Mazda 3 MPS - Starting problems and rough idle around 740rpm

[Adzy1981]

Hi Guys,

I have a stock Mazda 3 MPS BL series 2 (2009 model). Its just done 66,000 km's and is always regularly serviced at Mazda.

I have just started to have a problem with starting the vehicle when its warm (i.e. - the car has been driven in the previous 20 to 30 mins, and anywhere up to 3 to 5 hours) and also a rough idle when the car is warm.

Problem 1

When starting the engine it now takes a great deal of time to crank the engine (between 3, 4, 5 and even 6 seconds). Mazda advised me that anything upto 10 seconds is acceptable to them (Pffffttttt..... the car used to start within 1 second... everytime until last week). It seems to do it when the engine is warm, and occassionaly when its cold.

Problem 2

Also, once the car is warm I'm having a rough idle issue where the rev's stay around 740 rpm (with air con turned off) and at the muffler it sounds like the engine is missing. Its not an extreme idle issue, but enough to make me feel it inside the car and so very different to what it used to sound like last week.

Please see a little video of the issues I'm having here:


YOUTUBE VIDEO LINK


Mazda service kept my car for 3 days, they said their head tech / mechanic spent a lot of time on it and couldn't come up with an answer to the problem.

There were 2 error codes relating to the battery which he cleared. He tested the battery and it was all okay. It's actually a brand new battery which I just had installed 1 month ago.

Their diagnostics machine came up with no other errors, the engine was firing as it was supposed to, the fuel was tested (I only ever used 98 octane anyways.. shell V or BP ultimate) all okay there.



EDITED **** Mazda have had my car for a week (lucky I have a loan car), they narrowed down the starting problem to a faulty air temp sensor in the MAF sensor (the sensor was not throwing any error's though). They replaced it and now the car start fine.... The rough idle still isn't fixed though. They replaced 4 x spark plugs after noting a mis-fire in cylinder 1 whilst driving the car, they moved spark plugs around and the prblem shifted to another cylinder, replaced 4 x plugs just to be sure..... rough idle still there though. Aparrently they are now wait on Mazda Australia after sending in photo's or the bores.... not sure why they want that but we'll see what happens.****

I'd really love some ideas, or info if any of you have come across this before.


EDITED - FIXED *****************

They also replaced my high pressure fuel pump but it did NOT fix the problem.

They also replaced the EGR valve which finally fixed the starting and rough idle issues for my car. It took a month for that conclusion and fix to be made. Good luck everyone

[lovecolt]

could it be the spark plugs?

[Harry LuvzDrift]

Seems like EGR valve is clogged up. What fuel do u use?

[Adzy1981]

Always Shell V power or BP ultimate

[slixx]

Maybe it's the MAF Sensor

I once cleaned mine and forget to plug it back in and the idle sounded funny.

Maybe it's dirty?

[Pulse_Mps]

My bet is EGR valve. My Gen 1 MPS had similar symptoms and an EGR clean sorted it.

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[SP23HO]

Anyone have a How To for EGR valve cleaning?

[slixx]

Anyone have a How To for EGR valve cleaning?

+1 for me too

[Harry LuvzDrift]

I couldn't be bothered cleaning so blocked it, since then engine runs smooth as.there is HOW TO on YouTube for mazdaspeed 3

[Adzy1981]

I'll check out this EGR valve cleaning video and let you know how it goes. Thanks for the info everyone.

[purenv]

I have a Mps 6 with the exact same problem. I had Mazda look at it and they suggested I sell it, get a replacement engine or get a refurb engine put in. The last 2 options would set me back over 5 grand. I took it to tunehouse for a second opinion and they investigated for two weeks and suggest that it was my spark plug coils. After replacing the coils both problems continued. So they kept investigating. Another 2 weeks later they called me and suggested that the problems exists due to a slack timing chain and some valve problems. So this week they will replace it and check valves and some sensor. Gonna set me back $3300. Ouch but I love my ride so I'm going to get them go a head after all they have spend 4 weeks trying to diagnose the problem. Hopefully I get a fixed car back this week. Been driving the Mrs 99 corolla and missing my turbo. Good luck mate

[Adzy1981]

I have a Mps 6 with the exact same problem. I had Mazda look at it and they suggested I sell it, get a replacement engine or get a refurb engine put in. The last 2 options would set me back over 5 grand. I took it to tunehouse for a second opinion and they investigated for two weeks and suggest that it was my spark plug coils. After replacing the coils both problems continued. So they kept investigating. Another 2 weeks later they called me and suggested that the problems exists due to a slack timing chain and some valve problems. So this week they will replace it and check valves and some sensor. Gonna set me back $3300. Ouch but I love my ride so I'm going to get them go a head after all they have spend 4 weeks trying to diagnose the problem. Hopefully I get a fixed car back this week. Been driving the Mrs 99 corolla and missing my turbo. Good luck mate

OUCH !!! I'm lucky enough to still have a factory warranty until sep 2014. I might have to leave the car with them for a few weeks so they can come to the same conclusion. I hope it's just the EGR valve, but a replacement engine under warranty wouldn't be too bad either.

[Jmac]

I know you said you replaced the battery but... Can you test with another?
Lots of idle issues can be caused by a dud battery.. That and the fact you are having trouble starting it are curious. Plus the fact the ecu had a code for the battery..

Also, I'm in thinking fuel.. Filter/pump?
How does it drive?

Sent from my Nexus 4 using Tapatalk 2

[Adzy1981]

I'm beginning to notice small (and very small) surges while cruising in 4th gear around 3000 rpm. It feels like the acceleration is fluttering up and down ever so slightly. But it's hard to feel unless I'm on a nice smooth road.

[Airsk]

My MPS has the exact same issue. Mazda has had the vehicle numerous times and unable to identify. I get the same old story ' we couldnt replicate the issue' but after having the service manger come out to the car with me when I picked it up it did it in front of him.
So over it, have had many issues with this car and mazda is never proactive and chases repairs up.
Everyone who has this issue needs to make sure their dealer opens a case file so they can see other cars are doing it.

[Adzy1981]

**** Mazda have had my car for a week (lucky I have a loan car), they narrowed down the starting problem to a faulty air temp sensor in the MAF sensor (the sensor was not throwing any error's though). They replaced it and now the car starts fine....

The rough idle still isn't fixed though.
They replaced 4 x spark plugs after noting a mis-fire in cylinder 1 whilst driving the car, they moved spark plugs around and the prblem shifted to another cylinder, replaced 4 x plugs just to be sure..... rough idle still there though. Aparrently they are now wait on Mazda Australia after sending in photo's or the bores.... not sure why they want that but we'll see what happens.****

[KFuNk]

Goodluck to you all!!! Sounds terrible that it can't be identified.

[gotboost]

If you have slack in your belts or even your timing chain it can cause rough idle, or your vvt is slightly worn, I have the same issue but only after a long drive in hot weather, these cars don't like melb traffic that's for sure. Sometimes if I'm in really bad traffic I turn the car off, wait start her up and it seems to go away weird.


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[Airsk]

**** Mazda have had my car for a week (lucky I have a loan car), they narrowed down the starting problem to a faulty air temp sensor in the MAF sensor (the sensor was not throwing any error's though). They replaced it and now the car starts fine....

The rough idle still isn't fixed though.
They replaced 4 x spark plugs after noting a mis-fire in cylinder 1 whilst driving the car, they moved spark plugs around and the prblem shifted to another cylinder, replaced 4 x plugs just to be sure..... rough idle still there though. Aparrently they are now wait on Mazda Australia after sending in photo's or the bores.... not sure why they want that but we'll see what happens.****

How's the starting problem going? Did replacing the MAF sensor completely fix the issue?

My car is in at Mazda all week this time, hope they fix it. Atleast I have a loan car.

[CrImSoNcHiCkEn]

I have recently had my MPS6 lightly modded and 'tuned' (another long story....) This sounded like the problem i was having after the tune, my O2 sensor packed it in and resulted in horrible idle (stalled a couple times at traffic lights). replaced the O2 sensor and seems to be better. The workshop did a check on current being sent to the sensor before replacing it.