Floored it in first and heard a loud BOOM. Think I ran past redline.
WHAT THE HELL WAS THAT NOISE!?

 

When did you hear the boom? When you shifted? Did you hit the rev limiter? Is the car still running okay?

 

Boom like engine or like tranny hitting...

Hows the temp hot or cold... your not running to many mods if i remember correct?

 

sonic boom

 

Was it when you shifted? Probably just a backfire.

 

if you blew something you would know, trust me

As others said, it was probably a sonic boom

 

That was just from the fireworks. Happy new year.

 

It was while I was flooring it in first. I heard and felt it. Sounded like the engine. Its running at normal temps and seems to be fine.

This happened once to me when I floored my bros old C5 past redline. Anyone have any clue what that hell that noise means/is?

 

You can't get the engine past redline with Stock ECU by just accelerating. Our car has a rev limiter. However, if you down shift while redlining in a higher gear. ie redline in 2nd and accidentally hit 1st when trying to get third, then the RPM's can obviously go well over redline.

Can't imagine what the noise would be. A boom sounds like a backfire to me. My Z has never backfired just from accelerating though.

 

What exactly is a backfire? If not during acceleration....then when did you experience it.

 

It could be that if if floored it, especially if you lifted off a bit just before it, that the engine got a bitmore gas then it burned, then when you floored it, the unburnt gas combusted on it's way out.. Um, my non-technical description of a backfire. I'm *sure* someone will correct what I got wrong...

 

Dissident, close enough. I got backfire when my engine was cold and I revved it in neutral. When I let off the gas, RPM's dropped quickly and got a small *bang*. I don't know how loud a boom is, but it sounds like it might be louder than a bang from the way Enthuziast described it.

Enthuziast, if you got a loud bang during WOT acceleration I would check you plugs. If they are fouled that could cause backfire. Do you have any mods on your Z? This would be helpful info.

 

Backfire is the burning or exploding of fuel in the exhuast manifold...makes loud boom and possibly damages the manifold or loose/weak exhaust parts...sounds may be normal for a race car decelerating for a turn...scary for your grocery getter though!

 

You can also get backfire from bouncing off your rev limiter nonstop. I know because the t/a I used to race had an adjustable rev limiter and we would tested to see it's effectiveness.

 

This may be a clue. Were they running out of the bank as you pulled away? If so, that may explain the boom.

OK, in all seriousness, as a mechanical engineer I have to believe that the boom was a backfire that actually accelerated you to supersonic.

Sorry. Really however, do you remember seeing a "do not enter" sign disappear under your front bumper?

OK, I'm out of ideas.......

WayneTN

 

Its probably the rev limiter. Mine cuts the fuel when I hit 6900rpm in manual mode.

 

Im not sure what it was. My car is BONE stock.
But ever since that BOOM I experience grinding when switching from 4th to 5th.

Think these issues are related?
Also does anyone know of a good mechanic at Nissan of Scottsdale?