Perched on the engine block or oil filter housing, the oil pressure switch monitors lubrication circuit pressure and signals the instrument cluster warning light when pressure drops below the minimum safe threshold. On most vehicles it operates as a simple normally-closed switch that opens when oil pressure reaches working level; on engines with multi-stage lubrication monitoring it may also carry a variable-resistance sender that feeds real-time pressure data to the ECU and gauge. When the switch fails with an internal short, the oil warning light illuminates permanently even though the engine's pressure is perfectly healthy, sending many drivers unnecessarily to the workshop. Conversely, a switch that sticks in the closed position masks a genuine low-pressure condition — potentially the most dangerous failure mode, as a driver may ignore an oil warning they have been told is a faulty switch. A weeping gasket seat or cracked housing is the more common mechanical failure, typically presenting as a small oil weep around the switch body that worsens over time. Thread pattern and connector type vary significantly between engine families, so matching the OE number prevents fitment errors. VEMO and Meat & Doria supply the bulk of aftermarket switches covering Volkswagen, Audi, and Opel applications, with broad cross-compatibility across several group engine architectures.
Oil pressure switches can share the same thread size but use completely different connector bodies, sealing materials, or pressure thresholds — even across engines in the same manufacturer's range. The safest approach is to match the OE number stamped on your original switch or listed in your vehicle's parts catalogue against the references shown on this page. Your engine code, visible on the engine block or in the service booklet, is the critical identifier when the model name alone is insufficient to distinguish between engine variants.
A switch is a binary device: it either completes a circuit (warning light on) or breaks it (light off) at a fixed pressure threshold, typically around 0.3 to 0.5 bar. A sensor, also called a sender, produces a variable electrical signal proportional to pressure, allowing the ECU or an analogue gauge to display actual pressure values. Many vehicles use both: a switch for the low-pressure warning light and a sender for the dashboard gauge. Aftermarket equivalents from brands like VEMO cover both types, but the two are not interchangeable, so correct OE identification is essential.
No — not without first establishing whether the warning reflects a genuine loss of oil pressure or a failed switch. Stop the engine immediately and check the oil level with the dipstick. If the level is correct and the engine sounds normal with no rattling or knocking, the switch itself may have failed electrically. Have the circuit tested with a mechanical pressure gauge before driving further. If oil level is low, or if the engine is making unusual noises, do not restart — running an engine without adequate lubrication causes irreversible bearing and camshaft damage within seconds.
A permanently illuminated oil pressure warning light on an otherwise healthy engine — with correct oil level and no unusual engine noise — is the most common symptom of a switch that has failed in the closed position. An intermittent warning light that flickers at idle but extinguishes at higher revs may indicate a switch with a drifted pressure threshold rather than a true low-pressure condition. Oil weeping from the switch's threaded seat, visible as a slow accumulation of oil around the switch body, points to a failed sealing washer or cracked switch housing rather than an electrical fault.
Showing 100 of 2,628 Oil Pressure Switch OE numbers. Enter the OE on the main OE search to jump to any reference.
