6600 is the stock redline on an auto or non-REV 6MT. The rev-limiter may kick in a little above that based on what I've read from other people who hit it, but I haven't ever hit mine in the G.

 

I have experienced this problem sadly it begins with a tick and leads to a rattle and gets louder until power is completely lost. This occurred in my Celica and the result was a thrown rod that resulted in a damaged block, total engine swap was needed. I pray this isn't what happened to you because that set me back a pretty penny. It sucks but this happens when you down shift to red-line like that its a total mistake but an engine fatal one.

 

Valve "tick" and rod "knock" sound completely different.

 

Uh, what your friend did for you is called the "the money shift". It's called that for a very good reason.
It usually happens on MT's but can happen on AT's as well.

How? Well the rev limiter works great when you are up shifting, but it does not work at all when down shifting.

I've seen it a few times at the track. Driver accidentally shifts into first instead of third, and the revs go well into and beyond the redline.

I don't know for sure if you will go above redline when doing 80 mph in 3rd on the G, but if you did, the following things can happen...

Because the pistons travelled faster than the design limits, you may have damaged the pistons, rings, rods, connectors, cylinders, seals, gaskets, valves, etc, etc.

You now know why it's called the money shift.

If you're noticing a loss of power, I would not run your engine anymore until you have it checked and are sure of the cause. Otherwise you could be doing more damage which equals more cost. You could possibly put a piston out the bottom of the engine... I've seen it done and it's not pretty.

Good luck, I hope it's nothing serious. Keep us posted.

 

u really shouldn't be racing and getting head at the same time tho. that's hella dangerous

 

I was simply implying the sounds increased in volume not stating it was two different things.

 

Cracked a ringland is my guess.

Aka you cracked a piston ring. I would take it to a mechanic and get a compression test. My guess is one cylinder or more is down.

 

They have a term for what you did to your G lol

 

That's not possible in a stock auto G unless yours is some kind of fxcked up lol.

 

Given I've never owned an AT but there I would be downright amazed if the computer would let you blow your motor up that way. I'd bring the car to a mechanic who knows Infiniti's before I started to even think about shopping for a new motor.

 

It's not that the computer wouldn't let you, it has no choice. When you drop in to a much lower gear the computer has no say in it. It is what it is. It may cut fuel to the motor, but it can't slow the RPM when it's physically connected to the rear wheels through the transmission. When you accelerate, yes, it will cut fuel when you get the rev limit.

 

That's not true. The TCM controls torque converter lock up and clutch engagements.

It will not allow over rev from downshift, AT is not mechanically connected to driveline like the MT.

I agree with MT the ECM may not be able to cut back ignition preventing over revving on downshift because of the mechanical connection of driveline.

 

I don't know about all this. I've had (or should I say I'm having) the pleasure of owning both the automatic with the manual mode and the 6MT transmission. No matter how I tried, the manual mode in the automatic wouldn't let me down shift to a gear that would cause harm to the tranny. Now, I own a manual transmission and after being out of a manual for about 5 or 6 years I had to get used to the 6 speed gear box. During which time I was down shifting in my 6MT and I missed a gear on down shift and instead of going into 4th, I went into 2nd. The revs jumped to 8000 rpm for about 1-2 seconds at least. I shifted into the appropriate gear and the car is fine. Needless to say since then I've gotten used to my 6MT and my shifts are smooth and clean.

But, when I did have those two miss happs the car was and is fine. I was surprised and in awe to see the revs go to 8000 rpm with no failure. I guess God was on my side. Although, I sometimes wonder if the previous owner did any work to the engines internals because I can shift pass 7000 rpm with no problem (not that I do that often). After my car hits 4000 rpm, it feels like another cylinder has opened up or kicked in. It seems to enjoy being revved at high rpm but, I dare not try my luck and keep doing the 7000 rpm thing. That's just foolish no matter how much the car keeps pulling. As for an automatic dropping down too far a gear. I can't say much because I wasn't there but, from my experience with the auto I owned, it doesn't seem likely. The tranny would only shift down to a gear that would match the revs of the engine and no further.

 

If you keep bumping down the shifter it will not red line on the at. I've pushed the wrong way before and thank god it doesn't jump you down.

 

uh, yeah. what you said is completely incorrect.