Popping souind and power loss on acceleration

[Bluedot]

I have an 07 Ms3 (with MS-CAI) and my buddy has a 08.5 (MS-CAI + MS-CBE)

We both have had the same thing occur with our cars and trying to find out what this is.

When accelerating (normally, not racing) in 3rd or 4th gear, typically when getting on a freeway ... the car will suddenly fall on it's face, and there is a rapid popping noise coming from the engine compartment. Take your foot off the gas and keep accelerating and everything is fine.

The first time it happened to me, I thought it was detonation and just quickly took my foot out of it and figured it was the fuel. But it occurred several times after, usually in the same spot while getting on the freeway to work. Listening carefully, it sounds mechanical, like a wastegate or something.

There is never a CEL, and it always cures itself if you back off and then resume acceleration. I've had all the software updates from the dealer, including the check for the fuel pump.

I did ask the dealer and the guy looked sort of perplexed and said if it's not throwing a CEL, who knows ... (sigh)

It doesn't do it every day .. can happen cold or warm (weather). It's just very annoying when it happens. Any help greatly appreciated. If this has been discussed in another thread (I did search) please point me in the right direction.

 

[Bonafide_Spd3]

How many rpms are you at when this happens and in what gear?

 

[Bluedot]

4K RPM (or close) ... usually 3rd or 4th gear

It's not foot-to-floor accelerating, but it's merging on the freeway, so ...

 

[Bonafide_Spd3]

I had a studder when driving in 5th and 6th gear. Rpms ranged from 2500 to 3500 rpm. Someone told me it was boost spike. But I don't know. It isn't the gas I use either because I use 93 octane. I don't have a boost gauge yet so I won't find out til then. Sorry I couldn't help out man

 

[Bluedot]

No prob .. appreciate the thought. (drinks)

Since both of our cars are doing it, figured someone else out there might give me a clue.

 

[aquamar]

Mine 2

I have a '07 ms3 with a Cobb SRI. This happened only once but if freaked me out. I was coming hard out of a turn on one of the great roads of all time.... Highway 25 in central California. I was in 4th gear and hit the accelerator and I got a huge power drop off with popping chattering sound from under the hood.. tried accelerating again right away... same thing.. backed off and it has been fine for the rest of the day. No CEL which is weird.

Mazda probably won't attempt a fix unless they can replicate the problem and experience it first hand or unless it kicks a CEL and they can analyze it. The only way a fix will happen is if everyone who has this problem asks their service manager to contact their service rep to report the problem.

 

[Bluedot]

Thanks for your reply, Since the original post I've talked to yet another Spd3 owner who said they had the same thing happen.

Last time it happened to me was on a long freeway onramp behind some guy towing a 20K lb trailer with an 88' Ford Ranger, by the time we got to merge into traffic (at 25mph) I went to punch it and it fell flat on it's face, rapid popping noise ... lift ... back on and it's fine.

It has to be something. Small part of me wants to wait for it to happen again and leave my foot in it until it breaks, just so I can find out what it is.

Clearly the dealer is "no code? ... then no problem".

I pulled the plugs to look for any signs of detonation, none

If anyone else cares to throw out a clue, would sure be appreciated

 

[dread]

It sounds like boost cut, but there is no way to tell unless you get some data logs. If your boost is spiking above 18psi the wastegate will open and you will lose power. I had this happen a couple of times with my mscai if I floored it without traction. Try going to a different dealer.