Over-rev a LS7?

[johnm]

Can anyone tell me if I hurt my engine or if I am being paranoid. I was out celebrating the passing of the 500 mi break-in period the other day and was going through a hard launch (not a wide open throttle launch but close) when I missed 3rd gear. The motor revved pretty high, but I don't think it reach 7000rpm but it might have for just an instant. The motor made a funny noise at that point then every thing seemed ok. Since then when I drive the car I think I hear noises I haven't heard before. For instance I hear what sounds like a faint spark knock on hard acceleration that I don't remember being there before. It might have been I just don't remember it. I also thought I could hear a faint knock on Idle when standing outside of the car. yesterday when shut the car off I could definetely smell a faint burning odor. when I checked under the hood I could see nothing out of order.I know these cars are pretty noisey to start with so I hope I am just being paranoid. sorry about the length of this thread.

 

[warren s]

I would venture to guess that you did absolutely no damage at all. The rev limiter would keep you from over revving the engine. I bet the LS family of engines could sustain operation at the red line for hours.

 

[Hib Halverson]

On a missed upshift you're probably ok as the rev limiter will prevent any serious over-rev however on a wrong downshift, ie: you wanted third but got first, you'll break the motor unless you have really quick reactions and can catch it before it revs too high.

"Faint" detonation on hard acceleration should be more like momentary knock as the knock sensors detect detonation and the engine controller retards spark to stop the detonation. At high load you should not hear detonation lasting more than a fraction of a second, no matter if it's faint or otherwise. If you do hear detonation, there's a problem somewhere.

 

[zachh]

I agree with Warren S, I work on brand new ones, they can do things youd be surprised at. We had a truck at our shop the owner wanted the engine replace (sucked up a little bit of water, bent a few rods and it had a 100 thousand miles on it) It was an LS1, we drained the oil out and had it running with no oil for over 4 hours, bouncing it off the revlimiter the whole time. The funny noise you heard when you missed 3rd probally was you hitting the rev limiter, they have a 7000rpm max. The noises when it starts (pingin) are normal(GM says to expect them)
best wishes
zachh

 

[johnm]

Thanks for all the help boys. Makes me feel a lot better.

 

[DRTH VTR]

I have hit the rev limiter on my C5 Z06 MANY times. It does sound kind of funny when it happens, but there is no harm done.

 

[Rowdy1]

Cheap Insurance.............

The absolute best guard in over revving an engine is a rev limiter. My "old" 62 has a solid lifter 327 with some other work done and I have a chip I can change out in about 30 seconds to any RPM I desire. I run a 7,000 most of the time, I actually ran an 8,000 for a while. Miss a gear with hydraulics, no big deal, miss one with solids, "Rut Ro". I use the after market MSD 6AL box which not only gives you a little extra spark but the luxury of changing your limiter to what ever you want in almost any increment.

 

[Warp 10]

3 more cents worth

Ditto on damage,

With LSX engines, you will almost always hear ticking noise from the injectors. Also normal but a little irritating when compared to a Lexus 460.

Enjoy your great ride and just ignore the petty distractions!

 

[johnm]

On a missed upshift you're probably ok as the rev limiter will prevent any serious over-rev however on a wrong downshift, ie: you wanted third but got first, you'll break the motor unless you have really quick reactions and can catch it before it revs too high.

"Faint" detonation on hard acceleration should be more like momentary knock as the knock sensors detect detonation and the engine controller retards spark to stop the detonation. At high load you should not hear detonation lasting more than a fraction of a second, no matter if it's faint or otherwise. If you do hear detonation, there's a problem somewhere.

Is there any non invasive way to check it out.If there is a problem can I make it worseby ignoring it and keep driving.?

 

[agentf1]

You are being paranoid, your motor is fine.

 

[DRTH VTR]

The Z06 is a street legal racing machine. It is very robust. You did not hurt your car. I have about 200 runs down the drag strip and many weekends of autocross on mine, and it is just fine. The rev limiter is there to prevent damage, which is just what it did.

 

[catbert]

CHECK YOUR ROCKER ARMS!!!!!!

 

[TODD L GRIFFITH]

Check the oil filter and or the rear end diff fluid for small metal fragments. Probably is fine, but fear of the unknown always makes one uneasy lol!

 

[Ken Olson]

Hey, saw your thing about the rev limiter....I've got a new Z06, love it, but i frankly don't know crap about the newer engines. They actually have a limiter to stop at 7000RPM?

Love the car, but saw some needle bearings on the magnet, first oil change, 6000mi. Haven't had it looked at yet,but got my fingers crossed.

Ken

 

[catbert]

7000 is no problem for the LS7. Tuners place the rev limiter at 7500.