Engine shudders intermittently when idle, should I be concerned? - Mazda3 Forums : The #1 Mazda 3 Forum


FMVPerformance.com is the premier Mazda 3 Forum on the internet. Registered Users do not see the above ads.
Reply
 
Thread Tools
Old 05-04-2011, 11:40 AM   #1
phoenixosu
Grand Am Series
 
Join Date: Aug 2010
Location: Boise, ID
Posts: 373
Default Engine shudders intermittently when idle, should I be concerned?

I have an 09 Mz3 I Sport automatic transmission about 40k miles all stock no upgrades (at least by me, prior owner was a fleet).

The car drives great and has never caused an actual problem but there is some strange behavior when idle that Iíve noticed that Iím not used to (though this is my first car) or havenít seen in any other cars Iíve driven.

Just after coming to a stop at a red light I will hear a faint sound like an electric motor moving something around, I think it is coming from the engine compartment, anyone know what this is?
Also when idle the engine goes through a cycle of being quiet, vibrating a little bit, then shuddering and suddenly going quiet (canít feel anything anymore), it feels like it just stalled out but I know it didnít because the whole thing keeps repeating, I canít notice it when music is playing which is almost all the time. The engine never actually stalls and there is no CEL. It idles at well under 1k RPM.
p.s. also, the RPM needle doesn't seem to move at all when idle, just sits about where I'm guessing it should.

Should I have it looked into or does the description fit closely enough with failures like engine mount of purge valve?

__________________
-Shaun
[size=6pt]Mods: 17x7.5 rims w/ Conti DWS tires | 4 75W kicker speakers | Memphis 300W amp | full size spare | BC Condenser kit w/ extra grounds | CS SRI w/ box | timing advance | upgraded horn | CS LED kit | Axela badge | alu pedals | Momo shift knob | Alu fuel door | footwell LEDs | VTCS delete | TB coolant bypass | L fog light vent | bi-xenon HB/LB | HID fogs | SB LED turn sigs | LED DRLs | LED reverse lights | painted foglight trim | LED tail lights | LED reflectors[/size]
phoenixosu is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-05-2011, 11:01 AM   #2
Reconfigure
Grand Am Series
 
Join Date: Jan 2010
Location: Houston, TX
Posts: 257
Default Re: Engine shudders intermittently when idle, should I be concerned?

Is this with the air conditioner/compressor on? I've heard it will turn on even if the AC light is not on, such as when using defrost.

If not and the idle is steady, I'd say check the spark plugs, but that's just a guess.
__________________
2007 3i MTX
Reconfigure is offline   Reply With Quote
Old 05-05-2011, 11:08 AM   #3
a-sher
F1 Driver
 
Join Date: Jul 2008
Location: lehigh valley, PA
Posts: 3,448
Send a message via AIM to a-sher
Default Re: Engine shudders intermittently when idle, should I be concerned?

Sounds like what my 3 sounds like. Our engines sound weird at idle, I just got used to it. Many get a slight ticking noise. I would check your engine mount, which you can do visually, wouldnt hurt to check your purge eitherr. But if your idles are static and no cels, i wouldnt be overly concerned because from my experience the 3's just sound weird at idle lol.
__________________
a-sher is offline   Reply With Quote
Old 05-05-2011, 07:32 PM   #4
drummr
Short Track Racer
 
Join Date: Apr 2010
Location: Kentucky
Posts: 176
Default Re: Engine shudders intermittently when idle, should I be concerned?

That's exactly what mine does, it's the A/C unit. It gets loud for a little bit, then goes back to quiet, then back to loud, etc. Next time you notice it being loud, turn off the A/C and it will instantly go back to quiet. At least thats how mine is. When the A/C is off, sometimes I can't even tell if the car is on or not it's so quiet.
__________________

2008.5 Mazda 3 GT CWP | CAI | Advanced Timing | TB Ground | Angel Eyes | All Dash/Radio Lights Blue | Eibach Pro Kit | 17x8+42 Gunmetal MB Weapons
drummr is offline   Reply With Quote
Old 05-06-2011, 01:24 AM   #5
ZoominPoet
F1 Driver
 
Join Date: Jan 2004
Location: Waynesboro, PA
Posts: 5,149
Send a message via AIM to ZoominPoet Send a message via Yahoo to ZoominPoet
Default Re: Engine shudders intermittently when idle, should I be concerned?

[quote author=a-sher link=topic=190202.msg4014249#msg4014249 date=1304604514]
Sounds like what my 3 sounds like. Our engines sound weird at idle, I just got used to it. Many get a slight ticking noise. I would check your engine mount, which you can do visually, wouldnt hurt to check your purge eitherr. But if your idles are static and no cels, i wouldnt be overly concerned because from my experience the 3's just sound weird at idle lol.
[/quote]

Being over 100k miles, I've been concerned about our hard idling and sounds while sitting at lights and stuff. Maybe it is nothing and its just the MZ3's nature? Going to have belts and stuff checked at inspection this month.
__________________
ZoominPoet is offline   Reply With Quote
Old 05-06-2011, 10:52 AM   #6
Reconfigure
Grand Am Series
 
Join Date: Jan 2010
Location: Houston, TX
Posts: 257
Default Re: Engine shudders intermittently when idle, should I be concerned?

I wouldn't worry about the noise while the AC is on. I'm pretty sure the clicking whirring is normal.

I was thinking though also if it's idling hard or shuddering you might want to have the timing checked as well if it isn't too expensive.
__________________
2007 3i MTX
Reconfigure is offline   Reply With Quote
Old 05-11-2011, 02:53 PM   #7
mmmm1982
Bicycle Rider
 
Join Date: May 2011
Location: Salt Lake City, UT
Posts: 4
Default Re: Engine shudders intermittently when idle, should I be concerned?

2009 Mazda 3 Sedan 2.0 AT

I've got kinda the same issue: a click and and an electric rotor noise comes from the engine compartment every once in a while. I've investigated it a little bit and found out that it's the unit at the very bottom of the engine (easily accessible from under the car) connected by one of the belts. From what I understand it is the AC compressor. I've noticed this while idling in the parking lot, but I'm pretty sure it's doing the same thing while driving. Why would AC compressor turn on and off intermittently like that even when I'm not using AC?
mmmm1982 is offline   Reply With Quote
Old 05-11-2011, 03:53 PM   #8
Reconfigure
Grand Am Series
 
Join Date: Jan 2010
Location: Houston, TX
Posts: 257
Default Re: Engine shudders intermittently when idle, should I be concerned?

I've heard the compressor comes on even if you don't have the AC on, but only if you have the selector set to "feet only (top center)," or anywhere to the right of that.

If you have a couple of extra minutes, turn the fan on with no AC, and go through the upper/lower/defrost settings and see if you hear the click and whirr sounds. Try it without the fan on as well.
If it doesn't come on in defrost, for example, while the fan is off, you can use that setting to defrost or get outside air flow without using the compressor.

The AC compressor is pretty loud, so you'll notice when it comes on. You might even lose a little acceleration power as well while it's on.
__________________
2007 3i MTX
Reconfigure is offline   Reply With Quote
Old 05-12-2011, 03:06 PM   #9
mmmm1982
Bicycle Rider
 
Join Date: May 2011
Location: Salt Lake City, UT
Posts: 4
Default Re: Engine shudders intermittently when idle, should I be concerned?

Reconfigure
you're absolutely right! I tried playing with the climate control and the AC compressor noise stops as soon as I go past the top center "feet only" mark. Thank you.
mmmm1982 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Mazda3 Forums : The #1 Mazda 3 Forum > Technical / Model / Performance > Powertrain 2004-2009 Mazda3 > Stock Issues

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -4. The time now is 11:12 PM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.