2007 Mazda 3 idles high while cold

[Mazda3LA]

I own a 2007 Mazda3 2.0 that idles high while driving cold. I have noticed that within the last three weeks every time the car is cold and I drive in the freeway, the car idles above 3000 RPMs at 60mph until the car warms up. Once the car warms up it goes back to normal RPMs which is a little under 3000. Any suggestions what the issue might be. Took the car in today to the dealer to have them check it out. They did notice that the transmission fluid was a little low. They asked that I leave the car overnight so they can try to re-create the issue in the morning.

Thanks!

Martin

 

[tinmanSC]

Was that 300 or 3000? If I read that correctly at 300, a higher idle when first starting out is perfectly normal. You said trans fluid was low.. This is an Auto? How are you idling down the freeway at 60 mph? I'm confused...

 

[gathermewool]

Do you mean 3,000 RPM? No car is set to idle at 300 RPM, and your car is not idling at all while cruising at 60 MPH. If you mean that your transmission does not down shift until it warms up, then that sounds relatively normal for cold weather. Is it cold there for some reason?

 

[DrDusty86]

300rpms would stall ANY car I've driven. Idles at 300rpms @60mph. Think about what you said. You made no sense

 

[Mazda3LA]

Sorry I meant 3000. The high idling comes while driving in the freeway. i'll step on the gas lightly and that is when the car begins to idle high.

 

[Greggy_D]

Heck.....my 2007 Mazda 3 idles around 750 while warmed up.

 

[tinmanSC]

A 4 cyl idling at 300 would be crazy! haha! My GS300 idels around 450 when warm. I had a 302 V8 from 1973 that I got to idle just above 100. Albeit, somewhat unreliably... and it wasn't running any accessories at the time.

Also, i think you are using the term "idle" incorrectly. Idle = in park or neutral, when the engine is not under any real load (other than, say, the A/C and making power for the radio or something) By idling, do you mean cruising?

Also, you said this was a new thing it's doing? Have you had anything done to the car/noticed anything else?

 

[Mazda3LA]

You're right, I should have used the word cruising. Sorry about that.

I had two motor mounts replaced about a month ago.

 

[tinmanSC]

You don't suppose some sensor got disconnected while they were replacing the motor mount, do you? No check engine light, right?

 

[Mazda3LA]

There is no check engine light on. The issue seems to go away once the engine is warmed up.

 

[chrome]

Automatic transmission? Sounds like the torque converter is not locking up for the first few miles before reaching operating temperature. This is fairly normal behaviour.

 

[Mazda3LA]

Yes it's an automatic transmission.

 

[boosted]

Normal! You should be letting the car warm up anyways before driving especially on the highway. Poor car

 

[PandaBear]

Just throwing ideas out there: clean idle air control valve, mass air temperature / pressure / flow sensor, look for worn thermostat (stuck open which cool the engine down too much when cruise or going down hill), worn coolant temp sensor (happens to my friend's Mazda 3), plugged EGR so too much oxygen during high speed cruising.

Try to clean everything before throwing parts at it.

 

[KrisZ]

Originally Posted By: Mazda3LA
I own a 2007 Mazda3 2.0 that idles high while driving cold. I have noticed that within the last three weeks every time the car is cold and I drive in the freeway, the car idles above 3000 RPMs at 60mph until the car warms up. Once the car warms up it goes back to normal RPMs which is a little under 3000. Any suggestions what the issue might be. Took the car in today to the dealer to have them check it out. They did notice that the transmission fluid was a little low. They asked that I leave the car overnight so they can try to re-create the issue in the morning.

Thanks!

Martin



Roughly 3k RPM at 60mph is normal when the TC is not locked. When the TC locks the RPM drops to around 2.5k at 60mph. Low / used up ATF could cause such behavior.

 

[gathermewool]

Originally Posted By: boosted
Normal! You should be letting the car warm up anyways before driving especially on the highway. Poor car

Idling to warm up will gain you nothing. Start it and drive it, ESPECIALLY if a cold-start is somewhere like San Diego. Start'er up and go.

 

[CharBaby]

Yeah, it sounds like the tranny isn't going into OD/Lockup as soon as it once did, as Mazda3LA has described...And this is just happening to Mazda3LA's car only recently. IDK, check the ATF level HOT and maybe do a D&F with some new ATF. It isn't cold in SD! Also, a TB cleaning with the key out of the ignition and a battery disconnect may help as well. But my 1st guess would be the ATF.
Has anyone been monkey'ing with the throttle/TB by opening & closing the TB with the keys in the ignition(even with the engine off), this will cause some strange things to happen while driving. Strange meaning, different than the way the car/engine/tranny were acting before!!! Could be anything that happens differently!

My daughters '06 Mazda3 2.0 auto here in NY isn't experiencing this symptom as M3LA has described it. It's only in the high 70's low 80's here. And on the first startup of the day on a 60* deg F morning, the tranny goes into OD quite soon. Sure it takes a minute of driving but, it gets to OD quickly.

 

[mechtech2]

Throttle body sticking and idle air control valve are intertwined and should be checked out first.

 

[Mazda3LA]

The dealer looked over the car this morning and noticed that the transmission fluid was a quart low. They added the quart and drove the car with no issues. I will find out tonight whether after work whether the issue has been fixed. Thanks everyone for your comments. I'll let you guys know how it drives tonight.

 

[PandaBear]

Originally Posted By: Char Baby
Yeah, it sounds like the tranny isn't going into OD/Lockup as soon as it once did, as Mazda3LA has described...And this is just happening to Mazda3LA's car only recently.


I know some car (like Ford Escort in 93) use coolant temp to prevent engine from getting into OD, and one of my friend has similar symptom on his Mazda 3's coolant temp sensor. You might want to test / change the sensor and see if it fixes the issue.