Why did my engine fail after valve job Audi and Volkswagen 1.8-liter
If you’ve had a valve job on your Audi or Volkswagen 1.8-liter engine and then encountered catastrophic engine failure, the blame may rest with the shop doing the work.
Audi and Volkwagen have investigated the engine failures and found that the shops were not following official recommendations.
First, Audi and Volkswagen recommend new hydraulic lifters when doing a valve job. If the shop reuses the oil ones, they must be thoroughly cleaned, refilled, and properly adjusted. Any contamination in the lifter metering device can cause the valve to contact the piston. On installation, the lifter and cam lobes MUST be coated with an extreme pressure grease. New oil MUST be used in the engine on startup.
The manufacturers warn that the new lifters must be allowed to settle in the head for 30 minutes after installation. Ideally, the engine should sit overnight. That allows excess oil to drain. If the shop did not allow that settling time, the lifter can cause the valve to open too much and contact the piston. After settling, the shop must rotate the engine BY HAND for two complete engine cycles to make sure the valves aren’t contacting the pistons. If the shop skips this step, the engine will suffer immediate failure.
Finally, Audi/VW recommend replacing all the valve keepers instead or reusing the old ones. The valve stems on these engines are so small, that any wear can cause the valve to not seat properly.Posted on by Rick Muscoplat