Valve adjust interval. Time a factor ?

[livi]

As I recall the valve adjust interval is 15k miles according to the manual. The same manual also states 7.5k miles for oil change.

Now. A lot of owners adjust valves once or every other year. Disregarding the fact that the car has been driven much less during that time. Probably the same with oil change. Once a year no matter what mileage. With oil I can see the point. Especially with long sleeping winter months, condensation etc. But what about the valves. Does time alone spell mis-adjustment ? Sure, ten years might make a difference, but two or three ?

According to the "every other year-rule" I am due for an adjust this summer. But I have only driven 5k miles since the last adjust two years ago.

Mind you, I am not being lazy - on the contrary I am looking forward to give it try myself. Simply eager to learn and understand how this marvelous boxer six works.

Thanks!

[wholberg]

I adjust mine when the valves become noisy, which has always been concomitant with a loss of power and rougher idle. This appears to me to be more related to mileage than time.

[livi]

Right. Looser - more noise. Possible to detect. But what about tighter - no noise. Risky business ?

[Porsche virgin]

I've been wondering the same thing. I did mine about a year and a half ago, but I've only driven about 3k miles.

[jmohn]

Milage not time. In fact I let my last adjustment go over 20K (about 2 driving season, I got busy, OK?) and, still, only 3 valves needed adjustment, and then only slightly. Now, my car is my summer daily driver and rarely sees extended high RPM use, I'm certain a track car (or extremely aggressivly driven street car) would need adjustment much more often.

Jerry M
'78 SC

[911pcars]

If you don't use it, you don't lose it.

Sherwood