Audi A5 B8 1.8 TFSI

The EA888 timing chain tensioner is the most critical known issue on these engines. The hydraulic tensioner relies on oil pressure to keep the chain taut. As the ratchet mechanism wears, the piston retracts when the engine is off, causing a distinctive rattle on cold start lasting 1-30 seconds. If the chain skips teeth, valve-to-piston contact causes catastrophic engine damage. Pre-2012 Gen 2 engines (CDHB) are more commonly affected, typically between 80,000-130,000 km. The Gen 3 CJEB (2012+) has a revised tensioner that is notably more durable, though not immune. Preventive replacement of tensioner, chain, guides, and sprockets costs approximately 1,200-1,800 euros at an independent specialist. If the chain has already skipped, cylinder head repair runs 2,500-3,500 euros. VW/Audi issued revised parts. Cold start rattle is the most important pre-purchase check.

The EA888 Gen 2 (CDHB, pre-2012) engines are widely reported for excessive oil consumption caused by undersized piston ring oil return passages that clog with carbon deposits. Consumption of 0.5-1.0 litres per 1,000 km is common on affected cars, typically becoming noticeable after 80,000-100,000 km. Audi considers up to 0.5 litres per 1,000 km as within specification. Mild cases can be managed by topping up regularly at 200-400 euros per year in oil. Severe cases require piston and ring replacement, costing 2,500-3,500 euros due to engine strip-down. The Gen 3 CJEB (2012+) has revised piston rings and is significantly less affected, though not entirely free from the issue. Always check the oil level on inspection and ask about consumption between services.

The EA888 uses an integrated water pump and thermostat housing with a plastic body that is a well-documented failure point across the engine family. The seals and housing degrade over time, causing coolant leaks visible as drips or stains around the front of the engine. Symptoms include low coolant warnings, poor cabin heating, and possible engine overheating if left unaddressed. The integrated part costs approximately 200-350 euros depending on brand, with 3-4 hours labor. Total replacement cost is 500-1,000 euros at an independent specialist. This is common by 100,000 km and should be considered a near-certainty on higher-mileage cars. Metal impeller aftermarket replacements are more durable than the original plastic design.

All EA888 TFSI engines with direct injection suffer from carbon buildup on the intake valves because fuel is injected directly into the cylinder, bypassing the intake ports. Oil vapour from the PCV system bakes onto the valves, progressively restricting airflow. Symptoms include rough idle, cold-start misfires, hesitation, and reduced power, typically becoming noticeable between 80,000-120,000 km. The fix is walnut shell blasting of the intake ports, costing 400-800 euros at a specialist in Western Europe. The Gen 3 CJEB engine adds a secondary port injection system that partially mitigates this issue, making it less severe on 2012+ cars. Sustained high-RPM driving and quality fuel can slow the buildup but do not prevent it.

Front-wheel-drive A5 models with automatic transmission use the multitronic CVT, which has documented reliability concerns. Common failures include chain stretch causing jerking during acceleration (especially between 30-50 km/h), transmission control module faults causing limp mode and flashing PRND lights, and clutch pack degradation. Problems typically surface after 100,000 km, especially when fluid changes were neglected. Audi marketed the CVT fluid as a lifetime fill, but specialists strongly recommend changing it every 60,000 km. Gearbox controller repair costs around 800-1,200 euros; full rebuild runs 2,000-3,500 euros. Manual gearbox and quattro S-tronic models are not affected. Later multitronic units with 7-lamella clutch packs (from ~2012) are reportedly improved.

The original diverter valve uses a rubber diaphragm that degrades from heat and pressure cycling. When it tears, boost pressure escapes, causing sluggish acceleration, a hissing noise from the engine bay, and fault code P0299 for turbo underboost. The revised piston-style valve from Audi (part number 06H145710D) is far more durable and costs approximately 50-80 euros. Labor is typically under an hour. This is one of the most common failures on the EA888, affecting the majority of cars by 100,000 km, but it is also one of the cheapest and easiest fixes. Aftermarket alternatives from Forge or GFB are popular among enthusiasts.

The Audi A5 B8 uses a complex multi-link front suspension with multiple control arms per side. The rubber bushings in these arms deteriorate over time, particularly in the upper control arms. Symptoms include clunking or squeaking over bumps, vague steering feel, and uneven tire wear. This is a wear item rather than a design defect, typically appearing after 80,000-120,000 km. Replacement of all upper and lower control arms on one side costs approximately 500-800 euros using quality aftermarket parts (Lemforder, Meyle HD) at an independent shop. Audi dealer pricing can reach 1,200 euros or more. A complete control arm kit for both sides typically costs 300-500 euros in parts. Wheel alignment is required after replacement.

The PCV (Positive Crankcase Ventilation) valve contains a rubber diaphragm that is prone to tearing, typically after 80,000-120,000 km. When it fails, excessive crankcase pressure develops, pushing oil past seals and gaskets. Symptoms include oil leaks around the valve cover, rough idle, increased oil consumption, and faster carbon buildup on the intake valves. A failed PCV valve worsens nearly every other engine-related issue on this car. The replacement part costs approximately 40-80 euros, with 1-2 hours labor for a total of 150-350 euros. VW/Audi has updated the PCV valve design multiple times, so ensure the correct revision is fitted.