Not a good day...
 

OK yeah, yesterday I started my day off with my first CEL in the RX8. Of course I freak out and assume the worst. But I checked my fluids the night before and they're all fine so I know thats not it. So I pop my hood with the engine on and nothing sounds or looks weird. But I spot a vaccume line hooked up to my intake hiding under the strut bar and it has to do a pretty good bend so it's a little creased. I look a little closer and it wouldn't be crazy to assume the rubber has cracked. I take it to my friend's dad at Autozone for a trouble-code read just in case.

I pull up into a bay and crawl over (not sure what you call them) but the little lips coming out of the floor to make sure the front wheels stay where they are. He checks it out while I'm looking over his shoulder and yeah the huge 5 word term comes up that basically says a vaccume leak. He clears it and I get back into my car and start it. CEL is gone. I put my car in reverse and try to back out, but when I do I go maybe an inch and the car stops (couldn't get over the little lips) but the back of the car makes this deep shu-u-u-u-dering noise. I'm pretty sure the rear wheels were turning a little but the car wasn't moving. Another guy comes over and says I tried to pull out a little too fast. So we end up just pushing the car off.

On the way home the car feels fine. No power drops, handles great, everything looks good. But then I get off the highway and come to a red light. At the begining of first when I let off the clutch that deep shu-u-u-u-dering sound comes back. It also happens breifly at the begining of second. It keeps happening but the car runs fine. By now I've concluded it definitly is isolated to the back right of the car. Nothing looks out of place but there's so much shit under there I can't really see anything laying on the ground underneath it. I bust out my old college suspension books and all they say about the kind of sounds the car is making is exhaust flange damage. The car didn't bottom out so I don't know what to think. I really don't wanna take my car to the local Mazda dealership cuz I know from experience they're horrible and I know if I just turn my car over to them and ask to find whats wrong they're going to keep my car for 2 weeks and then tell me I need a diff replacement for $10,000.

So yeah anyone know whats up with my car? It only makes the sound when its fully warmed up, at the begining of 1st and 2nd till about 2,000 rpm, and when I stopped by work for some paperwork I got back in my car 30 seconds later and it made the sound while idling! Any help would really be appreciated =(

You're still under warranty so take it in and have the dealer diagnose the problem.

exactly. as long as you're under warranty then you have nothing to worry about.

Thats what I told myself. Its my only car though and I'm worried the only thing the dealer is going to recomend is them keeping it there for a weekend or whatever to find the source. Also I'm pretty much broke (maybe $100) and my next paycheck goes to paying for the car. Just worried about them charging for a diagnosis or a deductable or whatever. OK, if nobody can give me at least something to go by I'll stop by the dealer tomorrow. Just don't wanna go in and say 'OK...here's my car...call me when you find something...'. Last time I went to them it took them 5 weeks to get me some plastic splash guard pins. Never called me like they kept promising I always had to call them and get on their ass about where my stuff was. God knows how long it would have taken if I didn't. I just have no faith or trust in them and it would amaze me if they diagnosed the real problem the first time. Oh well. In about 24 hours I'll be turning down allignments and air filter lubrication for my oil-free filter...

if it's a warranty issue they can not charge you a diagnosis fee, period. if it's not warranty, you're at their mercy. they should also give you a loaner car while your warranty issues are being resolved free of charge.

are you still under the bumper-bumper and powertrain warranty?

should still be yep. coming up on 37K miles.

Absolutely hectic day. Couldn't take my car to the dealer cuz so much shit happened and I now know that the shuddering is actually a rattling sound still coming from the bottom back right of the car. Its much louder on the inside of the car than the outside, and causes vibrations I can feel through the arm-rest. Also my car was idling like hell today (no doubt due to the vaccume leak) but still. Ugh. I really don't wanna admit defeat and say the RX8 isn't a reliable car. I'm going to the dealer no matter what tomorrow. I'll pass judgement then. I hope my 8 is ok =(