After a wash the bodywork gleams, yet the tailpipe tip stays black with soot and greasy grime. Heat, exhaust particles and spray of mud, sand and water from the road make the exhaust one of the dirtiest parts of a car.
The pipe does not need regular cleaning for the engine to run, but a clean chrome or stainless tip noticeably freshens the look of the car. More importantly, care protects the metal from rust, which winter road salt speeds up every year.
What you will need
Important: Work only on a completely cold pipe: after a drive it stays hot enough to burn for a long time. Aerosols are flammable, so never spray them on hot metal or near an open flame.
Step 1
Wash the pipe with soapy water
Just like the bodywork, wash the exhaust with warm water and car shampoo. Wet a sponge or soft brush and go over the outside of the tip and the rim of the outlet. The water turns black with soot quickly, so change it as often as needed. Wipe off remaining soap and dirt with a damp cloth.
A steam cleaner also works well, as steam softens deposits, though not everyone has one.
Step 2
Polish the tip
Run a finger over the clean pipe: if almost no dirt comes off, move on to polishing. Choose a polish suited to your metal, chrome or stainless. It removes a thin layer of discolouration and oxidation, restores the shine and adds protection. Buff with microfibre until the polish disappears.
Step 3
Protect against rust with WD-40
Spray WD-40 Smart Straw onto the pipe, leave it for a few minutes and buff with microfibre. It displaces moisture, lifts the last of the grime and leaves a thin film that guards against rust, oxidation and discolouration. The pipe sits in an awkward spot, so flip up the straw and aim precisely to keep spray off the bumper.
Step 4
Inspect hangers and clamps
While you are at the exhaust, check the rubber hangers and clamps. If the bolts are rusty and will need undoing one day, treat the threads in advance with WD-40 Specialist Penetrant: it works into the rust and will make a future repair easier.
Step 5
Repeat regularly
Wipe the tip every time you wash the car. Refresh the WD-40 Multi-Use protective layer every 2-3 weeks, and more often in winter when roads are salted. Any undried residue burns off at the first warm-up, so apply thinly and wipe off the excess.
Tip: If thick black soot or oily drops constantly appear at the outlet, it is no longer a cleaning issue: have the engine checked, as this can point to combustion problems or oil consumption.
What next
A clean, protected tip lasts longer and will not turn rusty by spring. If the pipe has rotted through or the silencer is booming, see our guides on replacing an exhaust pipe and repairing a silencer.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».