My car is shaking and unstable idling when it stop.
 

2004 RX8, 6 manual. 60K...
the car is shaking at red light or stop. idling is slightly mov around at 7-800.
I tought its misfire, So I changed the Cable, spark plug and coil. that didnt really help alot. I thought maybe something about air intake, coz the stock filter was pretty dirty already.
recently, I replaced the dirty stock air filter with K&N. and remove the"devil wall" from inside the airbox. and put a HKS exhaust system.
the car is still shaking. I was wondering whatelse I can do about this.
I went to dealer checked the car at 55K. the engine mount was good. I dono If there is any possible chance I could damage the engine mount within this 5K miles. please give me a clue. what else i should do with it.
thanks guys.

Have you cleaned the MAF?

I am having the same issue right now... I'm going to clean the maf ... lets see....

"devil wall" are you refering to a screen? put that bad boy back in! :lol: if your talking about the vfad then leave it out. You may want to check motor mounts again. 04's are known for the mounts going around 60k. I took mine to a local shop and they looked at my mounts and said they were fine. I took it to mazda and they changed them, no more vibrations. just my thoughts

Motor mounts.... if only my car was more stock!!!!

how to clean the MAF?
thanks.
and I will check my engine mount soon.
where I can get the engine mount?
how much it will cost?

is it a constant vibration or does it come and go in short spurts?

My car kinda does this but I think it's the fan coming on. I hear a LOUD click and the car shakes and the rpms drop and then stops, 5-10 seconds later it starts again and does that all the time when the engine is a temp and idling.

^that def sounds like motor mounts

as for price, im pretty sure its around 200 for the motor mounts

mount can go bad with 22000 miles on the car?

typically no. im not there to sit in your car so im not really sure what is vibrating. Does it vibrate when you are accelerating? or just at idle? with air on or off? or both?

just idle when the car is warmed up. Air On/Off doesn't matter.

when engine is cold, it doesn't do this.

Me thinks it's motor mounts, they do go out and there's not any warning. Really easy replacement. I ordered my mounts from the local dealer and paid 250.16 for both. If you look around though you may find a better deal.

that would be my guess too

how do you know if they are bad though?

your car vibrates LOL

when i am accelerating the car just running prefect. just shaking when I stop the car.

definitely motor mount. just change the passenger side rubber mount. here's a link to buy it. just make sure you pick the right one.

http://www.finishlineperformance.com...cat=338&page=1

can these be installed by normal people with few tools?

probablhy a silly question but maybe this isn't my problem. When I get the vibration, my RPMs drop a bit until it stops then goes back to normal, then repeat until not idling anymore. If it is the motor mount why would that cause the RPM drop?

I seem to have lessened the effects of the shaking some how. I don't know what help but it isn't to violent anymore and it's pretty stable.

The only thing I did recently was I took off those walls in the air box and cleaned out the air filter a bit (I shook it and hit it a few times)

At 22k it's implausible to me to be the motor mounts, especially given the rpm variation at idle. Clean your MAF - get some MAF solvent at Autozone or the like and just spray it in there, rinse repeat and let dry.

I wonder if just taking the MAF out helped. I did remove it to look at it while I was trying to get the airbox off. Now, no part of it looks dirty but I guess it's also hard to see those tiny little bits in there.

Since you gat a K&N... you need to clean it.

The oil from the filter leaves a residue on the MAF.

Also, make sure you have both screens in the tube. Check to make sure it is in there straight.

Rev the engine, if she is moving up its the motor mount.

Get a mate from the club to help you inspect it.

how many mounts are under there?

There be two.

http://www.finishlineperformance.com...cat=338&page=1

btw: see TSB enclosed

motor mounts?