Blubeasty22

When my 8 idles, I can hear a tapping sound under the plastic intake manifold. It seems to be in the area where the plastic manifold ties into the metal portion of the manifold. The tap is a regular tap-tap-tap-tap in sync with the idle. It disappears as you climb out of idle. The problem hasn't increased after showing up and doesn't affect the idle at all. The sound can be heard inside the cabin.

I'm tempted to take the manifold off to inspect it, but I don't know if the sound is coming from the manifold itself for from a component beneath it and on top of the block.

Thoughts? Thanks

LittleZ360

If it is indeed from the manifold, I'd be guessing it's SSV related.
You say your going to take the manifold off to inspect, I'm assuming you're referring to the Upper intake manifold. The SSV is lower, which is easy to test with a quick search on here.
However, if you plan on removing the UIM, I believe you can get a view down into the valve ports and watch the valves as you move them manually. I'm not sure how much that will tell you though.
When I hear ticking noises I always bust out the stethoscope. Why waste time removing parts when you can track it down with your ears?
Also, if you want to remove to whole intake manifold, you're going to have to drop the engine out as well... Bit too much work for just an inspection. Run to autozone and get a stethoscope... or get crafty and create your own!

jkstill

Any more ideas on this?

Anyone know if this is a known problem on the RX-8?

Mine just started making the same ticking noise described.

It is a base model 2006 with 6500 (yes, 6500 miles) so wear and tear should not be an issue.

I have a fair bit of experience with RX-7's, but not too much with the RX-8, and this is not a noise I expect from a rotary.