The brief
Mr Zuraimi's E60 came in with two problems, an engine that kept needing oil topped up, and a gear oil leak. So the job was two jobs: get to the bottom of the oil consumption, and find where the gear oil was going, and sort both in the one visit. When engine oil disappears with no puddle, it's being burnt, and the usual cause is the valve stem seals, the little seals at the top of each valve stem that wipe oil off the stem so only a film gets through. Over the years that rubber hardens and lets oil run down into the cylinders to be burnt, so the level drops. The gear oil leak was the trickier one, because what looked like a worn output seal turned out to be more than that, the transmission oil pump itself was leaking. Both stay broken until they're fixed properly, so we did the lot.
The diagnosis
The oil consumption pointed at the valve stem seals, and with the engine opened up they were hardened and worn, exactly the burning-oil picture. On the transmission side, the leak inspection went deeper than a worn seal and traced it to a leaking transmission oil pump. The rest of the engine and gearbox were sound otherwise. That's a valve stem seal replacement with the timing reset, plus sorting the leaking transmission oil pump, rather than papering over either one.
The work
On the engine, the valve cover came off, the hardened valve stem seals carefully extracted with the correct special tools, and new genuine BMW-spec seals fitted on every valve, everything reassembled and the timing set correctly to spec. On the transmission, the leaking transmission oil pump was attended to and the leak sealed, the gear oil topped to the right level. The engine and gearbox were run and checked, the oil levels confirmed holding. A road test confirmed a clean start with no smoke, the engine oil holding, no gear oil leak, smooth shifts, and no warning lights.
The outcome
No more engine oil disappearing, no gear oil leak, a clean start with no smoke, smooth running and shifting, the levels holding, and no warning lights, all sorted in a day. As Mr Zuraimi put it: "I have been a car owner for many years and have been to lots of car repair workshops. After visiting Revol Carz Garage for my car repair needs, they simply changed my typical view of a car workshop." The E60 went home with both issues fixed at the source. Hardened valve seals and a leaking transmission pump only get worse, so getting to the root of both and doing them together in one visit was the right way to leave the car.
