Generator Exhaust Smoke

[Texas Clodhopper]

I'm dry camping with my genset set on auto start at low (12.2v) voltage. I noticed this morning when it started a pretty good puff of blue smoke. What say yea?

 

[Kevin D Pem]

Did it stop smoking quickly?

 

[Neemer]

Mine does the same, except it’s more white than blue IIRC. It’s done it since birth.

 

[Texas Clodhopper]

I've never noticed it smoking before and it only smoked for a few seconds at startup. It smoked at startup like a flooded gas engine.

 

[Texas Clodhopper]

Update: When it started this morning it puffed smoke for maybe 5 seconds and the generator was running very rough for a few few seconds, just like a flooded gasoline engine will do. Once it getsd over the rough running, it runs fine.

 

[Kevin D Pem]

So diesel?

 

[Rich W.]

So diesel?

Yes

 

[Texas Clodhopper]

Yes, diesel.

 

[BGMAC]

I’m not sure if those generators have glow plugs, but when I owned a diesel p/u I had a glow plug solenoid go out. Since glow plugs did not activate it would be hard to start, run rough at start and puff smoke until the engine cyl got warm.

It could also be a dirty injector maybe? I use to use injector cleaner additives in my fuel. I don’t know if you can with that DEF stuff anymore?

 

[MemoriesByTheMile]

How cold was the ambient temp?
I have noticed a bit of smoke on startup in 2 conditions:
1) when we didn’t run the gen at least once a month
2) when it is “colder”

The more regularly we run the gen, the easier/faster/cleaner it starts.

Once, when bored, was reading the owners manual - discovered that Onan states the gen should be run at least once a month for a couple hours. Hmmm, wasn’t doing that before, but we now have a reminder on the calendar to run it if needed.

 

[Kevin D Pem]

Was thinking air filter!

 

[sheridany]

How many hours since the last gen service? Rule of thumb is every 100-150 hours.

 

[Neal]

Sounds like your oil is over filled. These GENs do not like excess oil.

 

[Texas Clodhopper]

How cold was the ambient temp?
I have noticed a bit of smoke on startup in 2 conditions:
1) when we didn’t run the gen at least once a month
2) when it is “colder”

The more regularly we run the gen, the easier/faster/cleaner it starts.

Once, when bored, was reading the owners manual - discovered that Onan states the gen should be run at least once a month for a couple hours. Hmmm, wasn’t doing that before, but we now have a reminder on the calendar to run it if needed.

The temperature was mid 40's.
The genset has been running very frequently in the last 2 months and the AGS runtime is 2 hours. It normally will have a 40-50% load. While in storage, I have always run it monthly.

 

[newmarokie]

Run some injector cleaner in your fuel. Both engines will like it. Methinks you have a slightly leaky injector. Once it starts and pressures up and starts making horsepower the smoke goes away.

 

[Texas Clodhopper]

Run some injector cleaner in your fuel. Both engines will like it. Methinks you have a slightly leaky injector. Once it starts and pressures up and starts making horsepower the smoke goes away.

Any recommendations?

 

[newmarokie]

I've have never had any complaints with Lucas products. I am sure there are other good ones out there. We used to run some ATF in our fuel. It burns hot as hades, but will clean and lubricate. Just don't get you fuel checked until you have run a couple tanks through (red equals untaxed)

 

[Kevin D Pem]

Any recommendations?

My friend is sold on sea foam. While we are making suggestions, may be valve guide seals.

 

[Joe Hogan]

White smoke equals unburned diesel. Could be a number of reasons mentioned above. Glow plugs in cold weather, low compression at startup, blocked air filter, leaky injectors. Should eliminate the obvious issue first. We run diesel treatment every other fill up, Diesel Kleen.
Check glow plug circuit, air filter, oil level. Possibly service unit if it has 100+ hours since last service.

 

[Kevorows]

Blue smoke typically means your genset is burning oil. It’s probably a bit of oil slipping past the seals, especially if your genset hasn’t been used for a while. I’d check your oil levels and monitor it for a few days. If it’s just a quick puff, it’s usually nothing to worry about, but if the smoke gets thicker or more consistent, you might need to look into some maintenance.