Idle goes up and down
- Thread starter P5 Fan
- Start date
shane02pro5
25ish_psi
- :
- New Caney TX
Egr needs cleaning...stuck opened from build-up causing a vac leak ??
booboo0809
Member
- :
- P5
if u look into cleaning it there is a how to forum on removing and such but it doesn't always fix the problem, so be ready to take it into a shop afterwards if its a no go! cleaning did work for me for about 100k then it started acting up again so i got it fixed. GL!
I have had 2 new EGR's in 2 and a half years of owning my MP5.First time it was replaced it did in fact need replacing, the second time was by Mazda, but turned out i needed new coil packs and now i have just get P400 codes which cat related( That dealership will never see another red cent from me as long as i own this car). I experience similar idle problems to this day, every time i go home from work and i get off the highway , first red light i hit i can see my RPMs going up and down. Are you getting any codes?
booboo0809
Member
- :
- P5
that sucks... gotta love the stealerships! any luck yet with the funny idle??
shopkins73
Member
- :
- 03 protege5
i have the same problem, can someoen tell me where i can locate the egr?pics?
CheeseHelmet
Member
Here you go: http://www.mazdas247.com/forum/showthread.php?94788-How-To-EGR-Removal-and-Cleaning-Rough-Idle-Fix
It's a rather annoying job (tight space to work) but quite doable, I just cleaned my EGR for the 3rd time last week and it only took about 30-45min.
booboo0809
Member
- :
- P5
^ agree!!
super tedious but u can do it... if i remember right, u have to get into an awkward position with the wrench but after that smooth sailing... until u have to put it back on of course! that thread above is perfect and has great directions! if u have time to waste i would try soaking it in cleaner for the best outcome?? i did it with a tiny toothbrush and q-tips and it was a little annoying, but i did get a hell lot of gunk out of there! GL!!
super tedious but u can do it... if i remember right, u have to get into an awkward position with the wrench but after that smooth sailing... until u have to put it back on of course! that thread above is perfect and has great directions! if u have time to waste i would try soaking it in cleaner for the best outcome?? i did it with a tiny toothbrush and q-tips and it was a little annoying, but i did get a hell lot of gunk out of there! GL!!
Alternately, the air intake boot might be ripped, creating a vacuum leak: a faulty EGR and vaccuum leak cause similar symptoms.
1. ripped air intake boot: rough idle that stays rough
2. faulty EGR: when coming to a stop the idle drops to almost stalling, if the EGR unsticks the idle can become normal again
Both should cause codes.
1. ripped air intake boot: rough idle that stays rough
2. faulty EGR: when coming to a stop the idle drops to almost stalling, if the EGR unsticks the idle can become normal again
Both should cause codes.
is it really creating a vac leak? i thought if the valve was stuck open i would recirculate too much burned gaz and that woudl be why the engine would almost stall, because it cant burn burned gaz.
^correct. Not a vacuum issue.
yes, the engine will stumble at idle if the exhaust gas is mixed in. The EGR ensures it only opens at highway speeds (to reduce cylinder temps from running leaner for emmisions).
Vacuum leaks are evident by a idle that cycles up and down (as the ECU tries to compensate). Faulty EGR just stumbles/low idle.
yes, the engine will stumble at idle if the exhaust gas is mixed in. The EGR ensures it only opens at highway speeds (to reduce cylinder temps from running leaner for emmisions).
Vacuum leaks are evident by a idle that cycles up and down (as the ECU tries to compensate). Faulty EGR just stumbles/low idle.
shane02pro5
25ish_psi
- :
- New Caney TX
If the valve is gunked up not allowing the valve to close fully and seal how is it not allowing unmetered air to enter into the im from the exhaust when your sitting at idle or any time in vac or losing meterered air in boost?
Just putting it out there, but couldn't it also be the IAC valve? Might be totally off, but I'm having similar issue and I'm definitely getting the EGR replaced as it has shown up during other issues, but have been wondering if the IAC might also contribute to the problem...
Boston5761
Member
- :
- 03' Familia
could this also be caused by the timing being off?
CheeseHelmet
Member
Nah, the car would run like s*** in that case, he's just suffering from crappy idle.
Boston5761
Member
- :
- 03' Familia
actually read a couple of threads with people experiencing the same problem(s). turned out to be the intake cam timing being advanced
How the hell does that happen?
