Hey guys quick question. I noticed that my rx8 runs smooth when the engine is cold, but as it heats up it starts to shake more. I just replaced wires coils and plugs thinking this would fix but now im thinking is this just natural for a rotary engine to shake. Please let me know for if something is wrong I dont wanna drive it

 

cold = higher idle rpm
the lower the rpm the shaky the engine gets.

 

hmmm motor mounts?

 

we need more information. heres fill in the blanks.

year
model
miles
auto or standard
last oil change
cel codes
after market mods
last coil/plug/wire change
type of oil used
previous mech history issues
have you inspected the motor mounts
was the ac running
how long have you had the car, since what mileage
last engine replacement if ever

theres a few just to start

 

Are you talking about the shifter moving?
That's normal.

 

^thats what she said^

 

year 2005
model gt
km over 80,000km
Standard
last oil change one month
cel codes dont know what this means???
after market intake by injen sp6080
last coil/plug/wire change yesterday
oil used now because of summer time 5w30
type of oil used: Quaker non synthetic
Previous Mech issues cat was replaced at 40,000 (this is when I didnt have the car) and 80,000 ( When I bought the car), starter changed, thats it
I have not inspected the motor mounts
Ac not running
Iv had the car for 4 months, at that time it had 71,000km on it
Engine has not been replaced

As for where the engine vibrated...yes shifter but i know thats normal but I also feel it in my pedals especially we stopped and I just have my foot on the break its vibration. Dont know if its normal. Its just when the engine heats up more it vibrates a little more then when its cold. If it were the mounts i would think it would be vibrating the same no matter what the engine temp is. Anyways thanks for your help and hope to hear from you guys soon.

 

cel codes dont know what this means??? It means "Check Engine light". I'll assume you don't have one being illuminated.

after market intake by injen sp6080. suspect, but read further......ignore this comment for now.

last coil/plug/wire change yesterday so here is my guess before we go any further. If it was fine before, then car is probably re-learning the fuel trims.

Personally, I would do the 20 brake pedal stomp.
1.) Turn the car to "on" but do not start.
2.) Tap on the brake pedal pretty quickly(about 20 times) until you see the oil gauge needle sweep all the way one direction and then sweep back.
3.) Turn car off.

If gauge doesn't sweep, then after a few seconds of rest time, repeat 1-3 until it does.

Now............having said that, please note that it might take a couple of drive cycles for it to settle down after doing this. It might even try to stall on you the first time or two you come to a stop and try to let it idle.

If after a few drive cycles, you are still shaking more than you think you should, then I'd start looking at cleaning the MAF and/or motor mounts.


That's my two cents.

 

what does the 20 break pedal stomp do?

 

resets the KAM

 

Hey thanks for your help. Ill give it a shot but just for the record since im new to the whole car stuff can someone please tell me what MAF means and KAM because i would like to understand exactly what im doing.

 

MAF (Mass Air Flow)- Measures air flow in the intake.
KAM (Keep Alive Memory)- Performed by disconnecting the battery to clear things like fuel trims.

Mazurfer mentioned the "20 brake pedal stomp"... that is the NVRAM.
NVRAM (Non Volatile Random Access Memory)- Memorizes the profile of the eccentric shaft plate on the e-shaft pulley

 

oops i switched them

 

^..........Newb.....hey wait, didn't you catch me in a mistake the other day? If you did............then touché

Oh yeah..........I remember, it was in that thread about a girls automatic and weird acceleration issue when I said it could be the clutch slipping!

 

Thats not the case, alot of us notice rough idle when the rpms drom down to about 1000 or less but when it is just being started, the idle is higher and makes the idle smoother. Worst cases of the rough idle are due to many different factors. I would definitely check the motor mounts first, than clean the MAF, the other issues are ignition related which shouldnt be your problem unless you got a bad coil out of the box or something. You may just have one issue or a couple. Call for a quote ( it wont hurt)

 

maybe the motor mounts combined with the car relearning the fuel trims

 

when talking about iddling, whats the normal rpm for iddle when the car is warm? like after driving 10 or 40 minutes and your waiting at a light? my car iddles at around 750-900 is that normal? my car also shakes a bit . Like you need to pay attention and know the car to it to feel it ( my girlfriend never noticed it ), is not bad at all but and hard to tell its shaking is that normal?. and here are the details

year 2004
model gt
miles 74 000 kms or around 43 000 miles
auto or standard of course standand
last oil change 2 months ago
cel codes no never
after market mods aem cold air intake
last coil/plug/wire change no clue. Im replacing plugs in the next 5 days
type of oil used 5w 20 mineral
previous mech history issues recalls and all that before i bought the car
have you inspected the motor mounts no
was the ac running no
how long have you had the car, since what mileage 4 months and 65 000 kms
last engine replacement if eve never

Thanks a lot for the help

 

Honestly doesnt sound like too big a concern but the idle shouldnt fluctuate too much. O.K, i just read that you have an aftermarket intake. That can be a huge source of the issue. Double check your connections. Did you install it yourself? Did you use at least one mesh screen? A Blurb from RACING BEAT to read about mesh screens

the stock air box (two screens) and the Racing Beat REVi Intake (1 screen) both have about .005 volt "scatter" – natural fluctuations with time. By contrast, another popular aftermarket intake kit (with no screens) has roughly .050 volt scatter – 10 times as much! – which causes idle instability and possible engine stalling.

 

george, once you replace the coils inspect the motor mounts, let go of the shifter, and check your vibrations at 1000rpm.

 

thanks for the replies guys. I have the AEM cold air intake and yea my friend and me installed. All the connections are right and it has 2 screens on it. And sorry when i said 750-900 my car actually iddles steady i just dont know what rpm it is it could be 800 and its a 100% steady. And ill check the mounts as soon as i get a bit of free time

thanks again

 

i recently had the same problem with the car shaking real bad when i would come in to a stop. the rpms would drop very low and it would shake real bad. mazda said the motor mounts were bad and are going to be replaced. i hope that solves the problem

 

i got my motor mounts swapped today. rides smoother

 

What should one expect to pay for new motor mounts?

 

Bout this or cheaper.

http://www.finishlineperformance.com...ction=0&page=2 depending on where.

 

just for the parts, about 250-300 dollars. You can find them at 100 dollars and 150 dollars on average for each mount. The two different mounts are priced very differently.

as for installation, well just get a group of guys from you area to help you