i_luv_my_rx8

It's been a while since I've posted! Wow.

I did a quick search on the forums to see if this issue had been posted already; I saw a similar post back from 2004, but felt I'd like some more current answers, which is why I am posting it again.

I've noticed that when I'm on the highway going 60-65 mph and I have to slam on my brakes, my car rattles. My car does the same thing when I've slowed down and am creeping slowly towards a stop sign/light. I first became aware of this after getting my tires rotated at the dealer.

It's possible that my rotors are warped, but wouldn't my dealer have mentioned that when they were doing the rotation? My car has only 20k miles on it, so this strikes me as a bit odd... especially since I noticed the rattling only AFTER the tire rotation.

I've gone around to a few mechanics and asked for their opinions. Some say the rotors need replacing, some say the pads need replacing, and another told me that maybe I have a defective tire (meaning it worked fine when it was in the back, but when they rotated it to the front it's malfunctioning). I'm planning to take my car into the dealer later this week to see what they have to say.

Long story short, has anyone here had the same problem and had it resolved? What did it end up being? (I'd like to go into the dealer with SOME inkling of what it could possible be...) The rattling is getting rather annoying... hehe.

Thanks in advance!

slimjimrx8

revival... anyone know wassup? same problem for me but i jus changed the rear pads and it still does it

badandy713

my car seems to do the same thing. i have an 05 rx8 and it only has 23k so far and sometimes when i take off and turn (the wheels isn't turned all the way) a sharp right and even left my car makes a grinding shaking noise in the back. is that normal or is that a bad sign? the other day i had to lay heavy on my brakes and when i took off and drove it for a while it made that same sound. my car also seems to idle rough but i put at least 91 in the tank and it only has 23k. what is the average idle speed for you guys. mine seems to be 8oo rpm (when all warmed up). so is a tune up in order to fix the shaking? i've read online that 04-05 have some bad engine mounts...has anyone had to replace them?

badandy713

to slimjim: one thing i do know is that it isnt the pads and or rotors. ive worked in a tire shop so many times have the wheels on my car been off. the braking system is fine. if your pads or rotors were warped due to heavy breaking and over heating it would vibrate when you slow down. just a slight amount of pressure will let you know. if it vibrates while driving (wheels out of balance, flat spots, alignment wear. etc) but if it get worse then its the brakes. mine seems to do it when im rolling at slow speeds. ive done the alignment on my car 2 times since ive had it. one just a month a go so i know thats fine. i really hope its not the motor mounts and that its just that i need a tune up. same for you slimjim.

Blackout04RX

it sounds like the tires on the rear werent properly balanced before being mounted. Tires shops (most anyway) train their tech not to worry about getting the rear exactly right because the rear tires are not as sensative to out of balance vibrations. When it was rotated to the front, the imperfections are immediately obvious. Take the car back to whoever rotated them, and explain that the wheel balance is off before you give any mechanic your money. Only if it isnt repaired by rebalancing the wheels do you look at the brakes. Start with the cheapest and easiest solutions and work your way back from there

slimjimrx8

yea only problemm with that for me is it just started out of nowhere, my tires werent rotated

slimjimrx8

mine shakes during breaks. Its not that it pulsates where i feel it on my foot as i brake. Its jus i feel the rear shake as i slow down.

badandy713

have you had your alignment checked? not saying that yours might be the same but several straight from factory cars have their alignment out. how is the wear on your tires? any cuping or waving?

slimjimrx8

no cup or waves i checked that and also no uneven tread wear.... low on tread but still even lol

badandy713

how is your brake fluid? did the vibration get any better when the rear was done? and are you still using your stock rims?

slimjimrx8

stock rims and vibration is a tiny bit better after new rear pads but still very tiny improvement

Shane McLain

I have a similar problem but after many miles, I have confirmed that regardless of breaking speeding or coasting, between 52-57 the whole car shakes. I know there are a bunch of different posts for the car shaking but couldn't find one with this specific of a problem. I could be in 3rd 4th 5th or 6th and it will always rattle and shake my entire car as if I was doing 150 down the autobahn. Anyone have any theories as to what could be doing this? The car has 130k so it's no spring chicken but it just started happening out of the blue. The only thing I can think of is the transmission but figured I would ask around here to see what people thought.