Does the Audi A6L 2.5 Naturally Aspirated Engine Burn Oil?
2 Answers
Audi A6L 2.5 does not burn oil, but it has normal oil consumption. Here is more relevant information: 1. Oil burning caused by ring pumping: Ring pumping is an inherent defect of reciprocating piston engines. All engines will experience oil burning to some extent, but the severity varies. Factors affecting ring pumping include the gap between the piston and cylinder wall, changes in piston ring tension, and wear of piston rings. When these parts malfunction, excessive oil consumption occurs, which is referred to as oil burning. Symptoms include faint blue smoke from the exhaust pipe, thicker blue smoke when accelerating sharply, smoke escaping from the oil dipstick, noticeable smoke at the exhaust outlet, and a significant drop in cylinder pressure. 2. Oil burning caused by valve stem seal leakage: When the valve stem seals age or are damaged, oil from the valve cover can enter the combustion chamber through the valve guides and participate in combustion, leading to oil burning. 3. Oil burning caused by turbocharger leakage: The turbocharger's intermediate section has a large flow of oil. If the seals on both sides of the turbine shaft are damaged, oil can enter the intake or exhaust pipes, resulting in oil burning.
I've been driving an Audi A6L 2.5L naturally aspirated model for five years, and this EA837 engine does have distinctive oil consumption characteristics. It features an aluminum alloy cylinder block with cast iron cylinder liners, where oil consumption up to 0.5L per 1,000 km is considered normal and not classified as oil burning. However, it noticeably increases after 100,000 km – my car started burning about 0.7L per 1,000 km at 120,000 km. The primary cause was incomplete oil scraping due to piston ring carbon buildup, which significantly improved after walnut shell blasting to clean the cylinder carbon deposits. For regular maintenance, never use oil with a viscosity grade below 40, and consistently using VW502-certified full synthetic oil can delay this process. As a side note, frequent short-distance driving accelerates carbon buildup, so I recommend occasional highway driving.
