Hey S2KI,

I own a 2007 AP2 with 52,000 miles on it. A short while over a month or so ago the car seemed to idle rough but it wasn't very consistent and wasn't bad enough for me to make much concern about it. After a while I drove the car more frequently and the car's idle is really rough. It idle's at about 750 rpm and it's almost as if the car is pulsating. I don't drive the car everyday for I have other vehicles which is why it took so long for me to notice it. The check engine light is also not on and I just took the car in and got all the belts, oil, etc checked just before this happened. I was wondering if you guys had any idea what could be the issue. The car seems to have close to the same if not the same amount of power it did before this started happening. The best way I could describe it though is that it doesn't feel as finely tuned as it did before and it's almost like there is a leak of power somewhere. Any suggestions would be greatly appreciated, thanks!

- Matt

 

What weight oil are you running?

You'll notice compared to a luxury car or even a standard sedan the motor in the S is 'raw' and rather unrefined at idle. This can make idle seem rough.

 

I'm not sure what weight oil I am running. A dealer has done the oil since the car was purchased at 4,000 miles. The thing is, the car never idled this rough. It always seemed more smooth. Also, when I turn the air-conditioning on, the car will go through this cycle where it almost stalls out at a stop, and the sensors will kick the rpm back up to about 1500 and it will drop to low, to about 500 and almost stall again and it will jump it back up and do that over and over. Still no check engine light. Pretty sure that isn't normal.

 

If you're looking for helpful ideas, you'll probably find more people with mechanical knowledge in Under the Hood.

If you're looking for a mechanic to take it to, the regional forums are the place to go.

I'll guess your problem is MAP related, but that's just a total guess on my part. GL w/ the car.

 

Thanks for the help, appreciate it

 

Shoot us some video. If it's just a rough idle, but car doesn't shake and you can 'feel' a cycle in the motor it's probably normal. Remember it's just a 4 cyl so you will feel the firing.

 

If oil level is fine, my vote goes towards your valves just needing tightening.

 

Thanks for the suggestion guys, I'll take a video and mention the valve tightening to my uncle. My uncle used to build motors back in the good ol' days and he has been trying to help me troubleshoot it. I'll video, put it up on here, talk to him, and then take further steps. Thanks!

 

So I have a video to upload. I just took my Mazda 3 in to my uncles mechanic and it just started having the same trouble (rough idle) and they found out that I had two broken motor mounts and my spark plugs weren't working fully. I am guessing that I may have a, several, or loose or broken motor mounts.

Hmm... Facebook won't let me upload the video.. How should I go about uploading the video?

 

youtube.... ?