Originally Posted by AW128i
Took my car back to my original dealer (I moved at the end of October and the previously reported service problems were at a new to me dealer that's now closer to home). They verified the problem and they're replacing all the exhaust valves. Looks like I'll be using my original dealer for service from here on out, despite them not being the closest dealer.
I'm curious, why are they changing the exhaust valves to fix a ticking sound caused by the hydraulic valve lash adjusters?
Did they do a cylinder pressures leak down test, that showed your exhaust valves are worn and not seating/sealing properly?
Per BMW, they can change the valve adjusters.
Why new exhaust valves?
As far as this ticking sound, in general, hydraulic valve adjusters commonly makes noise. And, in most of the cases it's not detrimental to the engine.
The ticking noise is often heard on cold start due to oil pressure needing to build up and pressurize the adjusters. Until the oil pressure goes up, and the oil thins enough so that it can enter the very small oil port to pressurize the adjuster, there will be a ticking sound.
Also, many times people misdiagnose their own engines by confusing injector tick from valve adjuster tick.
BMW isn't going to do a general recall as the NHTSA is not likely to issue a recall on a mechanical issue that is not related to safety. NHTSA doesn't do recalls for those types of issues.
BMW can issue an in house "recall", which they have, and it's called a "TSB". It's on a as-needed basis. If a customer comes in with a problem, the tech will use the TSB to see if it can address or fix the problem.
If the vehicle is under warranty, or the problem was documented during the warranty, then BMW will fix the issue.
This is why it is VERY important for those of you who suspect a valve lash adjuster problem, to report it to your dealer and have them document the issue during your warranty. If later it is determined that there is a problem that has a fix, you will have a remedy even after warranty.