When my car is at idle or just started up there is a skipping sound coming from along the passenger side of the engine compartment. It is like something isn't firing right. Idle has been way up lately takes forever to come down to 750rpm (if at all) stays up about 1200 usually. Engine isn't cutting out or anything though....still zooms along pretty well.

The sound it makes kind of sounds like a sound a short would make or maybe a relay that is getting ready to fry.

Sometimes I hear a similar sound coming from the same place when I am going down the freeway. Reminds me of the sound a piston engine makes when it is knocking/pinging with bad gas. It seem most prominent when I have been caught in a higher gear with too low RPMs.

Any ideas of what I should look into first?

Thanks!!!!!!
:p

 

An exhaust leak at the junction of the exhaust manifold and the downpipe can make a strange noise as the gasket there starts to burn away. That's on the passenger side, down low. If that's your problem, be sure to use a genuine Mazda gasket to replace it. Others will burn away within a couple of hundred miles. Guess how I know that?...

 

you could also have a vacuum leak on the manifold very easy to check get some carb cleaner and spray by the engine while its on. if the idle goes up or smooths out that's your problem. its very common they originally came with paper gaskets that blew out easily now they have metal gaskets for the lower intake manifold. should only take a minute to check out. good luck.