Some time ago there was a thread in this (or another?) forum about why the valve noise changes during warm up of a 914/4 engine, something like this :

1. Engine cold, valve noise almost none thanks to oil being cold and thick.

2. Engine warms up, barrels expands quicker than the push rods making valve lash bigger giving more noise.

3. Engine fully hot, also push rods have now expanded making smaller lash and the valve noise goes down remarkably from Point 2.

My own 914/4 seems to follow these phases but not sure if I remember the theory right can someone please correct?


/Lars S

I can add that all my type4 Engines have followed these phases.
Comments anyone?


/Lars S

My engine makes all kinds of noises in ALL phases. It has since it was new. It has always sounded like a thrashing machine. It has for the last 25,000 miles.

I like it. It's got a taste of that old VW tweedle, add in the fact that you can hear the valves and such do their thing then the carbs on top of that and it all comes together to form the air-cooled symphony.