Audi/AGB

Audi · Naturally aspirated

AGB

RS4·B5·1999–2001

"Project AGB on TD04 — this engine is a serious tuner's platform but demands constant attention even in stock form."

RISKY

42/ 100

"Legendary performance, brutal ownership costs ahead"

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Max HP

—

Torque Nm

7,500

Oil interval km

Recalls

Known issues

Known Issues

Turbocharger Failure (Twin K03/K04 Units)€2,000-5,000 · 80,000-150,000 kmCRITICAL

The twin-turbo setup on the AGB is a known weak point. Turbos suffer from oil starvation due to coked oil lines, leading to bearing failure. The complexity of replacing twin units on a transversely mounted V6 makes labour costs extremely high.

Excessive exhaust smoke

Loss of boost pressure

Whining or grinding noise from turbo area

Oil consumption spike

DIY: Expert

Oil Leaks (Rear Main Seal, Cam Cover Gaskets, Valley Pan)€800-2,500 · 100,000-200,000 kmCRITICAL

The 2.7 BiTurbo is notorious for widespread oil leaks. The valley pan gasket between the cylinder banks is particularly problematic and requires significant disassembly to access. Cam cover and rear main seal leaks are also common on high-mileage examples.

Oil puddles under the car

Burning oil smell

Oil mist on underbody

Low oil level between services

DIY: Expert

Timing Belt and Tensioner Failure€600-1,500 · 60,000-120,000 kmHIGH

The AGB uses a timing belt that must be replaced at strict intervals. Given the age of these vehicles (1999–2001), many are now well beyond multiple replacement cycles. A belt failure is catastrophic on this interference engine. Tensioners and idler pulleys must be replaced simultaneously.

No obvious symptoms before failure

Rough idle if belt has jumped a tooth

Engine will not start if belt has snapped

DIY: Expert

Water Pump Failure€400-1,000 · 80,000-160,000 kmHIGH

Water pump failure is widely reported on the 2.7 BiTurbo platform. The pump is typically replaced as part of the timing belt service but can fail independently. Overheating resulting from pump failure can cause serious engine damage.

Coolant temperature rising

Coolant loss

Noise from water pump area

Steam from engine bay

DIY: Expert

High Maintenance and Running Costs€1,500-4,000 · 0-999,999 kmMODERATE

The AGB engine is mechanically complex with twin turbos on a compact V6 platform. Access to many components is extremely limited, making routine maintenance disproportionately expensive. Independent specialist labour is strongly recommended over main dealer pricing.

Unexpected repair bills

Long workshop hours quoted for basic tasks

DIY: Expert

Buying Checklist

Demand documented timing belt and water pump replacement history with dates and mileage — walk away if unavailable

Inspect the valley between cylinder banks thoroughly for oil leaks from the valley pan gasket

Test both turbos under full load — check for lag, smoke, or uneven boost across the rev range

Check all oil feed and return lines to both turbochargers for blockage or carbonisation

Verify coolant condition and check for mayonnaise under oil cap indicating head gasket concerns

Use an OBD II scanner to check for stored boost, misfire, or sensor fault codes before purchase

Service Reality

Community oil interval7,500 km

Oil specification5W-40 fully synthetic, VW 502.00 specification

Est. ownership cost (2yr)€2,500–6,000 per year depending on condition and required repairs

Real fuel consumptionNo data

Also Found In

Audi S4 B5 (2.7 BiTurbo, related engine codes AJK/ARE)Audi A6 C5 2.7TAudi Allroad 2.7T

Buying Advice

The B5 RS4 with the AGB engine is a collector-grade performance car that demands respect and a serious maintenance budget — it is not a cheap used sports car. Buyers should only proceed if they can afford specialist workshop costs and are prepared for the reality that oil leaks and turbo wear are almost inevitable on a 20+ year old twin-turbo engine. A full service history is non-negotiable; without it, assume the worst and price accordingly. This car rewards dedicated enthusiasts with proper mechanical knowledge but will financially punish unprepared owners quickly.

Parts People Buy

Timing Belt Kit with Water Pump (2.7T B5)Link unavailable

5W-40 Fully Synthetic Engine Oil VW 502.00Link unavailable

Cam Cover Gasket Set 2.7 BiTurboLink unavailable

Turbo Oil Feed Line Kit B5 2.7TLink unavailable

Valley Pan Gasket 2.7 BiTurboLink unavailable

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