FAQ
TL;DR: Correct 2.0 ALT timing equals 16 chain pins between cam sprocket marks and belt marks aligned; “There are supposed to be 16 chain bolts” [Elektroda, T5, post #20385750] DIY errors often bend valves within the engine’s ~0.9 mm piston-valve clearance. Why it matters: Getting cam timing wrong can turn a 1-hour job into a full head rebuild.
Who this FAQ is for: Audi A4 B6/B7 owners and mechanics setting camshafts or chasing no-compression faults.
Quick Facts
• Chain link count between intake & exhaust sprocket marks: 16 pins [Elektroda, ociz, post #8153653]
• Tensioner pointer gap after two crank turns: 6–10 mm [Elektroda, wojtek250590, post #8153570]
• Tensioner bolt torque: 30 Nm [Elektroda, wojtek250590, post #8153570]
• Cam lock tool: VW/Audi T10008 or equivalent, ~€25 online “lock gives 100 % certainty” [Elektroda, wojtek250590, post #8153570]
• Typical exhaust valve replacement cost: €45–€70 per pair including seals [Europarts 2023]
How do I line up the camshafts on a 2003 Audi A4 2.0 ALT?
- Rotate the exhaust cam so its sprocket mark sits at 12 o’clock [Elektroda, wojtek250590, post #8153570]
- Fit the intake cam so 16 chain pins span the two sprocket marks [Elektroda, ociz, post #8153653]
- Engage belt with crank and exhaust-cam marks matching the front-cover windows.
Lock both cams with tool T10008 for accuracy.
Which mark on the variator do I use—arrow or wedge?
Use the small ARROW (or triangle) on the variator, not the locating wedge. “The suction roller is to be to the arrow for a million percent” [Elektroda, trrol, post #20409798]
What happens if I set the belt but misplace the chain?
A chain error shifts only the intake cam. You will lose compression but usually bend ZERO exhaust valves because the exhaust cam is belt-driven [Elektroda, trrol, post #20413275]
Can a wrong belt setting damage valves even when the engine is hand-cranked?
Yes. Belt misalignment can let pistons hit exhaust valves; users reported bending two valves despite hand-turning the crank first [Elektroda, matys1990, post #20407386]
How tight should the hydraulic tensioner be?
After two full crank rotations, the pointer-to-body gap must read 6–10 mm; if not, repeat the setup [Elektroda, wojtek250590, post #8153570]
Is a cam-locking tool essential or just helpful?
Essential for first-time installers. Lock T10008 prevents sprocket drift while you tension the belt, eliminating the common one-tooth error seen in forum failures [Elektroda, wojtek250590, post #8153570]
Three-step quick procedure to verify timing without special software?
- Hand-rotate crank two full turns clockwise.
- Re-check sprocket marks and 16-pin chain count.
- Measure tensioner gap (6–10 mm). All good = start engine. Any mismatch = reset.
Why did I lose compression on all cylinders after a timing job?
Chain installed with only 13 links between marks caused cams to overlap wrongly, producing zero compression [Elektroda, T5, post #20385750] Correcting to 16 links restored normal running.
What torque settings apply to the tensioner and cam caps?
• Tensioner pulley bolt: 30 Nm [Elektroda, wojtek250590, post #8153570]
• Cam bearing caps: Typical 10 Nm plus 90° on 8 mm bolts (Audi workshop manual).
Edge case: Can valve damage occur even with correct belt marks?
Yes. If the variator was swapped for an incompatible unit or not pre-locked internally, the cam may retard 20° under oil pressure and strike valves [Elektroda, zasilaczwarsztatowy, post #20411523]
What tools besides T10008 make the job easier?
• Cam sprocket holding bar (Lisle 36880 or OEM 3366) for safe bolt removal.
• 10 mm pin gauge to verify tensioner gap.
• VCDS to test variator advance once assembled.
How much slack is acceptable on the old chain?
Audi sets a service limit of 6 mm side-play; more than that risks jump under load [Audi TSB 2019].
