Getting hesitation/shaking when car warms up - Please Help!
 

Hi all:

So I did multiple searches on different scenarios and I am at a loss as to what the issue is.

I am getting a slight hestitation/shaking or 'misfire' at low rpm's when I give it gas in Park/Neutral or start from a stop. This usually happens when the car is hot and/or when it is warm outside. My car is Auto so i can't tell if it would happen in any other gear but it definitely happens from a stop and when I give it some gas in park/neutral. Its actually getting to be quite annoying.

The car has approx 35k miles and I just did the plugs last week and it is still happening. I have a couple of assumptions but want to see what you guys think first before I go ahead and spend more money.

Any help is appreciated in advance,

Thanks

ken

I'm getting the same vibrations on my car as well.

I took it into the dealership and there was a TSB for a broken motor mount. I believe the cause was extreme exposure to heat. They're ordering a new motor mount with revisions from Mazda under warranty.

You may want to check this as well.

wow - great suggestion. I was honestly thinking its my ignition coils, etc.

i'll make an appointment...though my car is out of warranty, this might be in the extended engine and drivetrain warranty.

thanks!

Here is the "TSB"...is your car in that range?

http://www.finishlineperformance.com...01-09-2062.pdf

You need a tune up.

Car runs pig rich. Plugs are fouled and misfiring.

commomn with RX8

Thanks for the suggestions. Reading the TSB posted by the members above, the symptons are exactly that.

I just did the plugs last week and the problem still exists. Only other thing i could think of is the coils and spark plug wires.

If its a TSB, will they cover it, even though its out of warranty?

You have an '05 and they base the warranty from the date the car began its warranty. I have an '05 as well with 23k miles on it, but the car was never registered until '06.....therefore I have about 10 months of warranty left on it. You might want to check the same for yourself.

As the others said. Have the dealer check the motor mounts first if under warranty. That will definitely cause shaking during idle. Especially if the idle is rough. I would still plan on changing the coils. They don't last much more than 35K. If you have a rough idle, meaning it moves a lot and is inconsistent then changing your coils will probably fix that.

I just called Mazda and they said that regardless of when the warranty expires, it is void now, b/c this car was purchased originall in Canada (my wifes car). That being said, I am screwed under Mazda.

But reading your comments above...can it just be my coils? The car doesn't really shake/shudder at idle. Its more when I accelerate from a stop in D or give it some gas in P/N.

I'm confused now.

It still sounds like motor mounts to me.

They're really not that hard to replace. Put car on jackstands, get another jack (with a 2x4 piece of wood and some rags).....jack up the motor from the oil pan, you'll see the motor lift up a bit. Then undo the bolts, take out the old mounts and it's brackets, and reverse all the steps.

I would say motor mounts (if it's your first time) should take about 1-2 hours.