Stock MS3 detonating....bad

[drago86]

So about a month and a half ago when it was hotter in my area, my car had bad detonation at least 5 separate times. I first suspected the gas station I was using, but it still happened after trying different stations (91 of course). All of the times but once it was when I was at ~70 mph, a little less then 3k rpm in 6th gear and floored the car to pass someone. The other time it happened right after I shifted into third or 4th (don't remember exactly) after pulling out of a toll both at wot shifting the previous gears at ~6k. It was defiantly bad detonation, the whole car bogged and it sounded like little gnomes wee bagging on the engine with ball-peen hammers. I lifted immediately each time but it still worries me. It was also completely unpredictable, as I would do the exact same things that would cause it to detonate previous and it was normally fine.

I took it into Mazda the first chance I could, but they said that they wouldn't do anything unless they could duplicate the problem. It had cooled off by then and with it being so intermittent in the first place i was unable to make it happen on the drive with the tech so they didn't do anything.

The car is bone stock, oil has always been changed by the dealer and it has only ever seen 91 octane gas.

Any ideas?

[danesti]

a lot have experienced this. try not to put load on the car under 3k.
people have stretched the ignition coils and had positive results from it (http://forum.mazda6club.com/index.php?showtopic=90286)
as for now downshift and roll easier onto the throttle.

or this one
How To: Spark Plug Replacement - Mazda6 / Atenza

[drago86]

How is poor ignition causing detonation? It seems sort of weird for this to be common, if everyone's car does this below 3k there should be a lot of failures eventually.

[toprock]

Stretching out the coils in your coil packs helps it have more solid contact when it lights, thus helping you reduce cylinder misfire.

[darth vader]

really, this car likes alot higher than 91 octane fuel, to be honest, especially when it gets hot. it's alot of static compression and boost.

[drago86]

It's not missfire, it's knock for sure.

And I can't get anything higher than 91 in CA,..

[ungrave]

Welcome to the club. This is one of the problems mazda has yet to fix.
And the worst part is, it's probably connected to the part throttle zoom zoom boom issue IMO....