RV 101® / RV Education 101®

Question: We own a motorhome and my question is; when we are not using it, and this could be for several months at a time, should I start the engine periodically?

Mark’s Answer: The quick answer to your question is yes, but there are other factors that need to be considered too. You didn’t mention if the motorhome was gas or diesel, or if it does or does not have an on-board generator.

The primary reasons for starting an engine during storage is to keep engine components lubricated. and prevent the fuel from tarnishing and gumming up. Both of these conditions can result in expensive repair bills to correct the problem. Diesel fuel can tolerate storage better than gasoline, but you still have concerns about keeping engine components lubricated.

Here’s what I recommend:

The first step is to change the oil and oil filter on the engine and generator prior to storage. Acids accumulate in used engine oil and can corrode engine bearings.

Next, add a fuel preservative to the fuel tank if the RV will sit idle for more than a couple months at a time. You can purchase fuel preservatives at your local auto parts store. Purchase enough to treat the amount of fuel in the fuel tank. Add the preservative and run the engine and the generator long enough for the preservative to get through the entire fuel system.

Note: I also recommend filling the tank with fuel to reduce the amount of condensation.

These preventive maintenance steps will help, but I still recommend starting and running the engine and generator at least monthly when it is in storage. Running the engine allows the oil to lubricate the dry components of the engine, and it helps keep the RV batteries topped off.

I also recommend starting and running the generator on a monthly basis. Make sure you run the generator with at least a half-rated load for an hour or two. You can locate generator load ratings in the generator owner’s manual.