Community Forums

Bumps · 02-20-2015, 07:50 PM

Wow! That's a quiet generator! Yea, there's definitely smoke, too. Bummer. \ken

TQ60 · 02-20-2015, 08:50 PM

Be certian to keep copies of everything!

Copy yourself on all emails sent.

Forward copies of all received to yourself.

Keeps copies in your sent box.

Register unit with Cummins and follow up with tech support to be sure it is in the system and confirm exactly what you need to do if anything or watch for.

PushedAround · 02-20-2015, 08:55 PM

How long was it running before you took the video? Was it cold, or had it been running for a while. Was there any load on it when you shot the video?

jondrew55 · 02-20-2015, 09:02 PM

Quote:

Originally Posted by PushedAround

How long was it running before you took the video? Was it cold, or had it been running for a while. Was there any load on it when you shot the video?

It had been running a while, maybe 20 - 30 min when I took the video and it was under heavy load (rear heat pump on, convection oven and elect water heater on). I ran it for at least 2 hours and it was doing the same thing

powerboatr · 02-20-2015, 09:21 PM

did you or they just do a sanity check on the airfilter.

mine will slight black smoke once in a blue moon when the load jumps

either way its a young genny, be polite and get em to fix it

Ray,IN · 02-20-2015, 10:00 PM

Keep a close eye on oil level, perhaps even mark it with a scribe after it's been off overnight, then monitor that level each morning. That much smoke has to have a source, and I doubt its because it's new.
What brand and weight oil is in the unit?

TQ60 · 02-21-2015, 12:58 AM

Some questions...

What is different from when cummins tested good and you tested smoky?

Ambient temprature (in shop compared to outside)
Any doors or access covers open?
Time of day?
Anything else?

If cold it may not run as well as warm.

Our real old bobcat hates to start in cold and smokes like a chimney until it warms up so it may be a weak injector or something relating to temperature maybe.

Being new should not be excuse as new not allowed to smoke anymore...gvt funny about that nowadays

D Lindy · 02-21-2015, 07:40 AM

Have you called back to Cummins South where you had it to inform them that it had started smoking again? I would and make sure that they noted and the service work papers that they had from the last visit that is had started smoking again. Do you have a power display so that you can see at what % of load or AMPS that it started smoking. It sounded like maybe there was not sufficient load on it at Cummins to cause it to smoke, because at home you added a 3rd load draw on the system. It could very well be that there is a crankcase breather issue that doesn't show up until under very heavy load, and if the rings are not fully seated you'll get blow-by and this could be causing the oil smoke.

PushedAround · 02-21-2015, 07:50 AM

Quote:

Originally Posted by D Lindy

It could very well be that there is a crankcase breather issue that doesn't show up until under very heavy load, and if the rings are not fully seated you'll get blow-by and this could be causing the oil smoke.

Typically, ring seating is an issue with the compression rings, not the oil control ring. Blow-by (of the compression rings) will pressurize the crankcase and create an oil filled vapor. If the generator has a system that vents this pressure into the intake to burn the vapors (think emissions) possibly this is the source of the blue smoke. A quick check of the intake down stream of this vent would reveal if this is the problem or not. If not, then crankcase oil is clearly getting past the oil control ring for some reason. Either way it is a big deal on a new engine.

jondrew55 · 02-21-2015, 08:35 AM

Quote:

Originally Posted by D Lindy

Have you called back to Cummins South where you had it to inform them that it had started smoking again? I would and make sure that they noted and the service work papers that they had from the last visit that is had started smoking again. Do you have a power display so that you can see at what % of load or AMPS that it started smoking. It sounded like maybe there was not sufficient load on it at Cummins to cause it to smoke, because at home you added a 3rd load draw on the system. It could very well be that there is a crankcase breather issue that doesn't show up until under very heavy load, and if the rings are not fully seated you'll get blow-by and this could be causing the oil smoke.

I sent the service guy an email with a link to the video. Before I had taken the coach to Cummins I had seen it smoke with the heat pump and oven running. I don't know how many amps it was drawing before it became visible.

I'm sure they'll take care of it. Its brand new, less than 2 months old. Its just one of those "Could not duplicate" things that come up all the time in any kind of diagnostics. I was there and there was no smoke under load so I can't blame them. I turned the generator on and put the loads on. Next time I'll run everything. My only concern is if they actually see the smoke and tell me its not a problem. Then I'll have an issue on my hands.

I know I'm not the only person out here with a diesel generator and I'm sure someone would have chimed in by now saying "oh yea, they all do that for the first 50 hours and then stop"

TQ60 · 02-21-2015, 09:02 AM

What you need to do now is figure out how to make it smoke so you can demonstrate it.

If it is worse at a time of day due to ambient temp then make sure that is when you test for shop.

How many electric heaters can you borrow?

That would be easy was to place a controlled high load...okay witg 4 but smokes with 5...

stuhly · 02-21-2015, 09:20 AM

Try loading it and let it work for eight hours straight.

PushedAround · 02-21-2015, 10:04 AM

Quote:

Originally Posted by stuhly

Try loading it and let it work for eight hours straight.

Not a bad idea at all. For whatever reason it is smoking, you probably can't make it worse by running it, and may a long session under load will seat everything, if that is what is causing the problem to begin with.

Dr4Film · 02-21-2015, 10:19 AM

Here is the Onan Generator Engine Break-in Procedure and Exercising Procedure as stated in my owners manual. I have the 7.5 KW Onan.

Based on your previous posts it appears that you had followed the procedures properly.

BREAKING IN A NEW ENGINE

Proper engine break-in on a new genset or on one
with a rebuilt engine is essential for top engine performance
and acceptable oil consumption. Run the
genset at approximately 1/2 rated power for the first
2 hours and then at 3/4 rated power for 2 more
hours. See LOADING THE GENSET (Page 8).
Proper engine oil and oil level are especially critical
during break-in because of the higher engine temperatures
that can be expected. Change the oil if not
appropriate for the ambient temperatures during
break-in. See ENGINE OIL RECOMMENDATIONS
(Page 5). Check oil level twice a day or every
4 hours during the first 24 hours of operation and
change the oil and oil filter after the first 50 hours of
operation.

EXERCISING THE GENSET
Exercise the genset at least 2 hours each month if
use is infrequent. Run the genset at approximately
1/2 rated power. See LOADING THE GENSET
(Page 8). A single two hour exercise period is better
than several shorter periods.
Exercising a genset drives off moisture, re-lubricates
the engine, replaces stale fuel and removes
oxides from electrical contacts. The result is better
starting, more reliable operation and longer engine
life.

Dr4Film ----- Richard