One of the most common questions we get is regarding oil changes in diesel trucks.
First of all, viscosity is a term that all vehicle owners should know, especially people who live in extreme cold weather conditions or extreme heat conditions. Viscosity s a fluid’s resistance to flow, and the colder it is, the thicker the oil is. On the other hand, the warmer it is, the thinner the oil becomes. In Southeast Texas, the weather doesn’t get cold enough to need to worry about freezing temperatures and how that affects viscosity. However, it’s still a good term to know and understand especially if you change your own oil.
The most common type of motor oil people use in their diesel trucks is 15w40. If you live in colder climates, then you might run 5w30. In warmer climates like we have in Southeast Texas typically run 15w40. Always check your owner’s manual or your oil fill cap as a point of reference. If you have any questions about viscosity, let us know.
Oil filters are an important thing to get right. We recommend always going with the right length oil filter and right size cap. Some of the aftermarket caps don’t have the proper built-in snaps that allow the filter to mate up nice and snug when you replace the filter. If you drive a Ford, use the genuine Ford Motorcraft filter. You can never go wrong with using a genuine manufacturer recommended oil filter. Often times, people use cheaper filters that are not built quite as well, and over years of using lower quality oil filters in diesels, it can lead to issues.
While we’re talking about filters, if you have an upper mounted oil filter, you’ll want to remove your filter first and let the dirty oil drain down through the crankcase before you drain out the oil. Otherwise, some dirty oil will slowly drain and settle on the crankcase. Also, always change the o-ring when you swap filters. They usually come with the kit, so there’s no reason not to. Make you lubricate the o-ring with a little bit of oil so that it’s easy to remove the next time you change your filter.
Inspect Closely for Leaks
After you’ve drained the oil, put the drain plug back in, and put new oil in, go in the truck and start the engine and let your truck run for a minute. While your truck is running, do a walk around and inspect closely for any oil leaks. It’s a good habit to get into in case you get distracted or pulled away during your oil change. Check the oil to make sure you haven’t under or overfilled and you’re good to go. While you’re inspecting for leaks, keep an eye and ear out for anything that looks or sounds weird. If something’s amiss, and you catch it early, you’re far better off fixing it early than waiting until it’s too late and you have a much bigger – and more expensive – problem on your hands.
If you have a question or a problem with your diesel car, truck or RV, please give us a call at (281) 812-3085, and we’d be happy to help diagnose and repair the issue. Our auto repair technicians are experienced and we guarantee our work. Stay safe!