Brand new Mazda 3 - rough idle

[blondee_yvr]

I am proud to say (I think) to be a brand new Mazda3 owner. I decided to get a 2.0 auto since I drive mostly in the city and driving a stick didn't make much sense for me.

Anyhow, right away, as soon as I pulled the M3 off the lot and I came to a red light, I felt a slight rough idle, it is very slight, but noticable to me. The car also does this when the engine is fully warm, only when the car is at a stop and the engine is in gear. I hadn't noticed it doing this in Neutral while stopped.

I called the dealer up and he said to let the car break-in, but I wonder if this rough idle will disappear after the M3 is broken in. I am thinking perhaps the MAF or 02 sensor is a bit flaky or even the computer is compensating for the mixture or timing.

Any ideas?

Thanks

 

[goldwing2000]

Definitely wait for the break-in. The motor doesn't really know what it's doing yet because the computer hasn't had much of a chance to learn anything.

It sounds like you have the auto trans, so there will always be a little bit of vibe at idle in gear because the rpms are so low. It will definitely minimize over time, though.

 

[RedRaptor]

When I first got my car (2.3L Auto) I had the same issue. When I was stopped at traffic lights, I felt the rough idle also. It went away at about 2500km. My first oil change was at 3000km. I haven't had the rough idle issue since then. I'm at 7600km now.

 

[mazdaspeedpower]

My moms 05 Mazda 3 GT sedan still has the rough idle at 5600km...she's already had her maintenence, and nothing really changed. Should I get her to tell them to check it out? She says she doesn't notice it, but man, I get in there, and boy do I feel it...it's like, how do you not notice this rough idle.

 

[blondee_yvr]

My moms 05 Mazda 3 GT sedan still has the rough idle at 5600km...she's already had her maintenence, and nothing really changed. Should I get her to tell them to check it out? She says she doesn't notice it, but man, I get in there, and boy do I feel it...it's like, how do you not notice this rough idle.

Definitely...it doesn't hurt to take it into the dealer. I know I will if the idle doesn't improve. I will let my engine break-in before I will do anything. Kinda reminds me of driving an old car with a carb. It almost sounds like there is a firmware issue with the computer if all these 05's have this issue. If that's the case, that's an easy fix. If it is flaky parts, well that's a different story.

Good to know that at least I am not alone in this one. (canada)

 

[sound wave]

my car is at 460 miles right now and it also idles roughly. on another forum they were stating that a possible cause could be a faulty purge control valve.

i guess i will follow your advice and wait until the car has had a chance to fully break in before i take it in to the dealer.

edit: oh, i didnt realize this was my first post on this forum.

 

[blondee_yvr]

It sounds like you have the auto trans, so there will always be a little bit of vibe at idle in gear because the rpms are so low. It will definitely minimize over time, though.

Really?? Of all the fuel injected auto tranny's I have ever had, I never had any issues with rough idling.

 

[timt]

Fuel Pump?

Not sure if its related, but there is a known issue with the fuel pump. My '04 3 was slow cold starting. They replaced the pump and I think there is a service bulletin on it. Good luck.

 

[blondee_yvr]

Not sure if its related, but there is a known issue with the fuel pump. My '04 3 was slow cold starting. They replaced the pump and I think there is a service bulletin on it. Good luck.

Good tip. What do u mean by "slow cold starting"?

 

[chrisyoung10]

ground your throttle body i did it and it makes the engine idle at a lower RPM and it is not a rough.

 

[RonH]

My atx ldles so smooth, I have to check the tach to see if it's still running. Take it to the dealer, but make sure it idles rough before you try to explain the problem.

 

[Gambino]

I also have a grounded throttle body and a perfectly smooth idle

 

[blondee_yvr]

I also have a grounded throttle body and a perfectly smooth idle

Interesting....but you shouldn't have to ground the TB. To those that grounded it, was it idling rough before the grounding?

Yeah, I will take it in to the dealer, but I haven't had a chance yet. Any recommendations of a good Mazda service dealer in the Greater Vancouver Area?

 

[blondee_yvr]

Ok, dunno if this is related but I am still using the A/C and the rough idle is much much worse with the A/C on.

Any how, I have an alarm installed and the other night, while I was sitting inside my car listening to the stereo I noticed the Alarm's LED or idiot light was flashing brighter and lighter to the beat of the stereo. The ignition key was in the ACC position.

Me thinks there are some commonalities here. Perhaps a poor ground or insufficient voltage, or ??

 

[deepfriedsushi]

A friend of mine has an 03 mazda3 5 door and is experiencing similar problems, but to a greater and more dangerous degree.

While driving or while waiting for a light the engine would rev irradically by a couple hundred rpm, to the point where if its at idle while coasting/waiting, it would stall the engine.

He's taken it to the dealership twice, and they told him that nothing is wrong, yet the problem still comes up every so often.

He said the problem goes away if he revs the engine at a high rpm for several seconds, and happens mostly during the first drive of the day.

He parks the car outside, but this is California weather, so there's not much of an issue there, although moisture could be forming inside?

I'm very concerned about this, cuz the dealer said nothing was wrong, twice...Maybe a visit to a different dealer is in order.

 

[blondee_yvr]

I'm very concerned about this, cuz the dealer said nothing was wrong, twice...Maybe a visit to a different dealer is in order.

I dont think taking it to a different dealer will make a bit of difference. They all hook-it up to their diagnositic computer and if there are no error codes and it performs withIN spec they say that nothing is wrong.

One dealer I spoke to said that grounding the throttle body makes no difference.

Maybe one day there will be a TSB on this, maybe not.

 

[deepfriedsushi]

The first time this happened was a while back, probably like at the beginning of last summer (2004)? It doesn't happen very frequently, but its a problem that comes up here and there.

How do we find out TSB's?

Just out of curiosity, what was the mazda5 recalled for? i heard something about the engine and its fuel system.

 

[goldwing2000]

How do we find out TSB's?

Search, Grasshopper... search!
http://www.msprotege.com/forum/showthread.php?t=106250

 

[dread]

here are the tsb's
http://www.finishlineperformance.com/mazda3/bulletins_index.html
Maybe its your motor mount that causes vibration

 

[deepfriedsushi]

here are the tsb's
http://www.finishlineperformance.com/mazda3/bulletins_index.html
Maybe its your motor mount that causes vibration

Thx! I guess those lil problems just weren't for my friend's 3.

I don't think it would be a motor mount, cuz it doesn't happen all the time, and its not really a vibration, its the engine revving irradically to the point of stalling WHILE DRIVING.

edit: After lookin at the tsb's on http://www.finishlineperformance.com/mazda3/bulletins_index.html

it seems like it could be the 4th problem?
"MIL Illumination, P0171 / P0172 / P0441 / P0442 / P0455 / P0456 / P2177 / P2178/ P2187 / P2188"

That seems like a problem that would cause rpms to jump around so randomly.
I've played with gas RC cars before, and i remember having to "tune" them all the time to get the rite mixture.