Is this sound normal...

[85rx-7gsl-se]

I hear this chugging/pulsing sound. It doesnt really sound like an exhaust leak. Since I am a rx8 noob, figured I would ask the experts.

tu9uc6ver00

[JL1RX7]

All the nipples on the airbox/maf on? SSV in decent shape? Hose off the air pump good?

[85rx-7gsl-se]

I haven't torn into it. Just figured I would make sure it wasn't a normal sound first.

[JL1RX7]

It didn't sound normal. No codes or anything else crazy?

[85rx-7gsl-se]

Only code it had was a rotor 1 misfire. Cleared code and fired it up a few times with no codes coming back.

[JL1RX7]

Still the strange surging sounds?

[85rx-7gsl-se]

Yep. Just picked to car up Saturday. Aside from a somewhat rough idle, seems to run okay.

[JL1RX7]

I would do the normal eight stuff. Change plugs and coils. Check cat, do compression check. Save to rebuild motor.

[reddozen]

These were posted on 8 club about the misfire and rough idle.

Rough Idle PDF:
http://www.rx8club.com/attachments/series-i-trouble-shooting-95/192179d1358693420-urgent-help-rough-idle-cylinder-1-misfire-dtc_enginerunsrough_rollingidle-pdf

Misfire Diagnosis:
http://www.rx8club.com/attachments/series-i-trouble-shooting-95/192175d1358691843-urgent-help-rough-idle-cylinder-1-misfire-dtc_p0301-p0302_1of4-jpg
http://www.rx8club.com/attachments/series-i-trouble-shooting-95/192176d1358691843-urgent-help-rough-idle-cylinder-1-misfire-dtc_p0301-p0302_2of4-jpg
http://www.rx8club.com/attachments/series-i-trouble-shooting-95/192177d1358691843-urgent-help-rough-idle-cylinder-1-misfire-dtc_p0301-p0302_3of2-jpg
http://www.rx8club.com/attachments/series-i-trouble-shooting-95/192178d1358691843-urgent-help-rough-idle-cylinder-1-misfire-dtc_p0301-p0302_4of2-jpg

[djmtsu]

I'm not sure that is the procedure for an RX-8.

The 'official' Mazda dealer procedure is: 'Runs rough or does not start? Replace engine'

Super Cereal

[85rx-7gsl-se]

Well I plan to start off with plugs/wires/coils since no idea when they were last changed. The car starts in about 2 seconds and idles. Previous owner said Mazda told him rotor 1 is dead, but I have a hard time believing that.

I was just wondering what this weird pulsing air noise is.

DJ: shoot my that quote on the coils and I will send $$$.
.

[85rx-7gsl-se]

I would do the normal eight stuff. Change plugs and coils. Check cat, do compression check. Save to rebuild motor.

I have the money for the rebuild already haha. Just want to confirm its low comp before I dump the $$$ into it.

[djmtsu]

Yeah yeah yeah.

[Pete_89T2]

I'm no RX8 expert, but that sounds similar to what a leaking air pump/ACV plumbing sounds like on an FC. Do '8s still have air pumps & ACV's for emissions? If so, give the associated hoses & plumbing a good visual inspection for cracks/leaks.

[FerociousP]

Airpump is electric and only runs during initial startup, and blows directly into exhaust manifold through a (separate from engine) ACV type valve

[85rx-7gsl-se]

Someone on RX8Club said its the SSV arm making that noise.

[reddozen]

That's possible, and it's what I was listening for in your video. I didn't hear the distinctive click/tapping though.

Easy enough to test... when the car is doing it, just reach in and put pressure on the dashpot arm of the SSV valve like you are trying to engage it. I would recommend a catch can if that's your issue. What happens is oil is gunking up the SSV value, and it's coming from the filler post overflow that pumps into the accordion intake pipe. Pretty common problem with the 8. You'll have to take the valve out to clean it, and I would clean the entire intake track to be sure. If that still doesn't work, they're a couple hundred new from Mazda.

I bought one trying to fix mine, but turns out, the problem with mine is the bridge port surging back up the secondary and rocking the valve. I'm just SOL and will forever have a tick.

[85rx-7gsl-se]

Thanks Brian. I will check it soon. However, the sound is more of an air nature than a mechanical sound. As for the catch can, the car already has one. I don't mind the noise, but don't want a vacuum leak.

[reddozen]

Sounds less and less like it's the SSV. It didn't sound like it was to me from the video.

[85rx-7gsl-se]

I would normally guess exhaust leak, but the sound isnt quite what I am used to. May just have to take the manifold off and investigate.