotation until the timing hole in flywheel is located. At this point the engine is either TDC 1 or TDC 6. If you are on TDC 1 you should be able to now see the other timing mark on the rotating part on the injection pump, it should be dead in line with the stationary mark, if it is not it is out of time. After the finding the timing hole in flywheel the mark on the rotating assembly in the pump is not visible you are on 6, Rotate it 360 and look for the marks in injection window for line up.
I have a 6068T in my Aljon baler that did the same thing. John Deere came and hooked it to their computer and declared the injector pump was on its way out. New pump and the problem was solved. Not saying that this is your problem just my engine did the same thing