I have a fresh rebuilt engine with new plugs, coils, and spark plug wires. My engine sounds like its knocking..I will say that I have a gutted air intake box with no screens in the intake. but will that make the engine knock at idle? could it be one of my pulleys?

btw I made sure my plug wires were on securely

and i also cleaned the MAF sensor with CRC MAF CLEANER

 

Fresh rebuild engine? u mean u got it from Mazda? or you/someone's rebuild ?

 

Alamo Rotary rebuilt it. the only thing that makes me think its a pulley is it had the same exact sound before the rebuild

 

could be the alternator..

 

i have knocking at idle too..is yours an AT?

 

does it sound like this? http://www.youtube.com/watch?v=Hk5A6MFla4Y. this is what mine sounds like and i can't figure out what is wrong

 

It could be a bad vacuum valve on either the SSV or the APV. My SSV actuator valve is bad and it clicks or "knocks" at idle. Here's my vid:

CLICKY

 

yeah thats the sound i get. i will try to depress it manually and see if my sound goes away

 

that click is exactly what i have and it is the ssv (i think), i have a video here is the link:

http://www.youtube.com/watch?v=8dIJVcxbBpE

the noise stops if you just rest your finger on the bottom of it.

edit: btw my '8 is an AT

 

Most of the time it's not the SSV itself, but the brass looking actuator it is connected to. Kinda sux to replace but it can be done. If the actuator doesn't fix, time to find a "new" LIM. Mazda just doesn't sell the SSV to replace...it's a complete unit.

 

I8u - thats good to know, and i think you are right since when i lightly touch the actuator with my finger, it stops, is this an issue that could cause a problem or is it jsut an ugly noise?


oh and by the way, i have noticed its not just at idle, its just faster and harder to distinguish when you rev, but its still there. do u have that problem? mine is an AT too as i said in an earlier post.

 

^I does cause an issue. Since it is chattering it is not holding the SSV closed at low rpms...which means loss of power up to 4000rpm. Once the reaches 400rpm there is enough vacuum to open the actuator all way giving the power back for the top end. Sux right now for me, I have no power until 4k and then it takes off like a rubber band.

I'm replacing the actuator very soon, found a used one off an old engine.

 

^ holey **** - is that what that is? i have no ***** till like 3500, 4000 rpm - i just thought that's the way it was. i feel like a royal **** right about now.

looks like i'll be searching for an actuator now. are you fixing it yourself? if you do can you put up a DIY?