4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) vs EA839 2.9 TFSI twin-turbo (LK3)
Side-by-side reliability comparison
Higher reliability score
EA839 2.9 TFSI twin-turbo (LK3)
BUY
80/100
+20 points over 4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)
0
/ 100
CAUTION
4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)
Audi
0
/ 100
BUY
EA839 2.9 TFSI twin-turbo (LK3)
Audi
Specifications
4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)
EA839 2.9 TFSI twin-turbo (LK3)
Brand
Audi
Audi
Verdict
CAUTION
BUY
Reliability
60
80
Years
1999--2009
2016--present
Displacement
4163 cc
2894 cc
Layout
V8
V6
Type
Petrol Na
Petrol Turbo
Power
299--344 hp
330--450 hp
Known Issues
1
4
Total Risk Cost
€1,380--€3,220
€1,800--€3,700
Character
4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK)
"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."
EA839 2.9 TFSI twin-turbo (LK3)
"VW-Audi EA839 2.9 TFSI twin-turbo V6 (2016 on) in the RS4, RS5, S6 and S7 (outside Europe) and the Porsche Macan S/GTS, Cayenne S and Panamera 4/4S. It shares the 3.0's coolant-pump and crankcase-breather bulletins and Porsche lists a cylinder-head oil leak, but no piston or rocker-arm failure pattern was found for the 2.9. Hot-V turbos make big repairs expensive."
Issues Comparison
4.2 V8 40V (ARS/ASG/AQJ/ANK/BAS/BAT/BBK) 1
◆ CRITICAL
Plastic timing-chain guides and tensioner break up - engine-out repair
EA839 2.9 TFSI twin-turbo (LK3) 4
● MODERATE
Cylinder head oil leak - injector / camshaft adjuster area
● MODERATE
Oil consumption and carbon deposits (direct injection)
● MODERATE
Crankcase breather membrane failure - oil at the filler cap
● MODERATE
Coolant pump leak - coolant loss