2006 Mazda 3 idle problems

DAMONFUNG

MEMBER
2006 MAZDA 3
1.5L
4 CYL
2WD
AUTOMATIC
200,000 MILES

Hello I recently bought this car so I do not have any history of it. The car is a Right hand drive Mazda 3 with 1500cc ZY engine but I am hoping you will still have common problems like the left hand drive models. Also this one has Electronic throttle body

Without any A/C and the car is in park or neutral it idles at about 700RPM which is fairly ok I think.
However, if u put it in drive and hold on the brakes like at a stoplight for instance then the idle drops to like 500RPM after about 5 seconds. At this point the car starts to vibrate which I figure is from the engine shuddering under the low RPM

If u put on the A/C it raises the RPM back up to 700 but as the A/C cycles and cuts off then it will drop back to 500RPM.

So can u please advise what is causing the idle to drop to 500RPM when the stopping at stoplights and car is still in drive? There are no error codes showing up when scanned using a OBDii and also the engine check light never came on.

Thanks
Damon

8 Replies

MHPAUTOS

MECHANIC
31,937 POSTS

I would be checking for a faulty idle control air valve first, start here.

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Wednesday, November 19th, 2014 AT 2:32 AM

DAMONFUNG

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5 POSTS

Hello thanks for the reply. Where is the idle air valve located? No error codes are shown when the car is scanned with the OBDii and also no engine check light.

Should I also try to clean the throttle body?

Thanks
Damon

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Friday, November 21st, 2014 AT 4:23 AM

MHPAUTOS

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Not a version sold in the US, may be the same as Aust Version I will have a look for some relevant info

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Friday, November 21st, 2014 AT 2:58 PM

DAMONFUNG

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5 POSTS

Hi Thanks a lot will look forward to your reply.

In the meanwhile I will try to clean the throttle body. I see quite a few mazda forums for the US version mazda 3 that has the same problem and the solution seems to have been cleaning the throttle body.

I also saw one that says this is normal for the RPM to drop to 500 and is called sub idle to save gas.

I drove a Nissan Sylphy today (the US is called Altima) and the RPM also dropped from 750 to 500 at a stoplight but the idle was still smooth and no vibations so I am wondering. This car also has electronic throttle.

I also drove a Scion XA that has the manual cable throttle and this RPM does not drop at a stoplight

I also drove the older MAzda 3 that has the cable throttle and this RPM also does not drop at a stoplight

So in light of this I am now wondering if it is only electronic throttle that does this.

Looking forward to hearing from you about the location of the idle air valve. For your US version Mazda 3 Is it normally on the air intake manifold next to the throttle body or is it at the back of the engine near the firewall? Please send me a pic of where your own is.

Damon

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Friday, November 21st, 2014 AT 6:33 PM

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