The Driveway Oil Stain: Finding the Source Before Your Engine Finds Excuses

Depends entirely on how much oil you're losing and how fast. A very slow seep — a few drops per week — is something you can manage short-term by monitoring the level and topping up, while you book the repair. A leak that's dropping the oil level noticeably between journeys is a different matter: run the engine low on oil and the damage is fast, expensive and irreversible. Check the dipstick. If the level is dropping at any meaningful rate, stop driving and get it looked at.

Yes, easily. Oil landing on the exhaust manifold or downpipe burns off without necessarily dripping to the floor — the exhaust is hot enough to vaporise small amounts before they fall. If you have a burning smell with no puddle, it's worth having the engine inspected because the leak is often at the top of the engine (rocker cover, cam seals) where oil hits hot metal on the way down rather than making it to the floor.

Because the rear main seal sits at the very back of the engine, sealed against the crankshaft, and to replace it the gearbox (or on rear-wheel-drive cars, the engine) usually has to come out to access it. The seal itself costs very little. You're paying for the labour of a gearbox-out job, which is a multi-hour operation. If a garage quoted it cheaply, ask them exactly how they're planning to reach it.

It depends on the car. On many engines, an oil filter housing gasket or O-ring is a straightforward job — the housing is accessible, the gasket is inexpensive, and it can be done quickly. On some VAG diesel engines (the 2.0 TDI being the notorious example), the housing is plastic and prone to cracking as well as leaking at the O-ring, which makes it a bit more involved. Either way, it's worth diagnosing properly to confirm the exact source before replacing parts.

We stock common gaskets and seals for popular UK cars — things like rocker cover gaskets and oil filter housing kits for the cars we see most often. For less common makes, models, or engine variants we may need to order parts, which typically means a short wait rather than a same-day repair. We'll tell you upfront after diagnosing the leak what the part situation is and give you an honest ETA.

Could be any of half a dozen places — oil doesn't drip politely from the exact fault; it travels. The most common culprits are the rocker cover gasket (top of the engine, often seeps down the back and looks worse than it is), the sump plug or sump gasket (bottom of the engine, especially if the last oil change was done on the cheap), or the oil filter housing O-ring — particularly notorious on VAG diesels. A proper diagnosis means degreasing the engine and tracing the actual source, not just quoting the nearest expensive part.

Yes — and it's one of the nastier leaks on the list. The oil cooler (or its housing gasket on engines that use a coolant-fed cooler rather than an air-cooled unit) sits where engine oil and coolant run in close proximity, separated by a thin casting or gasket. When that seal fails, the two fluids cross-contaminate: you get a milky, caramel-coloured sludge on the oil filler cap, or a slight oily sheen on the coolant in the header tank. Left alone, it wrecks bearings and can cause overheating. Get it properly diagnosed — a mobile mechanic can identify which side is failing and fix it before it becomes a much more expensive conversation.