Here's one that's stumping me. I've never heard my engine ping before, but I would swear it has started pinging in 2nd gear, low RPM, low load, no boost. I'm hearing a rattling type noise coming from the center of the dash that sounds like it's in the engine bay. You can only hear it with the windows up. But the crazy thing is that it TOTALLY goes away in any other gear. The ECU isn't making any decisions based on gear is it? I'm totally stumped and can't figure out anything other than the transmission that could make a noise based on gear, but it doesn't sound at all like it's coming from the tranny. Any ideas at all????

Can't wait for my PFC to arrive. At least then I could know for sure if it's pinging or just a rattle.

 

It's not knock but some other noise, it's very hard to get knock at very light load. Not sure how you think the Power FC is gonna tell you if it's knock?

Wade

 

I thought the PFC would let you monitor the knock sensor, so I would be able to see if it's reading differently in 2nd. Of course I guess there's a chance that whatever's rattling would show up on the sensor too.

Glad to hear it shouldn't be knock, then. But I'm still stumped. Any speculation at all what would just rattle in second from the engine bay? It's completely gone at all load levels and rpms in other gears.

 

hey, i hear some kind of a noise coming out of the center of the dash at 1st and 2nd gear and low rpms. as soon as my rpms cross 4000 or i put it into third the noise goes away. i wouldnt classify it as a ping though (and i am 100% sure its not knock). i have also noticed that on hotter days, the noise is more loud and noticeable than cool days.

 

Not that this is your problem, but I had the exact same thing. The noise sounded like it was coming from behind the dash. It also only happened at the lower RPMs, when the car would shake more....

It was my shift ****.. lol... Tightened it up and the noise was gone.

 

What do you guys mean by pinging?

 

umm...just a word of caution, go have it checked out! my car is dead because of this rattling noise at low rpms. My noise is not gear-dependent however.

The front rotor is dead. We have not pulled the engine yet so we don't know what caused it.

David

 

Interesting replies. After deciding maybe it's not a ping, I got up enough nerve to get into the gas more, and it seemed to quit from that too. Everything in the car rattles, so it's probably just something loose and it's hitting the right frequency at that point. I'll just wait until it falls off and then it'll be obvious...

As far as taking it somewhere, that really doesn't seem to be an option. I'm not letting my local Mazduh boys get a hold of it!!! (just bought a clutch switch there, which took forever to get them to understand, and noticed a FD has been parked in their service garage for over a month now....nothing should take that long!) I would be more afraid of it being knock if it weren't gear specific.

On the other hand it's no telling how long it's been doing this. My radio just broke, so it's not on, and my windows are usually down, so I probably just never heard it before!

 

Mine sounds like it pings at idle sometimes, but it's that mysterious noise from inside the dash...probably just something loose vibrating at a specific rpm/frequency.

K