4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)
Audi · 4.2L NA V8 40V
1999–2009
"The 40-valve port-injection 4.2 V8 of the S4 B6/B7, S6 C5 and A6 4.2. Glorious sound, but the plastic guides and tensioners of the rear-mounted timing chains break up with age and heat - an engine-out job, and if the chain jumps a tooth the valves meet the pistons. Listen to a cold start and look for proof of the chain job."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 1
Plastic timing-chain guides and tensioner break up - engine-out repair
▸"Death rattle" from the back of the engine on cold start as the tensioner relaxes; misfires and cam timing codes; in the worst case the chain jumps teeth
The S4 B6/B7 V8 (BBK) has its timing chains at the gearbox end with plastic guides and tensioner that break up after many heat cycles, from about 97,000-161,000 km. Caught early the tensioner kit is replaced, but the engine has to come out: budget about GBP 2,500 (converted ~2,925 EUR); a parts-retailer guide quotes USD 1,500-3,500 (converted ~1,380-3,220 EUR). If the chain jumps teeth the valves hit the pistons. Cars with regular 0W40/5W40 oil changes often never fail.
Ask for the chain-job invoice; without it, price the job into the offer. No Greek-specific data found.
Models with 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) 2
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3.0L SC V6
View details → Compare: 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) vs EA837 3.0T SCTuning Potential
N/A — already high power
Frequently Asked Questions
Is the Audi 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) reliable?
The Audi 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) scores 60/100 with a verdict of CAUTION. It has 1 documented issues with total repair costs between €1,380 and €3,220.
What are the common problems with the 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)?
The most common issues are:
- Plastic timing-chain guides and tensioner break up - engine-out repair — critical, repair cost €1,380–€3,220, 97,000 km–161,000 km
What cars use the Audi 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)?
How much does it cost to repair the 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)?
Total potential repair costs for all 1 known issues range from €1,380 to €3,220. The most expensive issue is typically Plastic timing-chain guides and tensioner break up - engine-out repair.
What years was the 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) produced?
The Audi 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) was produced from 1999 to 2009. It is a 4163cc V8 petrol na engine.
Scores are calculated from documented issues, repair costs, and failure patterns across thousands of owner reports and technical sources. Learn about our methodology. Always inspect before you buy.