Audi A4 B7
Weaknesses, engine ratings and buying advice
The Audi A4 B7 (2004–2008) is the B6 facelift — visually barely changed, technically refined. New engines, better build quality, same platform. Core topics remain: Multitronic and power steering — plus a new diesel issue.
Engine choice: The BWE (2.0 TFSI, 147 kW/200 PS) is the sport petrol — uses a timing belt, NOT a chain (unlike the EA888 in the B8!). Longlife 30,000 km intervals cause oil sludge → strainer clogs → turbo damage ($2,200–5,500). Strict oil change every 10,000 km. AUK (3.2 FSI V6, 188 kW) — refined but piston tilt (ring wear, extreme oil consumption, $2,200–8,800). Audi dropped the 3.2 FSI after 2008 — that says it all.
Diesel: BRE (2.0 TDI, 125 kW) — solid volume diesel. BUT: BPP/ASB/BKN (2.7/3.0 TDI V6) have the hex oil pump problem: balance shaft drive rounds off → oil pressure loss → turbo and engine damage ($3,630–9,350). No recall from Audi. Unpredictable between 80,000–225,000 km.
Multitronic CVT: identical B6 problem, $1,650–9,900. Power steering: "Audi disease" — squeaking, rack leaks ($770–1,980). Rear wheel bearings wear from 80,000 km.
Test-drive checklist: Multitronic jerk-free? Power steering at full lock? BWE: oil level + colour? 3.0 TDI: oil pressure warning on cold start?
2026 market: 2005–2008 with 75,000 miles $4,400–8,800. RS4 $27,500–44,000. Insider pick: 2.0 TDI (BRE, 125 kW) with 6-speed manual — most solid drivetrain. Avoid Multitronic and 3.2 FSI.
420 PS
RS4 · Benzin
420 hp NA V8, manual — the holy combination
Legendary!179 PS
2.7L TDI V6 Diesel
5 weaknesses
Good Choice344 PS
4.2L V8 FSI Benzin
8 weaknesses
Stay Away!Body Variants
The Audi A4 B7 is available as Sedan and Avant — choose your body type for specific insurance data:
Generations
Engine Overview
The Audi A4 B7 is available with 12 engine variants — from 101 to 420 hp. 5 variants had engine changes — the model year is crucial.
Second-generation unit injector engine with 77 kW. Reliable in everyday use, but sensitive to neglected oil changes. Dual-mass flywheel and turbocharger are wear items.
- !! Camshaft scored — typical PD weakness from 200,000 km
On the PD diesel the camshaft directly drives the unit injectors, creating high wear. Scored lobes and worn hydraulic tappets occur particularly with Longlife oil and short-trip use.
Symptoms: Ticking from the cam cover, rough idle, power loss, occasional black smoke - !! Timing belt — PD system increases belt load from 90,000 km
The PD system significantly increases belt loading. Replacement interval is 90,000–120,000 km depending on build year; always replace the water pump at the same time.
Symptoms: No warning on snap; occasionally faint chirping beforehand; engine stops - !! PD unit injector failure from 180,000 km
The unit injectors wear out with contaminated fuel or poor maintenance. Replacing a single element is often not economical.
Symptoms: Heavy juddering at idle or under load, individual cylinders cut out, significant power loss, loud diesel knock
+ 5 more engine weaknesses + vehicle weaknesses
Unit injector diesel with 125 kW in longitudinal installation. Strong and economical. Belt change every 120,000 km, dual-mass flywheel can wear.
- !! Oil pump hex-shaft drive wears out from 100,000 km
The hex-drive shaft in the balance shaft module drives the oil pump and wears prematurely. Failure causes an immediate oil pressure drop, turbocharger damage, and often total engine failure. Affects production years 2005–2009.
Symptoms: Oil pressure warning light illuminates, noise from the sump area, engine stops — often without warning - !! Cylinder head crack (less common than the 170hp version) from 150,000 km
Thermally induced cracks in the cylinder head cause coolant loss. On the 140hp BRE less common than on the BMN, but not impossible. More frequent on older examples with neglected maintenance.
Symptoms: Coolant loss without visible external leak, white exhaust smoke, overheating warning, loss of engine power - !! Dual-mass flywheel wear from 180,000 km
The dual-mass flywheel on the PD engine wears at higher mileages, typically from 180,000 km. Difficulty shifting and rattling on shut-down are the first signs.
Symptoms: Rattling on shut-down, vibrations when pulling away, gear selection difficulties, metallic clatter
+ 3 more engine weaknesses + vehicle weaknesses
Unit injector 2.0 TDI with 120 PS (89 kW) in the A4 B7. Entry TDI of the B7, low running costs. Prone to EGR valve fouling and injection pump failure at high mileage. Cam belt change every 90,000 km.
- !! Oil pump drive hexagonal shaft worn from 120,000 km
The hexagonal drive shaft of the oil pump rounds off from around 100,000 km. Sudden oil pressure loss without warning leads to turbocharger and engine damage. Engines built after November 2009 are not affected.
Symptoms: Sudden oil pressure warning (no precursor!), engine stumbling, engine knock — immediate engine shutdown required - !! Cylinder head gasket crack from 100,000 km
Until mid-2005, cylinder heads with insufficient wall thickness were fitted, cracking at an above-average rate. From mid-2005 a revised head with improved wall thicknesses was used — only older engines are affected.
Symptoms: White exhaust smoke after cold start, coolant loss without visible leak, exhaust smell in the coolant reservoir - !! PD injectors leaking from 130,000 km
PD injectors on the BMP can leak, causing starting problems and rough cold running. Reconditioning by a specialist is possible and cheaper than new parts.
Symptoms: Difficult starting after standing, rough running after start, misfires.
+ 3 more engine weaknesses + vehicle weaknesses
2.0-litre TDI with 140 PS — unit injector (PD) in the B7 generation. Cleaner combustion than the 1.9 TDI, but PD elements coke up from 120,000 km and can cause power loss. Oil pump drive susceptible to wear up to October 2009.
- !! Hex oil pump drive shaft shears — engine failure from 100,000 km
On the 2.0 TDI BVE (model years 2005–2009) the hex drive shaft in the oil pump module shears off. The oil pump fails instantly, usually at high revs — minimum damage is a dead turbo, often total engine failure. Repair costs 4,000–10,000 €.
Symptoms: Oil pressure warning light briefly illuminates (damage already done), engine noises, then engine stops — usually without warning - !! Camshaft scored from 150,000 km
On the 2.0 TDI BVE camshafts develop deep scoring, often from oil starvation or poor oil quality. Later consequence: metal particles in the oil and total engine failure. Camshaft replacement costs 1,100–3,600 €.
Symptoms: Progressive power loss, rough engine running, metal particles visible in oil, clattering from valve train - !! Piezo PD element failure — 2.0 TDI 170 hp from 100,000 km
The 170hp variant has piezo-controlled PD injectors which fail far more frequently than the simpler variants. Four elements cost around 2,000 € to replace. Ultrasonic cleaning possible from 375 €.
Symptoms: Heavy hesitation, power loss, increased consumption, rough engine running
+ 3 more engine weaknesses + vehicle weaknesses
Unit injector-free V6 diesel with VP44 distributor injection pump. Early production (up to 2003) with cast camshafts susceptible to severe valvetrain damage; from 2003 with roller rocker arms more robust. Belt change is extremely involved (entire front end must be dismantled). A well-maintained example can reach 400,000+ km.
- !! Camshaft and valvetrain wear from 140,000 km
Cast camshafts in early BFC engines (pre-2003) wear prematurely due to insufficient oil supply at low rpm. Rocker arms and hydraulic lifters score in; deep grooves on the lobes cause power loss.
Symptoms: Metallic ticking from the cylinder head on cold start, progressive power loss, rough running in the lower rpm range - !! Timing belt failure with engine damage from 120,000 km
Timing belt replacement is mandatory every 120,000 km. The job requires full front-end disassembly (bumper, radiator, headlights). Miss the interval and the belt snaps; open valves are hit by the pistons.
Symptoms: No-start after belt snap, loud engine noise just before failure, occasional squealing from a worn tensioner - !! VP44 injection pump failure from 200,000 km
The Bosch VP44 distributor injection pump fails after 180,000–220,000 km. Poor-quality fuel accelerates internal wear. The pump control unit electronics burn out due to overheated transistors.
Symptoms: Hard or impossible cold start, irregular idle, severe power loss, engine misfires
+ 3 more engine weaknesses + vehicle weaknesses
V6 common-rail diesel with 132 kW. Piezo injectors can fail expensively. Timing chain on gearbox side, involved replacement. Solid with good maintenance.
- !! Faulty Injectors from 120,000 km
On the BPP (EA896), injectors can become fouled or fail, causing irregular idle, juddering, and increased fuel consumption. Typically from 120,000 km onwards.
Symptoms: Blue smoke at cold start after standing, white smoke during operation, engine knocking, oil level above maximum - !! Leaking EGR Cooler from 150,000 km
The EGR cooler can crack or leak due to high temperatures and aggressive residues. Coolant enters the intake tract, potentially causing engine damage. Repair costs €1,100–2,200.
Symptoms: Gradual coolant loss, white-blue smoke from exhaust, rising temperature, unusual smell in the interior - !! Turbocharger Wear from 150,000 km
The high temperatures and boost pressures of the V6 diesel typically cause turbocharger damage from 150,000 km. Repair is very labour-intensive due to space constraints — engine removal is often required.
Symptoms: Noticeable power loss, black or blue smoke, elevated oil consumption, turbo whistling or bearing play
+ 2 more engine weaknesses + vehicle weaknesses
Robust V6 diesel engine with timing chain and a separate cam belt for the high-pressure pump. Critical issues: EGR cooler leaks and DPF problems with short-trip use. Very long-lived with correct servicing, but DPF/injector repairs are expensive.
- !! EGR cooler leak from 150,000 km
The EGR cooler on the 2.7/3.0 TDI engines is prone to leaks. Coolant enters the exhaust system or combustion chamber, causing gradual coolant loss and in the worst case hydraulic lock.
Symptoms: Coolant level drops without visible external leak, bubbling in expansion tank, white smoke on cold start - !! Piezo injector wear from 180,000 km
Piezo injectors wear at high mileages. Incorrect quantity correction factors in VCDS indicate worn injectors causing rough running and increased fuel consumption.
Symptoms: Rough engine running, increased fuel consumption, misfires, black smoke, fault codes for individual cylinders - !! DPF blockage due to short-trip driving from 120,000 km
The DPF cannot complete regeneration on frequent short trips as the required exhaust temperature is not reached. Additional deposits from EGR recirculation accelerate clogging.
Symptoms: Engine warning light, power reduced (limp mode), prompt to drive to complete regeneration, heavy smoke during regeneration
+ 2 more engine weaknesses + vehicle weaknesses
Large V6 diesel with up to 171 kW. Strong torque from low rpm. Piezo injectors and DPF are wear items to watch.
- !! Timing chain elongation from 180,000 km
The ASB is a chain-drive engine — with neglected oil quality or extended intervals the chain stretches. Cold-start rattling is typical; ignoring it for long risks engine damage.
Symptoms: Metallic rattle for 1–5 seconds after cold start — typical from 150,000 km. Audible under load too as wear progresses. - !! Timing chain tensioner 3.0 TDI — drive C from 120,000 km
The ASB 3.0 TDI V6 has a complex timing chain assembly with four chains. The chain tensioner for drive C is particularly prone to losing tension when oil pressure drops. Cold-start rattling is the typical warning sign.
Symptoms: Rattling on cold start that settles after a few seconds once oil pressure builds. Continued neglect leads to chain elongation. - !! Turbocharger wear from 200,000 km
The turbocharger on the ASB 3.0 TDI can fail with neglected maintenance or from carbon oil deposit build-up. Typical after 200,000 km or with irregular oil changes.
Symptoms: Power loss, blue smoke, whining from the turbo area, increased oil consumption.
+ 4 more engine weaknesses + vehicle weaknesses
Audi 3.0 V6 TDI with 204 PS (150 kW). Entry version of the V6 TDI in the A4 B7. Simple unit injector design, high mileages achievable without problems. Cam belt and EGR valve are the main service items.
- !! Piezo injector failure from 120,000 km
Like the BMK, the BKN piezo injectors tend to fail from around 120,000 km and seize in the cylinder head. All six must be replaced at the same time; the fault was corrected in 2007-onward production.
Symptoms: Heavy white smoke, blue smoke after sitting, engine knock, oil level rises due to diesel contamination - !! Timing chain and tensioner from 150,000 km
Four separate timing chains can stretch. Worn tensioners produce rattling; in the worst case the chain skips and causes total engine failure. Repair requires 15–20 hours labour.
Symptoms: Rattling on cold start, camshaft position fault codes, rough engine when cold - !! Timing chain stretch BKN 3.0 TDI from 100,000 km
The BKN 3.0 TDI A4 B7 has a known timing chain weakness. After tensioner replacement the chain may still be stretched and require full replacement. Typical from around 85,000 km in some cases.
Symptoms: Rattling on cold start for 2 seconds when engine is warm. Noise on restart after short standing time.
+ 3 more engine weaknesses + vehicle weaknesses
Simple naturally aspirated engine with 75 kW and proven technology. Robust and low-maintenance, ideal for city use. Cam belt change every 120,000 km.
- !! Timing belt idler pulley hardens — belt failure from 90,000 km
Timing belt idler pulleys can harden prematurely and cause belt failure. The change interval was therefore shortened from 120,000 to 90,000 km. Always replace rollers and water pump at the same time.
Symptoms: Whistling from belt drive, sudden engine stall, valve damage after belt failure - !! Water pump worn from 120,000 km
The plastic water pump impeller on the 1.6 MPI BSE is prone to blade fracture and leaks. Coolant loss and overheating risk if replacement is neglected.
Symptoms: Coolant loss, rising temperature, coolant smell - ! Valve stem seals brittle — oil consumption from 150,000 km
With age, the valve stem seals on the BSE 1.6 MPI become brittle and cause oil consumption. Not a piston ring problem, so no engine rebuild is needed. Repair is labour-intensive as the cylinder head must be partially disassembled.
Symptoms: Blue smoke on start-up, increased oil consumption (>0.3 l/1,000 km), oil smell from exhaust
+ 4 more engine weaknesses + vehicle weaknesses
One of the most reliable 1.8T derivatives (EA113) with 163 PS, fitted in A4 B6/B7. Typical 1.8T issues like ignition coil failure and defective crankcase ventilation occur regularly. Very manageable with synthetic oil and short change intervals (max. 10,000 km).
- !! Turbocharger Damage from Oil Coking from 180,000 km
The BFB/AWA 1.8T is prone to coking of the oil feed line to the turbocharger. Typical bearing damage on the K03 appears from around 180,000 km. The wastegate hose must be intact.
Symptoms: Whistling noise from the turbocharger, blue smoke under acceleration, power loss - !! Turbocharger K03 Shaft Play / Bearing Damage from 160,000 km
The standard K03 turbocharger shows radial shaft play and worn compressor wheel vanes at high mileages. A damaged wastegate hose leads to overboost and accelerated turbo wear.
Symptoms: Blue smoke clouds when pulling away after standing, whistling noises, wildly fluctuating oil consumption - ! Crankcase Breather (CCV) Failure from 80,000 km
The crankcase ventilation (CCV) valve and its hoses are a known wear item on the BFB. A cracked diaphragm valve leads to rough idle, crankcase pressure build-up, and oil consumption.
Symptoms: Heavy idle roughness, oil cap barely removable (vacuum), blue exhaust smoke
+ 3 more engine weaknesses + vehicle weaknesses
EA113 generation of the 2.0 TFSI with timing belt instead of chain — more robust in this respect than later EA888. The chronic weak point is the integrated oil pump module with balance shafts: insufficient oil pressure causes engine damage. The HPFP tappet wears on the revision-A camshaft within short intervals and must be checked regularly.
- !! Cam follower / high-pressure fuel pump from 60,000 km
The cam follower between the camshaft and high-pressure pump piston wears out rapidly on EA113 engines with Revision-A camshafts. Once the coating is gone, the pump attacks the camshaft directly — catastrophic failure possible.
Symptoms: Delayed startup, power loss at high rpm, hard starting. In advanced stages: metal debris in oil and engine noise. - !! Ölpumpenmodul / Ausgleichswellen unzureichend from 150,000 km
The combined oil pump/balance shaft module of the EA113 can fail in long-term use. Insufficient oil supply and balance shaft failure are the consequences. Replacement is expensive due to the integrated design.
Symptoms: Oil pressure warning light, rattling on cold start (approx. 2 seconds), engine noise at low rpm. Immediate action required to prevent engine damage. - !! High-pressure pump cam follower worn from 60,000 km
Critical EA113 issue: cam follower between camshaft and high-pressure pump wears through metal-on-metal contact. If undetected: damaged camshaft and pump — repair costs over €3,000.
Symptoms: Metallabrieb im Öl, Leistungsverlust, rauer Motorlauf, Metallgeräusche
+ 4 more engine weaknesses + vehicle weaknesses
Revised 2.0 TFSI with 147 kW for the B7 generation. Same oil consumption issues as AXX, but slightly improved piston ring sealing. Power output identical.
- !! Massive oil consumption from piston rings (series problem) from 80,000 km
Up to 785,000 engines from model years 2008–2011 affected: oil control rings too narrow (1.5 mm instead of 2 mm) coke up and allow oil into the combustion chambers. Consumption above 1 l/1,000 km possible.
Symptoms: Frequent oil level warnings, bluish smoke, oil consumption well above normal, sooty deposits in exhaust - !! Camshaft chain and tensioner worn from 120,000 km
The camshaft chain on the EA113 2.0 TFSI stretches with oil starvation or long service intervals. The chain tensioner and guide rails show wear with rattling as an early warning.
Symptoms: Metallic rattling from the timing chain area on cold start, camshaft sensor fault code, rough running - !! Crankcase breather defective from 100,000 km
The oil separator and crankcase breather on the 2.0 TFSI are known weak points. Defective membranes create vacuum in the crankcase and promote oil leakage.
Symptoms: Rough idle, whistling noises from engine bay, oil mist, mixture/injection fault codes
+ 2 more engine weaknesses + vehicle weaknesses
Older 30V V6 naturally aspirated engine from the ABC family, mechanically straightforward (no turbo, no direct injection). Suffers from early stretch of the internal camshaft chains, oil consumption and ageing seals. Chain replacement is labour-intensive.
- !! Chain elongation — internal camshaft chains from 120,000 km
The internal timing chains in the cylinder head stretch from around 100,000 km. Failed chain tensioners can no longer keep the chain taut; in the worst case it skips and the engine is destroyed.
Symptoms: Rattling and knocking on cold start at the cylinder head area, rough running and misfires, engine light with camshaft error codes - !! Idler and tensioner pulley — timing belt drive from 120,000 km
On the 2.4 V6, the idler and tensioner pulleys can fail — stiffening or squealing — before the actual belt interval is reached. Pulley failure can destroy the timing belt.
Symptoms: Squealing from the engine bay, belt flutter, worst case engine damage from a snapped belt. - ! High oil consumption from 80,000 km
Thirsty by design. Typical consumption is 0.5–1 litre per 1,000 km. On neglected examples, piston ring and valve stem seal wear add to the problem.
Symptoms: Engine oil level drops regularly, faint oil smell, no visible external oil leak
+ 2 more engine weaknesses + vehicle weaknesses
Quietest VAG V6 of its era, but inherently oil-thirsty. Known for timing chain tensioner problems in the cylinder head and leaking valve cover gaskets. With care, 300,000 km service lives are possible.
- !! Chain Stretch and Faulty Chain Tensioners from 120,000 km
The timing chain in the cylinder head of the 2.4 V6 tends to stretch from around 100,000 km. Hydraulic chain tensioners fail due to oil sludge blocking the oil supply.
Symptoms: Metallic rattling at cold start, irregular clattering, misfires and hesitation, engine warning light with camshaft fault - ! Elevated Oil Consumption from 80,000 km
The BDV is inherently thirsty for oil. Consumption of 0.5–1 litre per 1,000 km is not unusual at higher mileages. Switching to fixed service intervals and 10W-40 oil reduces the problem.
Symptoms: Frequent oil top-ups needed, faint oil smell in the cabin, no visible external oil loss - ! Valve Cover Gasket Leaks from 120,000 km
The valve cover gaskets on both cylinder banks become porous at high mileage. The camshaft adjuster seals are frequently affected as well. Replace both at the same time.
Symptoms: Oil stains under the vehicle, oil smell after driving, visible oil traces on the valve covers
+ 2 more engine weaknesses + vehicle weaknesses
High-revving V6 petrol with direct injection and 188 kW. Timing chain on the gearbox side, very labour-intensive to replace. Distinctive sound.
- !! Cylinder Bore Coating Detachment and Piston Slap from 100,000 km
The Nikasil coating on the cylinder bores detaches, leading to piston slap, heavy oil consumption and power loss. Engine damage is inevitable; repair is often uneconomical.
Symptoms: Heavy oil consumption, knocking from the engine, power drop, engine failure in extreme cases - !! Piston Slap / Piston Seizure from 100,000 km
The 3.2 FSI AUK is known for piston slap — pistons or cylinder bores wear and produce knocking noises with increased oil consumption. Repair is rarely economical given the costs involved.
Symptoms: Knocking from the engine, increased oil consumption, sudden power loss, loud slapping under load - !! Timing Chain Stretch — 3.2 FSI from 100,000 km
The timing chain on the 3.2 FSI can stretch and cause engine damage if it jumps. More common than on the 3.0 TDI. Rattling on cold start is the first warning sign.
Symptoms: Cold-start rattle, power loss, rough running, engine damage in the worst case
+ 3 more engine weaknesses + vehicle weaknesses
The BNS is a high-revving V8 with 420 PS at 7,800 rpm and an 8,250 rpm redline — piston speed at rated rpm: 25.4 m/s, identical to a 2012 F1 engine. FSI direct injection without port injection leads to the most aggressive carbon build-up of all 4.2 FSI variants: according to specialist workshops, no RS4 B7 reaches its rated power on the dyno — measured outputs were 347 to 385 PS instead of 420. Mechanical intake cleaning (BEDI) every 15,000–20,000 km restores power, chemical cleaning is not sufficient. Oil cooler connections corrode through galvanic corrosion (aluminium against steel) and are almost always seized at 15+ years of vehicle age. Water-cooled alternator costs four figures to replace. Oil changes every 10,000 km with 5W-40; at high oil consumption use 15W-50. Compression ratio 12.5:1 requires Super Plus fuel.
- !! Intake valve coking — no RS4 B7 ever reaches stock power from 30,000 km
The main problem of the BNS: FSI without port injection heavily cokes the intake valves. Specialist workshops measure 347–385 hp instead of the stock 420 hp. Mechanical BEDI cleaning every 15,000–20,000 km needed; chemical cleaning is insufficient.
Symptoms: Gradual power loss over months, rough idle, increased fuel consumption, sluggish throttle response in the upper rev range. Often only measurable on a dyno. - !! Timing chain on gearbox side — engine-gearbox separation required from 120,000 km
The timing chain sits on the gearbox side. Guide rails and tensioners wear; replacement requires engine-gearbox separation. With consistent oil changes (max. 10,000 km) the chain lasts significantly longer. Cold-start rattling is the warning sign.
Symptoms: Rattling on cold start that disappears after warm-up. At advanced wear, permanent chain rattling and engine warning light. - !! Camshaft adjusters wear with neglected oil maintenance from 90,000 km
Four camshaft adjusters wear from oil-deficiency-related abrasion. Oil quality and short change intervals (max. 10,000 km) are critical. Rattling on cold start and fault codes are typical signs.
Symptoms: Rattling on cold start in the camshaft area, power loss at low rpm, engine warning light with camshaft fault codes.
+ 5 more engine weaknesses + vehicle weaknesses
High-revving V8 naturally aspirated with direct injection, fitted in S4 B6/B7, RS4 B7, S5 B8 and R8. Timing chain sits on the gearbox side — repair requires engine removal. Oil change intervals of max. 10,000 km are mandatory. Short-trip use massively accelerates wear.
- !! Timing chain: tensioners and guide rails — THE main problem from 80,000 km
Chain tensioners and guide rails on the BBK wear prematurely, often from 60,000 km. Chain skips teeth → engine damage. Complete engine removal required; gearbox must be separated. Costs: 2,600–7,500 €.
Symptoms: Metallic rattling on cold start, progressively louder ticking at operating temperature, engine warning light, sudden power loss - !! Alusil cylinder bore wears — elevated oil consumption to engine failure from 120,000 km
The BBK uses Alusil-coated aluminium cylinders (not Nikasil). With sulphur-containing oil or long intervals the bore surface is damaged. Oil consumption rises to up to 4 L/1,000 km; result: piston seizure. Engine block replacement ~10,000 €.
Symptoms: Rapidly increasing oil consumption, blue smoke, falling compression, borescope reveals bore damage - !! Camshaft adjusters generate fault codes — limp home from 70,000 km
Camshaft adjusters on the BBK wear and generate camshaft deviation fault codes. Vehicle goes into limp-home mode. Adjuster replacement possible without engine removal; tensioners/rails require engine removal.
Symptoms: Rattling on start, engine warning light, limp-home mode, reduced engine output, rough idle
+ 5 more engine weaknesses + vehicle weaknesses
Vehicle Weaknesses
| Weakness | Cost | |
|---|---|---|
| Multitronic Gearbox: Juddering and Complete Failure The CVT Multitronic gearbox tends to judder when pulling away, rpm fluctuations and complete failure when not serviced properly. Control unit defects often appear from around 100,000 km. Symptoms: Juddering when pulling away, PRND display flashing, engine revving without forward motion, limp mode from 100,000 km | High |
Test Reports
Vehicle inspection (HU)
Average defect rate for the age bracket
2024Top Reported Issues
Alternatives
Explore more
Known Problems and Issues +
A total of 172 weaknesses have been documented for the Audi A4 B7 (2004–2008) — 161 engine-related and 11 vehicle-related. 10 problem engines: AXX (2.0L TFSI), BWE (2.0L TFSI), CCWA (3.0L TDI V6), BFC (2.5L TDI V6), AUK (3.2L FSI V6), CDHA (1.8L TFSI), BKN (3.0L TDI V6), BBK (4.2L V8 FSI), BVE (2.0L TDI), BNS (4.2L FSI V8). Typical issues affect Gearbox, Suspension, Electronics, Rust. Considered reliable: BSE (1.6L MPI), BPP (2.7L TDI V6).
A4 (BFC, 2002–2006) — Stay Away!: Camshaft and valvetrain wear, Timing belt failure with engine damage, VP44 injection pump failure. Power: 163–165 PS.
A4 (BFC-121, 2002–2006) — Be Careful: Camshaft wear from sliding rocker arms, VP44 injection pump ECU defective, Dual-mass flywheel wear. Power: 163–165 PS.
A4 (BKC, 2004–2008) — Be Careful: Camshaft scored — typical PD weakness, Timing belt — PD system increases belt load, PD unit injector failure. Power: 101 PS.
A4 (ASB, 2004–2008) — Be Careful: Timing chain elongation, Timing chain tensioner 3.0 TDI — drive C, Turbocharger wear. Power: 204–211 PS.
A4 (BRE, 2004–2008) — Be Careful: Oil pump hex-shaft drive wears out, Cylinder head crack (less common than the 170hp version), Dual-mass flywheel wear. Power: 163–170 PS.
A4 (BKN, 2004–2008) — Stay Away!: Piezo injector failure, Timing chain and tensioner, Timing chain stretch BKN 3.0 TDI. Power: 204–211 PS.
A4 (BMP, 2004–2008) — Be Careful: Oil pump drive hexagonal shaft worn, Cylinder head gasket crack, PD injectors leaking. Power: 120–126 PS.
A4 (BVE, 2004–2008) — Stay Away!: Hex oil pump drive shaft shears — engine failure, Camshaft scored, Piezo PD element failure — 2.0 TDI 170 hp. Power: 120–126 PS.
A4 (BSG, 2005–2008) — Be Careful: EGR cooler leak, Piezo injector wear, DPF blockage due to short-trip driving. Power: 163 PS.
A4 (ASB, 2006–2008) — Be Careful: Timing chain elongation, Timing chain tensioner 3.0 TDI — drive C, Turbocharger wear. Power: 232–239 PS.
A4 (CAGA, 2007–2015) — Be Careful: Injector failure caused by HP pump damage, EGR valve carbon build-up after update, Dual-mass flywheel wear. Power: 136–150 PS.
A4 (CCWA, 2007–2012) — Stay Away!: Chain tensioner cold-start rattle, Piston Slap — Alusil Block, EGR valve soot deposits. Power: 232–245 PS.
A4 (CANA, 2007–2012) — Be Careful: Timing Chain Stretches Prematurely, EGR System Clogged and Leaking, Piezo Injectors Wear Out at High Mileage. Power: 190 PS.
A4 (CLZB, 2007–2015) — Be Careful: Camshaft breakage from material defect, Piezo injectors wear prematurely, Timing chain system prone to wear. Power: 204–218 PS.
A4 (AGA, 2002–2006) — Be Careful: Chain elongation — internal camshaft chains, Idler and tensioner pulley — timing belt drive, High oil consumption. Power: 163–170 PS.
A4 (AGA-120, 2002–2006) — Be Careful: Oil consumption from valve stem seals, Camshaft adjuster leaking (oil loss), Timing chain tensioner weakening. Power: 163–170 PS.
A4 (BBK, 2003–2005) — Stay Away!: Timing chain: tensioners and guide rails — THE main problem, Alusil cylinder bore wears — elevated oil consumption to engine failure, Camshaft adjusters generate fault codes — limp home. Power: 344 PS.
A4 (AXX, 2004–2008) — Stay Away!: Cam follower / high-pressure fuel pump, Ölpumpenmodul / Ausgleichswellen unzureichend, High-pressure pump cam follower worn. Power: 200 PS.
A4 (BFB, 2004–2008) — Be Careful: Turbocharger Damage from Oil Coking, Turbocharger K03 Shaft Play / Bearing Damage, Crankcase Breather (CCV) Failure. Power: 160–163 PS.
A4 (AUK, 2004–2008) — Stay Away!: Cylinder Bore Coating Detachment and Piston Slap, Piston Slap / Piston Seizure, Timing Chain Stretch — 3.2 FSI. Power: 256 PS.
A4 (BDV, 2004–2008) — Be Careful: Chain Stretch and Faulty Chain Tensioners, Elevated Oil Consumption, Valve Cover Gasket Leaks. Power: 163–170 PS.
A4 (BWE, 2005–2008) — Stay Away!: Massive oil consumption from piston rings (series problem), Camshaft chain and tensioner worn, Crankcase breather defective. Power: 200 PS.
A4 (BNS, 2005–2008) — Stay Away!: Intake valve coking — no RS4 B7 ever reaches stock power, Timing chain on gearbox side — engine-gearbox separation required, Camshaft adjusters wear with neglected oil maintenance. Power: 420 PS.
A4 (CDHA, 2007–2012) — Stay Away!: Elevated Oil Consumption Due to Piston Rings, Timing Chain Elongation, Elevated Oil Consumption Due to Undersized Oil Scraper Rings. Power: 120 PS.
A4 (CDHB, 2007–2012) — Be Careful: Extreme Oil Consumption (Piston Rings EA888), Timing Chain Broken / Jumped, Coolant Pump Leaking. Power: 160–163 PS.
A4 (CALA, 2007–2012) — Be Careful: Rear timing chain — extremely expensive to replace, Four-chain timing drive — 3.0 TDI, Engine damage from bearing failure at 95,000 km. Power: 265 PS.
What to watch out for with the Audi A4? See the detailed listing of all engine and vehicle weaknesses in the sections above.
Frequently Asked Questions
What problems and weaknesses does the Audi A4 B7 have? +
What should I look for when buying a used Audi A4 B7? +
Which engine is recommended? +
Which Audi A4 B7 engine is the most reliable? +
Which Audi A4 B7 engine is the most fun? +
Is the Audi A4 B7 worth buying used? +
What horsepower variants are available for the Audi A4 B7? +
Last updated: February 2026 · All information without guarantee