When To Adjust Valves

jyl · jyl's Garage

How often does valves need to be adjusted? My car got a valve adjustment at Kahler's about 13,000 miles ago. Based solely on the mileage, is it time to do it again?

What are the tell-tales that your valves need to be done? Sound, performance, "feel"?

I'm sure this has been answered before, but I guess I'm not too sharp with the search formulation today - a couple tries all returned something like 1,500 hits . . .

yelcab1 · 01-04-2004, 12:11 PM

15,000 miles the valve adjustment intervals. If it is out of adjustment, you will hear loud(er) slapping sound coming from the intake or exhaust valve covers. The engine will lose performance and the car will feel a little more sluggish.

When the 911 is all in tune, valves well adjusted, valve guides are good, it will sound like a good sewing machine. The sound of the air being sucked in and pushed through the engine is unlike any other sound in the automotive world. As unique as the sound of a Ducati rushing by (you know what I mean if you ever heard a Ducati).

jyl · jyl's Garage

Thanks. The car doesn't have so much of that smooth sewing machine / bicycle chain "whoosh" sound anymore. It seems lumpier, with some louder "clack-clacks", and occasionally even a subtle "pop" sound. This is the world's most useless description, I'm sure.

I guess there's a valve adjustment in my future. I have AX school in early Feb so going to try and get it done before then. Thanks.

Zeke · 01-04-2004, 06:30 PM

Do it! Every little thing I do to my car in the way of a tune up makes it smoother. These engines like things all adjusted correctly. And it shows, er, sounds.

pwd72s · 01-04-2004, 06:33 PM

It certainly doesn't hurt the car to check and set valves every 10,000...or even more often.

djmcmath · 01-04-2004, 07:05 PM

Not to hijack the thread, but I love to read other people's descriptions of car noises.

To get back on topic, Wayne's Projects book says you oughtta do the adjust every 6K for older (pre-78's) and every 10K for newer (post-78's) cars. OTOH, the PO had the valves done every 5K when he had the oil changed. My plan is to do it at oil changes, which happen at 5K. Sooner, if my car started sounding like yours. Good luck,

Dan

movin · 01-04-2004, 07:37 PM

I do it about every 7,000mi on my '87. A word of caution regarding engines just having a valve job done, do your valve adjustment much sooner because they sometimes can actually get tighter as the valve and seat wear initially!!!

yelcab1 · 01-05-2004, 06:31 AM

Quote:

Originally posted by jyl
Thanks. The car doesn't have so much of that smooth sewing machine / bicycle chain "whoosh" sound anymore. It seems lumpier, with some louder "clack-clacks", and occasionally even a subtle "pop" sound. This is the world's most useless description, I'm sure.

I guess there's a valve adjustment in my future. I have AX school in early Feb so going to try and get it done before then. Thanks.

Then it is time for a valve adjustment, spark plugs, rotor and cap (check and clean at least). If yours is a Carrera, then maybe you can only get it to a certain point, the noise will always be there if the valve guides are worn.