Xyxtyx

Hello, everyone.

I have a slight issue with my 8. I've tried searching, but the number of threads about TOB rattle and secondary air pump noise simply overshadow any thread where I could find any relevant information - I'm positive it's neither of those two problems.

The screeching/scratching noise I'm worried about is coming from under the car, somewhere in the middle (right behind the drivers seat, lets say) and can be heard only when the car is started cold - it then goes away after cca 15 seconds. If the car is warm/hot when starting, the sound is nowhere to be heard. The car herself runs perfectly smooth, the sound just makes for an awkward start - it's quite loud if you're standing outside the car.

My first thought was a loose exhaust pipe, but that turned out not to be the case.

Has anyone run into a problem like this and could share what the issue was? Or at least point me in the right direction on where to continue looking for causes.

NotAPreppie

Are you absolutely certain that it's coming from behind the driver? Have you popped the hood and had somebody else start the car while you listen for noises?

What have you done to rule out the SAIP?

I ask because I can't think of an item that far back that would only make that noise for a few seconds and only runs when cold.

I suppose it could be a heat shield that's gotten bent but only makes contact when it has contracted while cold. Have you had a look underneath to check that?

Xyxtyx

It might be right under the drivers seat (a bit more to the front than said before), but definitely not anywhere near the front end of the car.

I tried what you said, letting someone else start the car with the hood up. The engine compartment only makes the zoom zoom noise of the engine, with the occasional relay click and whatnot other misc - the said scratching noise isn't coming from there.

I went out again to try to locate the precise location of the sound just a while ago. And while I don't have a lift to lift the car, just putting my head under the the car, where the drivers seat is, leaves me sure the sound is coming from somewhere there. The sound is also louder on the drivers side than it is on the passengers side.

Supposedly it would be smart to find a lift somewhere and take a look underneath the car to see if anything is loose.

EDIT:

I disconnected the SAIP and the noise was still there. Also, in the past I already had a faulty pump, so I'm somewhat familiar with the sound a faulty secondary air pump makes.

NotAPreppie

Man, I just can't think of anything in the area of the driver's seat that would make a noise like that in those conditions...

Reoze

Just to get it out of the way. You keep saying drivers side, but is this a LHD or RHD RX8? Also is it an AT or MT?

Could you try getting a recording of the noise?

Xyxtyx

It's a 2004 6 speed manual. And it's a LHD car. Completely stock. I'll try to make a recording of the noise in question tomorrow and upload it.

Thanks for the help so far, guys. Much appreciated.

Xyxtyx

Ok, made a recording of the sound. Since it was a cold morning it's quite noticeable this time around (usually it's not as pronounced). Sorry for the bad quality, my phone isn't the brightest of the bunch.

Right after starting the cold car: Vocaroo | Voice message

For comparison, after a few minutes of idle: Vocaroo | Voice message

Both are recording with me sitting in the drivers seat, open door with my hand stretched out and down.

Jarrell Williams

iTrader: (1)

Have not had this issue. My suggestion would be to jack the car up (use jack stands so you do not die), and have someone start the car while you're under it. Do it one morning when you're off or something. From listening to the clip, I'd say its a possibility that its coming from the trans. I know our transmissions are generally loud when they're not in gear (by design). If it is coming from your trans, how does your fluid look? Ever change it?

Xyxtyx

Fluid has been changed less than a year ago (red line) and should be fine.

Reoze

Complete shot in the dark, but any chance it's the starter failing to disengage? It seems like the noise corresponds to the engine RPM. Could explain why it's louder on the drivers side.

Xyxtyx

Definitely worth checking out. She still has the original starter and I have had the uprated one ready for install for months now, so if that's the case it'll be an easy fix. I'll check it out and report back what I find. Thanks!

Xyxtyx

Since I'm having my starter replaced next week, I've decided to take the time and replace the clutch too (even if it's not the source of the issue here, it's still pretty banged up already).

So I have another question for you guys. I'm not looking for an expensive clutch, I'm just looking for something to tie me up for the next 2, maybe 3, years. I've been searching around the web and found these:

OEM CLUTCH KIT 2004-2011 MAZDA RX8 1.3L

ACS MEGA STAGE 2 CLUTCH KIT 2004-2011 MAZDA RX-8 RX8 ALL MODELS | eBay

I'm leaning more on the side of the OEM one, but I'm a bit confused as how come an OEM part would be so cheap. Seeing how my official dealer would charge me 630$ for the OEM part.

The car is a weekend driver, so it doesn't really get high mileage, that's the reason why I just need a clutch for cheaps to keep me tied up for a few years - planning a complete rebuild at that time.

Any insight would be much appreciated.

Reoze

That's not an OEM clutch. A more accurate description might be "OEM style clutch". Generally unless you're pushing a lot more torque to the wheels an OEM clutch is the best option.

with that said, doing this while replacing the starter doesn't save you any time or money. The procedures for those things are only similar in the aspect of involvin the bell housing. Beyond that they couldn't be more different.

unless your clutch is completely toast, I'd skip it.

Xyxtyx

So, being an "oem style clutch," it should do for a while? I'm sure the actual oem is better quality, but like I said, I'm planing on rebuild in the near future.

And yes, I am aware these two procedures don't really complement each other. But since I just found out my clutch is actually still original (13 years old) and since I'll have the car at the mechanic, I might as well replace it now. It's not completely toast, but it's definitely getting there. I'll, of course, have my transmission checked first to see if the transmission itself is toast and the cause of the screeching.

I guess I'm taking this opportunity to softly fix up some of the underlying issues the car has. Since it's not my daily driver, I can afford to get a few things sorted.

Thanks!

Reoze

With the clutch being the definition of a wear item and the cost to replace it ($500-800) you generally don't do it in a preventative manner.

I wouldnt touch that ebay clutch with a 10 foot pole either. You would be better off buying an aftermarket one.

Replace the starter, it shouldn't cost more than $50-100 and an hour of time if you already have the parts. jumping from that to clutch replacement is stretching it a bit.

Xyxtyx

I'm not really well versed in clutch lore, but how long does a clutch last in a car like the 8? Seeing how the car is 13 years old and still has the original clutch, wouldn't it be smart to just replace it before it explodes on me?

What are any good aftermarket clutches? Browsing ebay.. there seems to be many. Even Exedy ones come in so many different flavours, but the stage 1 organic is already one the expensive side of things.

NotAPreppie

It depends entirely on how well you drive stick.

Some last well over 100k and others die in 1/10th of that.

Xyxtyx

A few days later, clutch replaced (old one was definitely slipping hard), replaced starter and thorough check of the undercarriage for any loose parts... The screeching is still there. Mazda all but gave up on it, saying if the car runs, it runs.

Could there be something terrible wrong INSIDE the actual transmission to make such weird sounds? Alas, the transmission has been working flawlessly since the oil change not long ago.

It's driving me nuts.

Reoze

If you press the clutch in, you're essentially disconnecting the flywheel from the transmission. If it's still making the same noise, then I would look elsewhere. It's possible it could be one of the parts for the clutch, but considering it was just replaced that is doubtful.

Mazda gave up on it? Did they try to find the actual source of the noise? It doesn't seem like it would be that hard to do with it up in the air.

NotAPreppie

Agreed.

If the sounds go away when you're stationary with the clutch disengaging the gearbox from the engine, I don't see how it could be the gearbox.

Time to get a set of four sturdy jack stands and get the car up in the air. Start it and then crawl underneath. Order of operations is important here. It's unlikely that anything will cause the car to fall on you but, if it does, it will be most likely when you start it or somebody climbs in/out.

Xyxtyx

The sound itself, from cold start, is the same no matter the clutch position or anything, so yes, I doubt it it's connected to the transmission in any way.

I drove the car to my friend's place who has a car lift (really not keen on lifting the car on stands and crawling under it - no experience equals fear of squishness) and we took a look under it. Now I imagine why Mazda gave up on it so quickly. The car has to be dead cold for the sound to make its appearance. We left the car over night, turned it on and started looking. Alas, the sound went away before we even had the chance to remotely locate it. Shutting it off and back on again... I suppose it was already warm enough to start "silently."

With the car turned on, but the screeching gone, we continued to look for anything off place. The exhaust system is rock solid, zero give, everything that's supposed to be bolted is bolted in place and so on. Nothing is loose whatsoever. The new clutch and starter are also working as intended - it turned on nice before, but now it's like a magic trick.

​​​Left the car on the lift again, going back tomorrow to try again. If we don't locate it tomorrow, I'll just take it back to a different Mazda service for them to have another look.

More and more I'm thinking it's just some tiny little piece of metal hanging from somewhere hidden and that it's nothing serious. But it's still annoying and I would very much like to fix it.

Thanks again for putting up with me and for all the help, you guys are truly the best.


P.S.

The air pump, which can make somewhat similar noise (but in a different place) has been disconnected through this entire process, so it's definitely not it.