Changing your motor oil: step by step

What to have ready beforehand

The most common reason an oil change gets abandoned halfway is a missing small part, usually the sealing washer for the drain plug. Lay everything out before you start:

• Motor oil in the prescribed specification and quantity, plus a little spare for topping up. You will find the right packs in the motor oil range.
• A new oil filter and, depending on the design, the matching seal kit. Filters are in the Filters category.
• A new sealing washer for the drain plug. The old one is deformed and will not seal reliably a second time.
• A drain pan with more capacity than the fill quantity, a funnel, gloves, rags and some oil absorbent just in case.
• A socket or ring spanner for the drain plug, an oil filter wrench or the right socket for the housing cap, and a torque wrench.
• Sturdy drive-on ramps or axle stands. A jack on its own will not hold up a vehicle that someone is working underneath.

Warm up the engine, but not to scalding hot

Warm oil is thinner, drains faster and more completely, and carries along the suspended particles that would long since have settled in the sump when cold. Ten to fifteen minutes of driving, or reaching normal operating temperature, is enough. Straight after a motorway run, on the other hand, the oil is so hot that a loosened drain plug can cause scalds. In that case let the engine stand for a few minutes and wear gloves.

Raise the vehicle safely

Work on level, firm ground and secure the vehicle against rolling away. Ramps are usually the simplest solution for an oil change because the car stays level while the sump remains accessible. Many modern vehicles have an undertray that has to be unscrewed first; the clips break easily, so patience pays off here rather than force.

Draining the oil

1. Remove the oil filler cap at the top so that air can flow in and the oil runs out evenly.
2. Place the drain pan under the drain plug, allowing for the stream: when the plug comes loose it first shoots well out to the side.
3. Loosen the drain plug and make the last turn by hand. Let the oil drain completely, which takes several minutes.
4. Fit a new sealing washer, clean the plug and its sealing face, and tighten the plug to the torque given in the handbook. Overtightening damages the thread in the sump, and that is an expensive repair.

Extracting the oil through the dipstick tube is expressly provided for by the manufacturer on many engines and is standard practice in workshops, because the vehicle does not have to be raised. It does not work on engines with a curved dipstick tube or without a dipstick, and it does not always reach the sediment at the bottom of the sump. If the manufacturer allows both methods, both are fine.

Replacing the oil filter

The filter is replaced at every oil change, not every other one. There are two designs. The spin-on filter is a sealed canister with its own gasket; the gasket is lightly coated with fresh oil before fitting and the filter is then tightened by hand, not with the filter wrench. The cartridge filter sits in a housing in the engine bay, is replaced together with all the O-rings from the kit, and has a specified torque for the housing cap. In both cases: look for the old gasket and remove it before the new one goes on. Two gaskets sitting on top of each other are the classic cause of an oil leak shortly after a service.

Filling with fresh oil

Start by pouring in about 80 percent of the specified quantity and keep the rest aside. Then start the engine: the oil pressure warning light must go out within a few seconds. Let the engine run briefly, switch it off and wait a few minutes for the oil to run back down into the sump. Only then top up until the level sits between minimum and maximum, preferably in the upper half. Too much oil is not a safety margin: the crankshaft churns into the oil, the oil foams, and the excess can find its way through the crankcase breather into the intake and the particulate filter.

Checking the oil level properly

Measure on level ground with the engine switched off. Vehicles with electronic oil level measurement require a certain oil temperature for this and only report the reading in the on-board menu after a waiting time. Check the level once more after the first drive and take a look under the car: small drips at the drain plug or filter housing show up immediately.

Service indicator and records

Reset the service interval indicator, otherwise the vehicle keeps counting from the old oil age. Note down the date, the mileage, the oil used and its approval. For workshops that is standard procedure anyway; for private vehicles it is the evidence that counts when selling the car and in goodwill claims.

Disposing of used oil properly

Used oil belongs neither in household waste nor down the drain. Under German law, anyone who sells motor oil must take back used oil free of charge in the quantity they sold; the purchase receipt is the proof. The same applies to the used oil filter and to oily rags, which count as oil-contaminated waste. How returns work with us is explained on the Waste oil returns page.