Adventures in RV Generator Oil and Filter Change

When you start living in an RV full time, you realize that some things are less adventurous than you imagined. Other times, you enjoy activities that you least expected to like. As pretty as they are, my wife does not like staying in RV parks. And so, we've been boondocking 90 percent of the time, which means we're staying in places with no power, water, or sewers.

There’s usually nowhere to dump our tanks. So, we've had to run our generator a bit. When we bought our 5th wheel last year, the generator needed more love than we thought, so we ended up getting a new one.

We bought the Cummins Onan 5500, a 50-amp generator. It's the one that goes specifically with our RV. We recently changed its oil for the first time and realized it’s an opportunity to teach other newbie RVers how to do it.  

As a full-time RVer, you should check the oil level of your generator daily. Your oil and oil filter change needs to be every 150 hours or annually. We hit 150 hours faster than annually because we're living in our RV full-time.

Getting to the nitty-gritty

You first need to prime your generator by holding the button on the far left. You should see a red LED light above the button. When the red light comes on, that means you've primed it. Then you press the “start” button.

Your generator will have an oil release valve on the right-hand side, close to the dipstick. You can check the oil level and quality by unscrewing the dipstick. Pull the dipstick out to see how the oil looks.

The top center of your Onan 5500 generator should have an air filter.

To pull the air filter off (pictured), press on the clips located on both sides of the black lid, and it will pop off. Our air filter still looked clean, so we didn’t need to change it. If yours also looks good, you can also return it.

It’s cheaper to do this on your own; a dealer would charge a lot for an oil and filter change. And this is coming from a guy that does not even change his own oil on his cars.

The oil filter is underneath the generator, and you’ll need a specific wrench to pull it out. The oil filter is the larger black part in the center. The oil drains from the thin black pipe on the left of the oil filter.

Other RVers suggest using heavy-duty diesel oil, but we use motor oil for our generator. It takes two quartz to fill the oil tank, so a gallon of motor oil should be more than enough.

You'll also need an oil pan, a new oil filter, and an oil filter wrench. You can get the Cummins Onan oil filter. A universal three job oil filter wrench will work better than other wrenches because it can grab onto the filter better. This wrench goes into a three-inch socket; I use the DeWalt brand socket set.

Warm up your generator for five minutes before draining the oil. Once it’s warmed up, you can turn the oil release valve until oil starts leaking out of the bottom.

Use the oil pan to collect oil from the bottom of the generator. Unscrewing the dipstick might help speed up the oil flow. Remember to always make sure you have the dipstick back on before trying to start the engine.

While the oil is draining, fill your new oil filter with oil before you stick it in. Once you’ve got all the oil out, you can close the oil release valve.

Now that the oil is drained, you can remove the old oil filter and replace it with a new one. We used the Onan oil filter. Make sure that you screw in the new oil filter tightly. Check your oil levels after running the generator for an hour to make sure nothing's leaking.

Also, check oil levels the day after an oil change to be safe.

Once the oil filter is replaced, you can pour the two quartz of oil into your generator. And you want to go slow, or it's going to leak all over the place. After you fill that up, you want to run it for five to 10 minutes, then check it to make sure it's not leaking.

So, after you've let your generator settle for a while, you can pull the dipstick out, wipe it, and check if your oil looks good and is not overfilled. Make sure after it's run for a while that it's not leaking.

As always, we can't wait to share more of our adventures with you.

To see reality what it’s like changing generator oil for the first time, check out this YouTube video: