I had both cams installed about three weeks ago and I have noticed a rattling noise from the engine.

At first I thought it was the engine rattle many people have complained about, but it wasn't noticable before the cams went in and temperature has nothing to do with the sound. I also thought I might need to use higher octane gas with the new cams, but that didn't work.

My question is this: Have any of you with aftermarket cams noticed valve clatter and if so, what did you do about it? I'm taking it back to my mechanic tomorrow, but I was wondering about other people's experiences.

 

I havent had any noise/problems with the installation of the cams. The engine is a little louder, but no rattle. A service mechanic at my mazda dealer has the same car you have with the cams, Ill ask him if he has had any rattling or problems.

 

If you used the Mazda cams, (J-spec intake, SP20 exhaust) then the base circles of the cams should be the same and not need shimming. If you used other aftermarket cams, then the valvetrain needs to be re-shimmed to adjust clearance properly. You should always check it anyway whenever the cams are changed. When I did mine, they were fine just dropping them in.