Oil, unlike wine, does not age well. Its viscosity – a measure of the resistance of a fluid to deformation at a given rate – does not take long to break down.
Oil thins as it heats up but thickens as it cools. The thicker it gets, the longer it takes to warm up and flow throughout the engine. As such, your motorhome engine’s oil is similar to all of us, it can’t just sit around without being active.
This also goes for the rest of your motorhome as everything needs to function to stay viable, but for this article, we are going to focus on the engine oil.
How Oil Goes Bad
Exactly how does your motorhome’s oil die? In a few faster-than-expected ways.
First, there’s the simple breakdown known as oxidation. Those little unseen oxygen molecules mix it up with your engine oil’s molecules and break them down over time, just like Ali did to Foreman.
As an example of oxidation, think of what happens to a peach once you break its skin. Oxygen molecules come swooping in like a turkey vulture on a carcass and will turn that peach brown practically before your eyes. Regarding oil, oxygen increases your motorhome oil’s viscosity, thereby making it perform worse from an efficiency standpoint.
Second, this leads back to oxidation, but say you took your motorhome out and towed a vehicle for a short trip and that was it for the camping season. Merely towing a vehicle makes your oil worker harder. Oxidation can, and will, double for every 20°F the engine’s heat goes up. Plus your motorhome’s engine runs hotter when towing.
Third, water contamination. It doesn’t matter where your motorhome is parked. Inside or out, swings in temperature cause condensation and condensation affects your engine. Condensation forms inside your motorhome’s engine and those droplets of water get into your oil and contaminate it.
When you take a trip of a good enough length you will see drips coming off your tailpipe. That’s condensation coming off the engine and those drips are a good thing to see. Plus, water getting into the oil can lead to sludge. I once knew someone who didn’t realize engine oil needed to be changed at all. Condensation and oxidation made the ‘oil’ so thick in the bottom of the pan you could stick the dipstick into it and create a sweet twangy country instrument.
What else can cause your motorhome’s oil to lose its effective viscosity? Gasoline.
Gas needs to volatilize and make its proper exit through the PCV (Positive Crankcase Ventilation) system. Short trips, or no trips, don’t allow your engine to heat up enough and get to normal operating temperature. Therefore, any gas hanging out in the piston and valve area didn’t wash through and therefore, gets into the oil and contaminates it.
Fuel dilutes oil, making it less effective and promoting the build-up of sludge. Sludge is a byproduct of overall contamination.
Changing Your Oil
And what oil should you use when you change it? If your motorhome is new and still under warranty, whatever the manufacturer recommends.
If it’s an older motorhome, chances are you will be better off with a synthetic-based oil. Synthetic oils are scientifically designed to last longer.
In summation, change your oil regardless of whether you drive your motorhome a lot, a little, or not at all. Not sure who coined this phrase, but oil literally is the “lifeblood of your engine.”
Any question or comment regarding your motorhome’s oil? Drop us a note in the comments below! Need your oil changed? Contact our service department.