A stretched timing chain threatened serious damage — but catching the problem in time saved the engine from destruction.
A 2017 Audi A8 with nearly 330,000 km on the clock came to us with a characteristic metallic knocking sound from the engine, especially noticeable on cold start. The owner described it as a "rattle" that lasted a few seconds after startup and then disappeared.
Diagnostics revealed the main issue
On inspection we found a stretched timing chain — a serious fault that, if left unaddressed, could have caused the chain to skip and led to serious engine damage. Diagnostics also showed oil leaks in several places and clear signs of turbo and injector wear — engine performance was far from factory spec.
What we did
- Replaced the stretched timing chain with a full set of tensioners and guides
- Installed a new turbocharger to replace the worn one
- Replaced all injectors
- Fixed every oil leak found — crankshaft seals, valve cover gasket, oil pan
- Full inspection of the lubrication system after reassembly
The engine is restored without opening up the block: the knocking is gone, the turbo and injectors run to spec, no oil leaks remain.