Ok I have searched and searched and still haven't come up with anything. My car was just serviced (twice in two weeks). Last week they replaced the clogged cat, and this week was an o2 sensor, MAF, and a new battery. my car is idling lower than when I bought it 3.5 weeks ago (right around 820RPM, judging by the scangauge) and sometimes it will drop to ~700 and i can feel the car shaking. I don't experience any loss of power like so many others do on here, but I am wondering if it could be the coils and/or plugs and/or wires...

Car info:
2007 6spd Sport
20015mi.

Thanks in advance

 

Get the BHR ignition upgrade! I have the same issue. Not to serious. So yea, I would reccomend new coils,plugs/wires(BHR ignition). Check the Ecentric shaft. Go to a rotary performance place to have them check it.

FYI, there are other threads about this. Check the AC compressor as well.

 

Yea I read the other threads but I'm not experiencing any of the other problems so I figured I would double-check...am I hurting the car by driving it around like this? It may be a week or two till I get paid and am able to order the parts...

Thanks

 

Do you have the A/C on when the idle dips down?

 

no it does the same thing with and without the AC on...forgot to mention that in my OP

 

My suggestion is to clean your MAF with a special cleaner you can get at Auto parts store ($7)....if you have origanal plugs, coils, and wires I would suggest you change that...all those parts should be around $270 total

 

Isnt 820 normal? I always thought 750 was the cutoff from abnormal to normal. I have always had it in my head that the car should never dip below 750. I think I got that from nycgps.

 

The MAF is brand new...they just replaced it...I think the general consensus is to check/changed the plugs and coils...thanks

but when it does, the car shakes...and sometimes the car drops into the high 600s...

 

wat up..... So anyway, change your coils,plugs/wires, you can get it done at the dealership but don't be suprised if they charge a lot. I remeber when I went to my mazda dealership and they wanted to charge me $855 to get changed.... WTF. $300 IS OK and you can really DIY(Do it yourself) to save money. If you have the funds, get the BHR ignition(about $480) and send a pm to Charles Hill. Oh yea, don't forget to have the dealership to check the AC compressor because I assume it seems worse with it on. IDK much about the AC compressor though. Your car also probably has a bad missfire. You can kind of feel it.

Change coils/plug wires right away first and then have them check your AC compressor and then get the MAF cleaned and you should have a smooth idle. it's not the other problems, these all contribute to your idle. If one goes bad you notice bad vibration and idling

 

Thanks for all the info The MAF should be clean seeing as they ordered me a brand new one and replaced it. I sent a PM to Charles about the BHR ignition. As I said before, the car runs fine when it's moving...just sitting at a light and idling is where I notice the vibration. I assumed it was a misfire and will be checking the plugs and coils when I get home from work. i don't think its the AC compressor because having the AC on/off doesnt change the intensity of the problem. Could it also just be my ECU re-learning the fuel maps? I just got the car back from the dealer on Wednesday...

 

mine was doing that and it was the engine... new engine runs fine now about 900 rpms all the time...

 

Just a few suggestions here:
If you were blowing enough crap into your cat to clog it then the engine may be carbon fouled. Try Seafoam (plenty of threads here about this procedure). If this helps resolve the problem, next thought is to figure out what was causing all the fouling in the first place: wrong/bad gas, not enough red-lining, probelms with computer maps driving the engine rich or injecting too much oil, etc.

If your MAF was fouled and needed replacement then the throttle body may need cleaning too. Keep going in the air flow channel to the engine and you may want to check the upper intake manifold too.

Try these inexpensive routes and still no fix, then get a compression test done (and properly documented - again plenty of threads on this here too).

Nothing wrong with investing in the coil kit from BHR, its a good mod to think about no matter what, but it won't resolve any of the issues suggested above all by itself.

 

My car was doing same thing, I replaced MAF sensor, new plug wires and ignition coils. Seafoamed the heck out of it. Dealer replaced the secondary shutter valve. Last fall I had already replace spark plugs. Still was stalling at idle, then I cleaned my eccentric sensor and now it runs great. Waiting for some 90 degree days to make sure it is running smooth. Dealer keeps telling me that my compression is good, no problems there. My car hasn't ran this good in over a year.