rev limiter - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

24Mark · 08-06-2010, 07:56 PM

Does the LS3 ECM prevent you from over revving the motor by cutting the throttle?

I am having an issue with my car and the chevy dealer says the engine was over revved to over 9000 rpm and they will not cover it under warranty.

I am pretty sure I didn't over rev it but the ECM is reporting that in the diagnostic according to the dealer.

PLEASE HELP!

DSteck · 08-06-2010, 11:10 PM

Throttle and spark cut, yes.

It's still possible for an engine to get over-revved if you miss a shift... like hitting 1st instead of 3rd.

24Mark · 08-07-2010, 03:11 AM

Thanks

traderfjp · 08-07-2010, 11:32 AM

I would think that even if u missed a shift the rev limiter would still cut the throttle.

camaro1 · 08-07-2010, 12:27 PM

Quote:

Originally Posted by traderfjp

I would think that even if u missed a shift the rev limiter would still cut the throttle.

yes, but if you hit 1st instead of 3rd or2nd instead of 4th you will still over rev the engine, no matter if the throttle is closed or not

Capthowdy · 08-07-2010, 12:45 PM

9,000 holy shit batman those are indy numbers....

Slowhawk · 08-07-2010, 02:08 PM

If you hold the gas to the floor it can easilly go to 9k rpm. The rev limiter cut's spark/fuel but DOES NOT stop the car from overrevving. Pretty much says - hew stupid,let off the gas.

The most common is listed above. overreving from back shifting. 7500rpm is high enough to float the stock valve/spring combo and do damage.

DSteck · 08-07-2010, 03:15 PM

Quote:

Originally Posted by traderfjp

I would think that even if u missed a shift the rev limiter would still cut the throttle.

Mechanically forcing the engine will over-ride the limiter.

Quote:

Originally Posted by Slowhawk

If you hold the gas to the floor it can easilly go to 9k rpm. The rev limiter cut's spark/fuel but DOES NOT stop the car from overrevving. Pretty much says - hew stupid,let off the gas.

The most common is listed above. overreving from back shifting. 7500rpm is high enough to float the stock valve/spring combo and do damage.

There is no way you can just free rev it to 9000rpm. The rev limiter kicks in pretty hard. As soon as power is cut, the engine can't continuing accelerating.

24Mark · 08-07-2010, 05:43 PM

It was definitely over revved, the dealer showed me the valve impact marks on at least two cylinders. They only had one head pulled but ECM shows a miss fire on one cylinder on other bank so probably on that one too.

They did admit computer couldn't tell exactly what RPMs were but they were high. My 20 year old son admitted to taking it out while I was out of town and while accelerating at around 70, passing a car, he went from 3rd and missed 4th and hit 2nd. That will do it.

Still don't know if I have bent rods, definitely bent valves. Should know Monday. This is going to be one expensive joy ride for my son!

Slowhawk · 08-07-2010, 07:13 PM

If the valves hit the pistons good the rods should be changed since it can tweak them.It would not show till you put good miles on it.

And yes,you can over rev the piss out of it. Put the car in 1st gear and hold the gas to the floor going down the street.These newer cars with low power won't over rev too much but it will go past 7k rpm. I'm use to higher hp blower cars which can blow right past the rev limiters.

DSteck · 08-07-2010, 10:07 PM

My 630hp LS7 will not go past 7200. As soon as it touches 7200, it shuts down hard. Unless the PCM has been screwed up and somebody messed with the intrusiveness of the limiter, a stock limiter won't let you spin the thing that high.

tony1 · 08-13-2010, 07:48 AM

Iam no mechanic but it sounds like what your saying it wasn't from stepping on the gas to have it rev that high it was from some serious down shifting that your 20yrd old was doing... I sure if you go totally nuts with it you'll end up breaking something... I'd make my 20yr old work and pay me back every penny. You spent alot of money on this car to have him disrespect it that way.

Hylton · 08-13-2010, 08:32 AM

Quote:

Originally Posted by DSteck

My 630hp LS7 will not go past 7200. As soon as it touches 7200, it shuts down hard. Unless the PCM has been screwed up and somebody messed with the intrusiveness of the limiter, a stock limiter won't let you spin the thing that high.

I wish my LS3 would cut out at 7200....

Torrian · 08-13-2010, 08:44 AM

My ss is at the dealer right now because of a bent valve and they said it was not coverd but i got a call thursday and they said they would cover all the cost i only have 7,400 miles on it.

08-06-2010, 07:56 PM	#1
24Mark Drives: '10 Camaro 2SS RS IOM Join Date: Jul 2009 Location: Anchorage, Alaska Posts: 8	rev limiter Does the LS3 ECM prevent you from over revving the motor by cutting the throttle? I am having an issue with my car and the chevy dealer says the engine was over revved to over 9000 rpm and they will not cover it under warranty. I am pretty sure I didn't over rev it but the ECM is reporting that in the diagnostic according to the dealer. PLEASE HELP! __________________ 2SS/RS IOM exterior; IO interior accents; polished wheels; black rally stripes 1100 = Preliminary Order: 7-27-09 3000 = Accepted By Production Control:8-10-09 3100 = Sequenced: 3300 = Scheduled For Production: 8-10-09 3400 = Broadcast: 8-10-09 3800 = Produced: 8-12-09 2G1FT1EWXA9135426 4000 = Available to ship: 4200 = Shipped: 8-13-09 5000 = Delivered To Dealer: 8-31-09 6000 = Delivered To Customer:9-4-09

08-07-2010, 03:11 AM	#3
24Mark Drives: '10 Camaro 2SS RS IOM Join Date: Jul 2009 Location: Anchorage, Alaska Posts: 8	Thanks __________________ 2SS/RS IOM exterior; IO interior accents; polished wheels; black rally stripes 1100 = Preliminary Order: 7-27-09 3000 = Accepted By Production Control:8-10-09 3100 = Sequenced: 3300 = Scheduled For Production: 8-10-09 3400 = Broadcast: 8-10-09 3800 = Produced: 8-12-09 2G1FT1EWXA9135426 4000 = Available to ship: 4200 = Shipped: 8-13-09 5000 = Delivered To Dealer: 8-31-09 6000 = Delivered To Customer:9-4-09

08-07-2010, 05:43 PM	#9
24Mark Drives: '10 Camaro 2SS RS IOM Join Date: Jul 2009 Location: Anchorage, Alaska Posts: 8	It was definitely over revved, the dealer showed me the valve impact marks on at least two cylinders. They only had one head pulled but ECM shows a miss fire on one cylinder on other bank so probably on that one too. They did admit computer couldn't tell exactly what RPMs were but they were high. My 20 year old son admitted to taking it out while I was out of town and while accelerating at around 70, passing a car, he went from 3rd and missed 4th and hit 2nd. That will do it. Still don't know if I have bent rods, definitely bent valves. Should know Monday. This is going to be one expensive joy ride for my son! __________________ 2SS/RS IOM exterior; IO interior accents; polished wheels; black rally stripes 1100 = Preliminary Order: 7-27-09 3000 = Accepted By Production Control:8-10-09 3100 = Sequenced: 3300 = Scheduled For Production: 8-10-09 3400 = Broadcast: 8-10-09 3800 = Produced: 8-12-09 2G1FT1EWXA9135426 4000 = Available to ship: 4200 = Shipped: 8-13-09 5000 = Delivered To Dealer: 8-31-09 6000 = Delivered To Customer:9-4-09

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08-06-2010, 11:10 PM	#2
DSteck Account Suspended Drives: 2006 Corvette Z06 Join Date: Feb 2010 Location: St. Louis, MO Posts: 587	Throttle and spark cut, yes. It's still possible for an engine to get over-revved if you miss a shift... like hitting 1st instead of 3rd.

08-07-2010, 11:32 AM	#4
traderfjp Drives: Audi A4 Join Date: Jul 2010 Location: Smithtown Posts: 49	I would think that even if u missed a shift the rev limiter would still cut the throttle.

08-07-2010, 12:45 PM	#6
Capthowdy Drives: 2010 2SS RS IOM Join Date: Jun 2010 Location: Fort Lauderdale Fl Posts: 1,048	9,000 holy shit batman those are indy numbers....

08-07-2010, 02:08 PM	#7
Slowhawk Drives: 1999 Trans Am Join Date: Jul 2009 Location: Bridgewater,Ma Posts: 2,017	If you hold the gas to the floor it can easilly go to 9k rpm. The rev limiter cut's spark/fuel but DOES NOT stop the car from overrevving. Pretty much says - hew stupid,let off the gas. The most common is listed above. overreving from back shifting. 7500rpm is high enough to float the stock valve/spring combo and do damage.

08-07-2010, 07:13 PM	#10
Slowhawk Drives: 1999 Trans Am Join Date: Jul 2009 Location: Bridgewater,Ma Posts: 2,017	If the valves hit the pistons good the rods should be changed since it can tweak them.It would not show till you put good miles on it. And yes,you can over rev the piss out of it. Put the car in 1st gear and hold the gas to the floor going down the street.These newer cars with low power won't over rev too much but it will go past 7k rpm. I'm use to higher hp blower cars which can blow right past the rev limiters.

08-07-2010, 10:07 PM	#11
DSteck Account Suspended Drives: 2006 Corvette Z06 Join Date: Feb 2010 Location: St. Louis, MO Posts: 587	My 630hp LS7 will not go past 7200. As soon as it touches 7200, it shuts down hard. Unless the PCM has been screwed up and somebody messed with the intrusiveness of the limiter, a stock limiter won't let you spin the thing that high.

08-13-2010, 07:48 AM	#12
tony1 Drives: 2SS/RS Vortech/L99 Join Date: Jan 2010 Location: CHICAGO Posts: 474	Iam no mechanic but it sounds like what your saying it wasn't from stepping on the gas to have it rev that high it was from some serious down shifting that your 20yrd old was doing... I sure if you go totally nuts with it you'll end up breaking something... I'd make my 20yr old work and pay me back every penny. You spent alot of money on this car to have him disrespect it that way.

08-13-2010, 08:44 AM	#14
Torrian T$'s SS Drives: Victoryred with black rally stripes Join Date: Feb 2010 Location: Atlanta Ga Posts: 11 View My Garage	My ss is at the dealer right now because of a bent valve and they said it was not coverd but i got a call thursday and they said they would cover all the cost i only have 7,400 miles on it.