Changing your oil and filters at home

An oil and filter change is the best first job for DIY car maintenance. It’s simple, it’s satisfying, it saves money, and it’s the single most important thing you can do for an engine’s lifespan. Here’s how I do it.

Get the right oil

This matters more than anything else. Modern engines, especially diesels with a DPF, need oil that meets a specific manufacturer approval, not just the right thickness:

• VW Group “Pumpe Düse” diesels like the 1.9 TDI AWX in the A4 I had need oil meeting VW 505 01. These engines have a reputation for being bulletproof, but the wrong oil wears the camshaft.
• Citroën and Peugeot HDi diesels with a DPF, like my C4 Grand Picasso’s 1.6 HDi, typically need a low-ash oil meeting PSA B71 2290.
• Fords like the S-Max list a Ford WSS specification.

Your handbook gives the exact spec and capacity. Check the bottle lists that approval, not just “suitable for”.

What you need

• The correct oil, and a new oil filter for your exact engine
• A new sump plug washer. They’re crush washers, designed to be used once.
• Drain pan, filter tool, socket for the sump plug, torque wrench, funnel, gloves and rags
• Jack and axle stands, or ramps

Step by step

1. Warm the engine for a few minutes. Warm oil drains faster and carries more dirt out with it. Don’t get it hot.
2. Raise the car safely on axle stands or ramps, on level ground, with the handbrake on and wheels chocked.
3. Remove the oil filler cap. It helps the oil drain.
4. Drain the oil. Undo the sump plug (watch out, the oil is warm) and let it drain fully.
5. Change the filter. Remove the old filter, wipe the housing clean, and fit the new one with a smear of fresh oil on the seal. For cartridge filters, like on the 1.6 HDi, replace the housing’s O-rings too.
6. Refit the sump plug with a new washer, tightened to the specified torque. Overtightening strips the sump threads.
7. Refill with slightly less than the stated capacity, wait a minute, and check the dipstick. Top up to just below the max mark.
8. Run the engine for a minute, check for leaks around the filter and plug, then switch off, wait, and recheck the level.
9. Reset the service indicator. The procedure is in the handbook, or use a diagnostic tool.

While you’re there: the other filters

• Air filter: usually just clips or screws in the airbox. A clogged one hurts performance and economy.
• Cabin (pollen) filter: keeps the air inside the car clean and the windows clear. It’s often behind the glovebox.
• Fuel filter (diesels): less frequent, but important. After changing it, the fuel system must be primed, and many diesels have a hand primer bulb for this. Follow the procedure for your car, because air in a diesel fuel system can stop it starting.

Get rid of the old oil properly

Never pour it down a drain. Put used oil back in the empty containers and take it, with the old filter, to your local civic amenity site. Check with your council what they accept.

How often?

Follow the service schedule in your handbook, but for older diesels that do a lot of short trips, changing the oil more often than the maximum interval is cheap insurance. Oil is a lot cheaper than an engine.