Sudden Acceleration

[Zotaga]

Hey guys, I've developed an issue with my 2006 Mazda3 Sedan in the last couple of days.

When I was at the Timmies drive-thru, my cars RPM shot up and I nearly rear-ended someone.. I thought maybe my foot was half on the brake, half on the gas so I thought it was a mental error but it happened again today and this time I am 100% sure my foot wasn't on the gas/brake at the same time. What could be causing this? Any ideas?

[jay93]

I'm having that same issue

[Nooby31]

Time to sue for $$$$$$$

[m_bisson]

Only in Drive? What about Park, neutral, reverse?

[jay93]

For me it's only in drive

[Zotaga]

Same.

I've only had it happen when I was letting go of the brake slowly.. if I let it off quickly then the RPM doesn't jump.

Talk about a major safety issue.. I can also rule out floor mats because I removed mine awhile back.. so there is nothing there that can be jamming down the accelerator.. :bang


For me it's only in drive

[geobur]

turbo? :P

[Kiewan]

turbo? :P
Because AUTOMATIC.
You should have it looked at if it's a safety issue

[Lux]

Is your A/C compressor turning on?

[jay93]

My compressor is shot so it has nothing to do with that. Plus if I did turn on I'd feel a lose of power?

[Lux]

My compressor is shot so it has nothing to do with that. Plus if I did turn on I'd feel a lose of power?

No, the engine would rev up by ECU command. Plug in a half-decent scan tool and watch the engine load and idle speed control on live data and you will see it yourself.
The engine can rev by command for a multitude of load-compensating reasons.
Imagine trying to accelerate from a standstill while the engine is under high alternator, A/C compressor, and power steering load.
You'd either lug the engine or stall it, unless the ECU commanded a higher idle speed to compensate for the engine load.

[ericssonfan]

I've had the terror of experiencing this twice in my 2007 sedan, both at totally random times over the last couple of years.
One time at a red light where I was very close to rear ending somebody and another time where I was stopped and nobody in front of me.
It was exactly how the OP described it. At first i thought I was on half brake half gas but there was no way. The RPMS shot up to about 3k with a sudden burst of speed very momentarily and the RPM would go back down as quickly as it shot up.

It only happens in drive, never in park. It could possibly happen in neutral; idk cause I rarely ever have my car in neutral.
Crappy thing is that it's totally random and each time its happened, I've left at least one cars length of space at every stop for a whole week afterwards due to paranoia :(

[slam525i]

This had come up before. It happens a lot less now for some unknown reason, but it still does happen, usually in parking lots. Something around once every 5000 to 10,000 km. I'm just glad mine's a manual so it's a non-event. It'd scare the crap out of me in an auto.

http://www.torontomazda3.ca/forum/showthread.php?61592-Sticky-Throttle-Anti-stall&p=906316&viewfull=1#post906316
http://www.torontomazda3.ca/forum/showthread.php?61508-Engine-Rev-While-Braking&p=904887&viewfull=1#post904887

[Kiewan]

Just for clarifying. The rpms shoot up and because its in drive, the car shoots forward as though you were pressing the gas?

[ericssonfan]

Yes, as if you are completely off the brake.
I had to keep my brake pedal fully pressed at every dead stop in case it happened again but it never did. Although I don't think it may have done much with such a burst.

Luckily I wasn't searching my glovebox for something or even texting while it happened.

[Jim94]

Hey guys I have a 2010 Gt sedan and I have had this happen to me multiple times when I step on the clutch and my RPM shots up to 2500 for about 3 seconds

[m_bisson]

Hey guys I have a 2010 Gt sedan and I have had this happen to me multiple times when I step on the clutch and my RPM shots up to 2500 for about 3 seconds

Hmm... Are you getting off the gas immediately before clutching?

[Jim94]

I may have couple times but most of the time if i am running at 3000 and put the cluth in to downshift the rpm goes down slightly and raises again like I am in gear again

[m_bisson]

I may have couple times but most of the time if i am running at 3000 and put the cluth in to downshift the rpm goes down slightly and raises again like I am in gear again

My 06 and 10 both did that. I'm assuming it's normal.

[Zotaga]

It's definitely not "normal" lol.. this is a major safety issue as you could end up killing someone..

Say you were at a red light and a pedestrian was crossing the road and your car all of a sudden shot forward and you ran that person over.. it could be fatal.. what would really suck is if you can't re-create the problem and the cops blame you for careless driving :\


My 06 and 10 both did that. I'm assuming it's normal.

[Jim94]

It's definitely not "normal" lol.. this is a major safety issue as you could end up killing someone..

Say you were at a red light and a pedestrian was crossing the road and your car all of a sudden shot forward and you ran that person over.. it could be fatal.. what would really suck is if you can't re-create the problem and the cops blame you for careless driving :\

For automatic cars yes but for manual its not as big of a deal because you are usually in neutral or you have the clutch in so it wouldnt shoot the car forward but all in all it is a concern for everyone

[davmcn]

my sister's 2012 mazda 3 GS-Sky does this too!

[goodcase]

2010 2.5L manual trans. It happens to me too. I cant replicate it, it just happens.

[jay93]

I think I've come up with a solution to this problem. My last three fill ups in 5 weeks have been with 91 octane by shell. Since then I haven't experienced that problem. I'm going to put 87 in on my next gas stop and see. I'm assuming the 91 cleaned the insides and so far so good

[jay93]

Well, I wanted to post this. Even with the premium gas the car still did this. The car went to the mechanics for brakes and to clear a celo. I'll list what was fixed.
1. Front brakes, pads and rotors.
2. Intake manifold runner replaced. (celo came on saying the runner was stuck open)
3. TB gasket replaced. (I think with this new gasket installed the car has stopped with this sudden acceleration crap when both pedals are not touched AT ALL in drive) hopefully this gasket was the fix to my issue.