Originally Posted by coralreefer
When running our Onan RV QC 4000 for a few hours at a time I'm finding that I need to keep an eye on the oil level, as it needs to be topped off after a 1/2 day of running. Is this normal oil consumption?
Also, when removing the air filter in front of the Carburetor I notice some engine oil in the filter box, is this normal?
Coralreefer - Little bit more info please for us:
How many hours on your generator?
How do you use your generator typically? - While underway (driving) or parked stationary?
What weight of Oil do you use?
How are you checking it? Hot (right after running it) or cold/cool?
I'll give you my input on our Onan QC 4000, with almost 400hrs, mounted in our Class C motor home ( 3170DS):
If running our generator while underway
(70% of the time due to Texas heat):
Then what you've noted about oil consumption (really oil burping through air filter/carb) is normal for us. Sometimes there is but just a few drops found after a 6+ hr drive in the air filter assembly... Sometimes nothing really noticeable... Sometimes it's an ounce maybe (more than a few drops for sure... enough to start pouring out onto epoxied circuit control board). Over 4 years of ownership I've been able to correlate and explain the amount of oil consumption/burping directly to the quality of roads I traveled on and/or the amount of extreme angles off of level the rig obtained while the generator was running.
When running our generator while stationar
y (boon docking) and reasonably level:
No real measurable about of oil consumption (or burping) even for extended long run cycles 8+ hours.
I have really good real world experience to correlate this with all our travels. If your running your generator while underway, there will be oil consumption (really mostly burping through the air filter assembly). When we run our generator while driving (again about 70% of the 400hrs are while underway), my habit is to check the oil at the very end of each day's travels or the beginning of the next day. Check while cool
and add small amounts of oil at a time
if needed. I do not fill above the halfway mark
, as I see an increase of oil 'burping' if so.
To recap... IF
your oil consumption is indeed while underway
while stationary you don't have any real amount of measurable consumption. I feel it is normal
for this type of simple single cylinder air cooled 4 stroke engine. Take any lawnmower engine and operate it at near max output while shaking it and tipping it at angles, oil consumption does go up.