Oil Change Basics Parts that Keep Your Jeep in ShapeIt doesn't matter what kind of Jeep you have, or what year your Jeep is, it will need regular maintenance to keep it running. The most important would normally be changing your oil and filter. Since the oil lubricates your engine inside, and the engine is the heart of your Jeep, you want to take care of it as best you can. Changing your oil regularly is an investment over time, to help prevent, or slow down, internal wear, and keep all those fast moving parts in harmony. So what are some of the basics about oil and changing it? Let's start with the simple thing first, the Jeep oil filter. One most vehicles there will be an oil filter (well except for say, the old VW bugs, they had more of an oil strainer). In the USA, we are more familiar with the "spin on" filter. A filter that is self contained, and you simply rotate and screw off the old filter, and screw on the new one. For the most part, an oil filter is located underneath the engine, or on the side (though, on some engines, it can be on top, like an Mazda Rotary). The filter will have a rubber gasket at it's base. This meets up with a machined surface on the block (or an oil adapter, as some engines have), and seals against oil leaking out of the filter where it meets the engine. These filters are usually easy to swap out by hand, or with a simple oil filter wrench tool. Here is a typical spin-on Mopar oil filter -
The next common type is a "canister" filter. The filter itself fits inside a "can" (canister). The cansiter is the housing that holds the filter, protects it, and holds the oil inside. You can't see the actual filter from the outside, you just see the canister. These types of filters have been around the longest, back since cars began. They have been used in Europe for the most part on through the years, but now American vehicles are starting to use them. It's hard to say one is better than another, it's whatever the car designers and engineers want to do. Since Jeep is owned by Fiat, a European country, it's not surprising to see them go to this kind of filter (though the original WWII Jeeps used a canister filter as well, so obviously the design has been around awhile). To change these types of filters, you have to remove the canister. It's usually held on with a bolt that runs down the center, and bolts it to the block. Once the bolt is removed, the can comes off, and the filter is loose inside. You still have a rubber seal or gasket, that seals the can up against the block or oil adapter, so it can sometimes be a handful to juggle it all when re-installing. Here's a canister type air filter:
Here's a canister filter housing, that holds the filter inside -
Another aspect of a Jeep oil change is the drain plug. Typically the drain plug will be on the oil pan, on the bottom of the engine, usually at it's lowest point, so all the oil will drain out. Some vehicles may have two if the the pan is divided, say over a cross member. (I seem to remember a Lincoln having this style at some time). The drain plug will screw out, and onced removed, allows the oil to drain out. Once the oil has drained, it's just a matter of screwing it back in. NOTE: great care must be taken to re-install the drain plug. The common mistake is to accidentally cross thread the oil pan hole. This can lead to a situation where the oil drain plug can't be installed correctly, and will leak. Sometimes the only way to fix the problem is to replace the oil pan, which can be an expensive repair. Always inspect the threads on the drain plug, and in the oil pan. Make sure they are clean and free of debris before re0installing. Take your time installing the plug once you are ready to do so. Many drain plugs will have a gasket around the threaded portion, made from rubber, nylon plastic, or copper. These should always be re-used, or, if the old one is worn, it should be replaced. This is to insure that you get a tight seal, and no oil will leak out. You don't want your engine to run out of oil, that can be catastrophic and expensive.
The top fill oil cap - I'm going to mention this, because caps can sometimes get lost. Or maybe you bought a used Jeep, and yours is missing. We do carry replacements for those. The cap on an older Jeep is usually on the valve cover somewhere. Sometimes, especially if the vehicle has been updated or has an engine mod, the cap may be a simple round cap that screws off, or comes off and on with a simple twist. In those cases the oil is poured directly into the valve cover. On newer engines, there is usually a specific tube, with a brightly marked cap or label, and the oil will be poured directly into that. Your best bet is to use a funnel, only because it will help prevent any sloshing of oil onto the engine, and you can get every drop into the engine. If your cap is missing, don't drive around without it. You don't want any dirt or debris getting into the engine, so always replace them as soon as you can if it's not there.
Jeep Engine Oil When it comes to engine oil, you'll hear a hundred different opinions, stories, myths, and wacky things about what to use. I could write a big thick book with all that info. But let's break it down to some basics. The vehicle manufactures use engineers and chemists to come up with the WEIGHT and TYPE of oil to use on their engines. I am not either one of those, and neither are most people. So it's a question of, do you want to stray from OE specs or not? The weight, and sometimes the type of oil, is mentioned on the OE oil fill cap (here's an example). That's easy to check once you have the hood up. If it's not marked there, check your owners manual for the correct weight oil and correct blend / type.. The weight of an oil is normally shown as something like "10W30".. The "W" stands for "Winter", and signifies the oil can be used at low temperatures. The numbers, 10 and 30, denote the viscosity. There are two numeral figures, because it's a multi-grade oil. The oil has 10 weight (thin) characteristics for when an engine is started, and 30 weight (thicker) when temperatures are high. If you have an older vehicle, and it used a straight weight oil (say. SAE30), that oil is one weight for higher temps. Modern engines use multi-grade oils. Some weights go as low as 0W20 oil, used on some European cars / engines. That's a pretty thin oil, but some of the reasons are to save gas mileage. Having the engine parts working, but using less friction and power, can increase mileage. (at least, that's one of the thoughts behind it to engineers). Also, a 0W20 oil is usually a synthetic. Regardless of the different weights of oils, your first choice should be to use the weight your vehicle manufacturer and engineers recommend. Conventional oil, synthetic oil, and synthetic blend oils for Jeep For the most part, conventional oil is what you would think of as regular oil, that's been used for decades. Made from oil that comes out of the ground and refined. Different companies add their own special blend of additives and chemicals, but they are all very similar.We carry Penzoil SAE conventional oil, and MOPAR SAE conventional oil. Synthetic oil is just that, it's a man made chemical and synthetic. Synthetic oils are used in performance applications, such as racing. So you know if it can hold up to that torture, it should work pretty well in a stock street vehicle. They have various chemicals, additives, and properties that prevent sludge inside an engine, and allow the oil to preform in higher and lower temperatures than a conventional oil. Some new vehicles specify Synthetic oil right in the owners manual (most of the time, it' s Mobile One). Cars such as GM's Corvette, a Mercedes or a Porsche. In cases like that you don't really get a choice on what oil to use. There are a lot of scientific and chemical reasons to use synthetic oil, and you will see a lot of this technical research data online, (far to much to mention here). We carry Royal Purple Synthetic oil, and Penzoil Synthetic Oils. Synthetic Blends are just as they imply. a mixture of conventional oil and synthetic oil. Some newer vehicles use and specify this kind of oil in their owners manual. Again, it's the chemical make up that oil and car manufacturers decide on, depending on the vehicle and the engines. Cost wise, these tend to be in the middle, more than conventional oil, but less than a full synthetic. So what oil should you use? When possible, you should use the proper weight and type oil specified in your owners manual, by the manufacturer of the vehicle and the engine. Can you switch from conventional oil to a synthetic oil? In most cases, yes. Again, as long as the vehicle manufacturer doesn't have a problem with doing so. For instance, Mazda recommends never using synthetic oils in their Rotary engines. So there are exceptions. Can I go longer intervals between oil changes with synthetic? Most oil companies mention that their full synthetic oils allow you to go longer miles between oil changes. But really, it depends on the conditions. To keep easy track of it, your best bet is to change the oil at the regular intervals that are mentioned in your owners manual. In severe conditions, such as desert high temps or cold winter conditions, you may actually want to do it more often. Stop and go traffic is also extra hard on engines and oil. Can I use a thicker oil than what is called for? On high mileage engines, where there might be some loose tolerances that have come about with engine wear, you can usually go a little higher with a thicker oil. You might go from 10W30 to 10W40 let's say. You don't want it to be too thick, because that will make the engine just work harder, which can effect mileage and possibly other things. It would be the same reason not to switch to a straight oil, like straight 40 weight. The engine has to rotate / operate through that thick oil and that really puts a strain on the engine and causes it to work harder. These are the basics of what to think about when changing your oil. Again, there's a lot of science, testing, and engineering when it comes to making different oils, so it can be debated all day long which one is better, why one is better than another, etc. The easiest thing to do is just follow the owners manual for the weight and type. In the end, it's important to change your oil on a regular basis. This is one of the best ideas you can do to help prevent engine issues later down the line, and in the coming years. See ya on the trails!