I know this is an old topic, but I'm getting conflicting information from my mechanic. After a recent valve adjustment, I noticed a couple valves were still audible on the left-side after warmup. He said that there may be some worn components in there or the oil may be too thin. He recommends 5W-50 oil on my 117k mile 3.2. Porsche used to recommend 15W-40 Shell, but changed to 0W-40 Mobil.

My question is this: do older engines require heavier oil due to increased wear? Wouldn't a newer engine have tigher tolerances and an older engine looser? Wouldn't the thicker oil for an older engine be better suited?

Finally, should I take the car back to the mechanic and have him check the valves again? Why would only a couple valves remain audible and the rest and silky-smooth?

 

My car has 180,000 km on it and I hear absolutely nothing from the valve and I run 20w50. I am going to be really hard presed to do the valve adjustment if it sounds and runs this good when I hit 20k. Especailly since I finally got the valve covers to stop leaking.

 

I don't think a heavier viscosity oil is going to change the noise from your valves that much. Esp. when you are talking synthetics. Either the valves were not properly adjusted, or there is wear. I use Royal Purple which quiets just about anything and is better than Mobil, or anything else I can think of. I'm not affiliated, yada, yada, yada.

Anyway, changing oil will probably not make your liftere noise go away.