How to Change the Oil in Your Carby Richard Rowe
We tend to think of motor oil as just that stuff that keeps everything slick and sliding smoothly inside of a complex machine; but the truth is, it's as much a component of that machine as any piston, gasket or bearing. The molecules in your oil roll like tiny ball bearings between your engine's moving parts. They flex and squish to absorb impact, and they ferry heat away from those parts like a kind of supplemental cooling system. But this vital liquid component can't do any of those jobs very well once its molecules are cooked, broken or mixed in with contaminants -- all the more reason to change it before any of that happens.
Park the vehicle on hard, level ground -- preferably concrete -- and allow the engine to idle up to temperature. Hot oil drains faster and more thoroughly than cold oil, so it's important that the engine is at least warm. Turn the engine off. Find the factory jacking points under your car. Ideally, you want to lift the whole front of the car at once, by placing the jack under the front support crossmember, but often these either aren't present or aren't accessible. In these cases, you'll need to lift the car one side at a time, using the jacking points under the chassis, just behind the front wheels. Never put the jack under the engine. Set the jack stands under the jacking points to the rear of the front wheels and lower the vehicle onto them. Never get under a car supported only by a jack.
Pop the hood and find the oil filler cap. It's typically located on the top front of the engine, on or near one of its valve covers. Remove the cap. Don your gloves and safety glasses. Crawl underneath with a couple of rags and and your tools, and find the oil drain bolt on the engine oil pan. Be sure you're looking at the engine oil drain bolt and not the transmission drain bolt. They're easy to confuse on vehicles with the engine mounted sideways.
Place a drain pan under the drain bolt, and remove the bolt by first loosening it counterclockwise with a ratchet and the appropriate socket or bit, and then unscrewing it the rest of the way by hand, but be careful. Be ready to move quickly to drop the bolt into a rag -- the oil may be hotter than you think. Take the bolt out from under the car and clean it with a clean rag while the oil drains. Some vehicles, like Volkswagens and BMWs, require a new drain bolt or gasket every time you change the oil. Reuse the gasket on one of these vehicles and there's a good possibility the gasket will leak. If you see a rubber or plastic gasket on the bolt, call a factory dealer service department to double-check that you don't need a new one.
Reinstall the bolt after the oil has finished draining. It's a good idea to look up your engine's oil drain plug torque requirement, since some engines are more sensitive to proper plug torque than others. Most mechanics default to about 15 to 20 foot-pounds of torque, or just "snug" with a standard ratchet. They're very easy to strip, so don't go wild. Slide your oil drain pan under the oil filter for the next step.
Spin-On Filter Removal: Use a strap oil filter wrench or an application-specific oil filter socket to turn the oil filter counterclockwise and remove it. Oil filter sockets are convenient, even required, in some applications, where only the bottom of the filter canister is visible or accessible. Again, while spinning the filter off and taking it loose, oil will probably flow -- down your arm if you're not ready for it. Upend the filter into the drain pan.
Spin-On Filter Installation: Clean the flat filter mating surface on the block with a lint-free rag. Do the same with the threads on the filter mount. Use your finger to spread a thin coat of clean engine oil around the rubber sealing ring on the new filter. Screw the new filter onto the engine by hand until the gasket makes contact. Tighten it another three-quarters of a turn. Don't over-tighten it.
Canister- or Element-Style Filter Removal: Many vehicles, notably German cars, use a bare filter element tucked into a cylindrical housing with a removable cap. Some are accessible from the top, others from the bottom. If your canister-style filter faces down, you'll likely see a pressure-release valve in the middle of the cap. Push it up to drain the canister oil out before you remove the cap. Most caps use a protruding, cast-in nut or hex-fitting. Simply slip the appropriate-sized socket over this fitting, and use a ratchet and extension to break the cap loose and unscrew it. The filter element will usually come out with the cap; if not, reach into the filter housing and pull it out.
Canister- or Element-Style Filter Installation: Generally speaking, these kinds of filters require a new rubber O-ring on the cap; it should come with the new filter element. Pop the old ring off the cap, lubricate the new one with a bit of engine oil, and install it in the ring groove on the cap. Likewise lubricate both sealing ends of the filter element, and then either plug it into the cap, or push it down into the housing, depending on how it came out. Tighten the cap down just snug, but do not over-tighten it. These canisters and caps are usually plastic, and they tend to strip or break easily. Volkswagen calls for 16 foot-pounds of torque for the oil filter cap on its 2.0-liter TSI engine, for example. That's a fairly typical range for these setups.
Pull the dipstick out and clean it off. Refill the engine with the prescribed amount oil through the oil filler cap, using a clean funnel. It will likely read above the "Full" mark on the dipstick at this point. Look under the vehicle for leaks around the drain plug. Lower the vehicle to the ground, start the engine and allow it to run for 30 seconds. After 30 seconds, shut the engine down, and wait for two minutes while the engine oil drains back to the oil pan. This is necessary for an accurate level reading. While you're waiting, check again for leaks around the drain plug and filter; a flashlight can be handy here. Check your oil level again, and add as necessary to bring the level to the "Full" mark. You'll likely also need to reset your factory oil change or service reminder; you should find the information in your owner's manual, online, or from a quick call to your local dealer.
- Many vehicles now use lower engine covers, which may or may not interfere with oil change access. In these cases, you'll need to remove the lower cover. You'll generally find its bolts or screws arranged around the perimeter and along the bottom of the front bumper. These lower covers can make detecting leaks more difficult after you start the engine; your only option here is to leave the cover off, lower the vehicle, start the engine, check for leaks, then lift the vehicle again to install the lower cover. As you might have guessed, these kinds of vehicles are designed to be serviced on lifts, not jack stands. Don't run the engine or check the level with the car on jack stands.
- Vehicles with single-use drain plugs aren't that way because the manufacturer is just trying to get you to buy a new plug every oil change. These kinds of vehicles are designed to have the oil drained using a vacuum hose inserted through the dipstick tube. The drain plug is there as a redundancy. If you own one of these cars and plan on doing your own oil changes, you might want to invest in a manual vacuum oil drain pump. They do make oil changes a great deal cleaner, easier and faster, and they'll pay for themselves after the fourth or fifth oil change.
- Some vehicles require full or blended synthetic oils, but almost all vehicles can benefit from them. Top-shelf full synthetics can last two or three times as long as conventional oil, which offsets their premium price a bit. They can also save you money in the long term by reducing engine wear. Use the manufacturer-recommended oil weight, whether you're using synthetic or conventional oil. It will be listed in your owner's manual.
Things You'll Need
- Floor Jack
- Jack stands
- Protective gloves and safety glasses or goggles
- Socket set
- Extension -- by application
- Oil filter socket or wrench -- by application
- Drain pan
- Engine oil -- amount, type and weight by application
- New oil filter or filter element -- by application
- New filter O-ring or oil drain pan bolt gasket -- by application
- Torque wrench
- Clean, lint-free rags
- When you're operating under the hood, be aware that electric cooling fans can come on at any time, for no apparent reason -- even with the ignition off. Stay clear.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.