Oil Analysis and what does it tell you. Any RV with an engine should have an oil analysis done before being purchased. This is for several reasons. The foremost is to tell you IF there is a potential issue with the engine or transmission. A standard oil analysis consist of 4 tests. Spectral – Spectral analysis will tell you what metals are dissolved into the oil. This is the warning stage. If there is a high reading of a metal then that is an indication of wear for that metal type. Note: this is dissolved metals not metal flakes or fillings. Once the metal starts to break apart, spectral analysis will NOT tell you. Fillings etc will be seen in the drain oil. The second test is the Insolubles test. This test tells you how good the filter is doing. Oil breaks down when exposed to heat and air. It starts to oxidize. This oxidation is removed by the filter. The cure for oxidation is to replace the filter. The third test is Viscosity test. Viscosity is the weight of the oil, 5W30 etc. It can change over time due to overheating, contamination, moisture and coolant getting into the oil. This is the indicator that will tell us when we have to change the oil. The final test is the Flash Point test. The Flash Point Test tell us the point at which the oil basically burns. All oil has a flash point. If the oil burns at or above the assigned flash point then everything is normal. If however, the oil burns below the flash point, it is contaminated and needs to be replaced.
This article is related to engine oil analysis. I will follow up with a transmission and a coolant analysis over the coming days. These Fluid analysis are relatively inexpensive and should be done prior to buying a used RV. They will tell you a great deal about the condition of the engine, transmission, cooling system and generator, that you can not see with the naked eye. It will be money well spent.