P052E on Audi

The plastic crankcase oil separator / PCV assembly on the EA839 3.0 TFSI can crack or clog with sludge, dumping oil mist into the intake tract and disturbing crankcase pressure regulation. This contributes to elevated oil consumption, rough idle, extended cranking, oil-fouled spark plugs, and lean/misfire fault codes. Because the assembly sits beneath the intake manifold, the repair is labor-intensive (engine cover, intake manifold, and turbo inlet pipe must come off), turning a small part into a multi-hour job.

The C8 S7 (2020+) abandoned the 4.0T V8 for a 2.9-liter twin-turbo EA839 V6 with a 48V mild-hybrid electric supercharger. The EA839's vacuum-actuated factory water pump has a known mechanical design flaw and is widely described as a 'when, not if' failure, with NHTSA complaints and a class-action lawsuit citing failures well before 50,000 miles. Uniquely dangerous on this pump: it uses engine vacuum to operate a slide valve that controls the impeller, so when the pump leaks internally, coolant gets drawn into the engine's vacuum system, risking far more extensive damage than a simple external coolant leak. Owners report coolant loss, overheating warnings, and in some cases the temperature gauge entering the red zone. The original defective pump uses a 4-bolt pulley; the revised design uses a 6-bolt pulley.

The EA888 2.0 TFSI uses an integrated PCV (crankcase ventilation) valve in the valve cover whose rubber diaphragm and check valve are a known failure point across the engine family. When the diaphragm tears, the seal is lost and unmetered air enters, producing rough idle, possible whistling/screeching from the engine bay, a lean-running condition and sometimes increased oil consumption. It is a recurring, inexpensive-to-diagnose VW-Group fault that affects the SQ2's engine.