I definitely think it's the transmission now. To me it sounds like gears are slipping causing the noise and vibration which would also explain the RPM jumps with no power. Then they catch and all is well. It seems the noise is closer to you than an engine issue would be, on my laptop's poor speakers it sounds like something's vibrating right under the floor of the car.

But I'm not an expert and members like cleric have vastly more technical knowledge than I do so I'll stay subscribed to this thread bcuz I'm curious what it turns out to be. I can honestly say that after owning my G for 9 years I've never heard of another G or Z have an issue like what you're going through and over the years I have known/know several hundred G and Z owners..

 

Thanks for the input. Yeah I couldn’t find ANYONE who had this issue whether it was a Z or a G. I will say that I did have a transmission issue back in ‘14. Had a solenoid replaced but all was good after that. I’ll take it to a reputable mechanic on an off day and see if that is the case. If it is then unfortunately that’ll be the end of my 6 years with her. Not worth doing that job on a car this old with low value. Hurts my heart saying it.

 

Lol that is wild. I can't even think of anything on the car that sounds like that. It almost doesn't sound metalic enough to be gears..but it does sound like some fluttering gears.

Hmm..do you have a baseball card in your spokes?

 

It doesn’t sound as metallic. Not since I swapped out the diff bushings. It’s just weird man.

I’ll double check on the spokes lol.

 

Oh, Snap, that's kind of the same chatter (but more violent) that comes from the ABS a little after you start the car. Wonder if it could be an ABS issue in the rear.

When's the last time you changed youe brake fluid?

 

 

Wow that sounds absolutely terrible... If it wasn't for the rpm flutter I'd say to check the front bolts on the plastic engine bay cover under the vehicle it sounds like something flapping in the wind and slapping the car really hard.

I think youre going to need to take this to a shop asap for a diagnosis before it Kabooms and leaves you stuck on the road.

 

 

Does anyone know if the pan bolts are reusable? The FSM says it's not but there's no part number listed for the bolts when looking online.

 

Wow that's funny it DOES say to not reuse transmission bolts, probably the same sort of thing as it saying not to reuse the intake manifold bolts. It's a cheap insurance policy for the dealership against anything potentially happening to the transmission, they have deniability against fastener problems because they used new bolts. I would definitely reuse them without a second though.

 

Maybe apply some blue threadlocker to prevent it from leaking?

 

Nahh the bolts aren't going to leak, you will be using permatex ultra grey on the pan gasket though.

 

Not the oem gasket? 31397-90X00

 

Ohhh sorry, I forgot that pan had a gasket.