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Frequently asked questions about cars and motorcycles

Why Can a Car Consume Oil?

Model: BMW BMW Various
Part: Engine oil

The case presented in the video discusses the N47 engine of a BMW vehicle with 90,000 miles, which was consuming oil abnormally. Upon opening the engine, they found deposits and sludge under the rocker cover. The issue is primarily due to the poor quality oil used during maintenance (even though it was done regularly). The deposits block the oil passages; the membrane under the cover gets stuck or damaged (and cannot be replaced separately); the oil vapour recovery system remains open, or closes poorly, causing the oil to be sucked in and burned in the combustion chamber. Other possible causes could be worn piston rings, allowing oil to pass into the combustion chamber; hardened valve stem seals; the turbo leaking oil; or deteriorated valve seals. The important lesson is that it is not enough to perform regular services; it is essential to use quality oils that are high-performing and meet the correct specifications. We have seen that poor-quality oil forms sludge and deposits that damage the engine internally.

Posted on 23 September 2026 by ScegliAuto

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