: Engine damage while downshifting 2-1 at the redline


mkturtle
03-27-2007, 02:40 PM
Hi all,

I accidentally shifted back to 1st while at the redline in 2nd....(or it might have been 3rd to 2nd - due to shock I can't remember for sure).
I felt car jerk, tires chirp and my OE shift light went on at which moment I hit the clutch.
I kept driving for about 15 minutes after this and did not notice any weird noises.

How do I know if I caused any damage? Or, am I going to see problems some time later due to the stress I put on components during this event????

Please advise.

Thanks.

MK

zachd
03-27-2007, 02:47 PM
my only suggestion is learn how to drive a manual in something other than a 30k car.

im sure the car will be fine, just learn how to drive, thats all :D

PitchBlackGTO
03-27-2007, 02:54 PM
my only suggestion is learn how to drive a manual in something other than a 30k car.

im sure the car will be fine, just learn how to drive, thats all :D

That's pretty harsh zach! We've all done it. You're probably ok if you hit the clutch right after. You'd probably know if ya smacked a valve.

Brazen6.0
03-27-2007, 02:57 PM
I was reading about that after I used the search button about "ticking noise".

zachd
03-27-2007, 02:59 PM
That's pretty harsh zach! We've all done it. You're probably ok if you hit the clutch right after. You'd probably know if ya smacked a valve.


i had to say it!!! otherwise someone else would have beaten me to it!!

i have done the same thing once or twice from 3rd to 2nd instead of 3rd to 4th while street racing. i would also say your fine as long as u got the clutch back in right away.

mkturtle
03-27-2007, 03:11 PM
I was testing this OE shift light.... I don't think its my driving skills.... I think this shifter wasn't design well.

Yes - I hit the clutch when the shift light went on, which would be right before the limiter... but I still hit the limiter....

Rockin_Da_Goat
03-27-2007, 03:37 PM
you should be ok if you havnt noticed any problems after. just dont make a habit out of it ;)


oh and get a gmm

PitchBlackGTO
03-27-2007, 03:47 PM
you should be ok if you havnt noticed any problems after. just dont make a habit out of it ;)


oh and get a gmm

+1 (race version)

lcopas
03-27-2007, 03:56 PM
I was testing this OE shift light.... I don't think its my driving skills.... I think this shifter wasn't design well.

Yes - I hit the clutch when the shift light went on, which would be right before the limiter... but I still hit the limiter....

you got your cluster reprogrammed to light the shift light ?...right ?

and YES... the OE shifter is a big POS - changing to a GMM was my first mod -

Dreamcastin
03-27-2007, 04:12 PM
+1 billion on the gmm.

Gilty1
03-27-2007, 04:47 PM
You would know immediatly if you hurt something. If everything sounds ok, count your blessings and :gears:

ROKS ROKET
03-27-2007, 04:57 PM
You would know immediatly if you hurt something. If everything sounds ok, count your blessings and :gears:

I agree, you would have heard some loud knocking/tapping right away. And if you did some big damage your engine would have seized. Most of us M6 drivers have done it at least once, me included.

ROK

Swampgoat
03-27-2007, 05:58 PM
Rock on and don't sweat it if you hear no funny noises. I did it against a Mach one at 140mph one night. Got 4th and 6th messed up coming hard outta 5th at close to redline...
Enjoy your car.

BTW, ya can mis-shift in a GMM too. I like my stock shifter, and can shift like a mofo with it. Doc Gto, another slick shiftin' fool is on the stocker too.
Just depends on what kinda shifter you like. GMM helps, but has its drawbacks too.

ELP_JC
03-27-2007, 06:38 PM
Somebody else posted doing this, and the consensus is if you didn't have the car loaded on the rear, the tires break loose before mechanically overrevving your engine, so you were lucky indeed. And yes, if you damage something, like bending a pushrod or something, it'd be IMMEDIATELY known.

I also downshifted instead of upshifting once while getting to know the car, but nowhere near redline. But yes, it happens to even the best of us. It's just better to know the car well before engaging in that kind of driving. And even then, it's still possible. We have to be fully focused on what we're doing. And if you botched the shift, just let it go since it's much easier to screw up once in N; that's how I did it the first time. Later.
JC

mkturtle
03-27-2007, 06:45 PM
Thanks guys. I'll sleep much better!!!

I think GMM is my next mod. I thought I'd have my shift light activated first, and replace shifter next.... Until then, I'll take it easy, I think.

mmmboulder
03-27-2007, 06:48 PM
I found the best way to speed/power shift from 3rd to 4th is to keep your elbow pointed to the passenger seat. I have a GMM shifter.

Mike

simpleGTO
03-27-2007, 07:05 PM
Been there and done that. OK I think, I went from 2 back to 1 at red line. 3months ago and no problems yet.

Roy V
03-27-2007, 07:15 PM
You're OK dude, if you screwed anything up, you'd know it by now. The advice you've gotten here is excellent.

Now enjoy the car - that's why you bought it !!!!

22fast
03-27-2007, 08:08 PM
I did it against a Mach one at 140mph one night. Got 4th and 6th messed up coming hard outta 5th at close to redline...

BTW, ya can mis-shift in a GMM too. I like my stock shifter, and can shift like a mofo with it. Doc Gto, another slick shiftin' fool is on the stocker too.
Just depends on what kinda shifter you like. GMM helps, but has its drawbacks too.

An LS1 is close to red line at 140 in 5th? I can't believe there is that much difference between the LS1 and LS2. I've had my LS2 to 160 in 5th (bouncing off the speed limiter before I had it reprogrammed) and was barely over 6000 rpm.

Turtle, get the GMM. You will love it. The stock shifter feels like a sponge compared to the crispness of the GMM. Its always easier to miss a downshift, but you will never miss a 2-3 again, period. I have found no drawbacks to the GMM. I have the street version with the stock upper handle.

05gto60
03-27-2007, 08:15 PM
i did a 3-2 shift one time in my old car. i ended up cracking the flywheel. cool thing was i got the dealer to warranty it since they had a problem with the flywheel bolts backing out, so they blamed it on that. i ended up getting a new flexplate, flywheel and throwout bearing for free.

why2kmax
03-27-2007, 08:15 PM
i had to say it!!! otherwise someone else would have beaten me to it!!

i have done the same thing once or twice from 3rd to 2nd instead of 3rd to 4th while street racing. i would also say your fine as long as u got the clutch back in right away.

I did it twice hitting 2nd instead of 4th.
that was about 15000 miles ago.
Motor still quiet and running well.
Rear end still in the car.

I quit buying lottery tickets cuz I used all my luck right there.

GMM going on top of the mixer as soon as it freakin warms up.

TurboDan
03-27-2007, 08:43 PM
I managed to do the same thing even with the GMM. The solution is to "backhand" the shifter when going from 2-3. In other words your thumb point down as you grip the shifter. This will force your hand to push away from your body and you'll always grab the higher gear.

Works great.

KLR GOAT
03-27-2007, 09:16 PM
I accidentally did the 2nd to 1st down shift three days ago...scared the crap out of me. But luckily for me, I have the POS stock rear tires and they gave way and slid...still bounced off the rev limiter though...so far, no problems with the car. I've had the B&M shifter for two years now and this is the first time this ever happened to me, so don't pay too much attention to those people who want to blame your limited experience for the accidental downshift. Keep driving your goat like you stole it!

Swampgoat
03-27-2007, 10:26 PM
An LS1 is close to red line at 140 in 5th? I can't believe there is that much difference between the LS1 and LS2. I've had my LS2 to 160 in 5th (bouncing off the speed limiter before I had it reprogrammed) and was barely over 6000 rpm....

I have 3.91s. Changes everything.
My valvetrain is now built for 7k+ but when this happened I was around 5500 and saw the tach bury at 7 and the rears locked up. Thank God the Kaaz kept me straight!
I managed to do the same thing even with the GMM. The solution is to "backhand" the shifter when going from 2-3. In other words your thumb point down as you grip the shifter. This will force your hand to push away from your body and you'll always grab the higher gear.

Works great.
Bingo!! We have a winner. The flip hand shift is a great way to bias to the upshift.

koman
03-28-2007, 12:34 AM
i think you'll be ok. i hit second at 90 mph looking for fourth. instant tire lock up and horns going off and i realized what happened. my engine has always been "noisy" since day one. it's just gotten progressively so over time. performance is ok.i tried a gmm shifter and it doesn't allow clutchless-shifting like the stock shifter. clutchless shifting allows for faster shift times due to less clutch pedal effort.

TurboDan
03-28-2007, 07:11 AM
i think you'll be ok. i hit second at 90 mph looking for fourth. instant tire lock up and horns going off and i realized what happened. my engine has always been "noisy" since day one. it's just gotten progressively so over time. performance is ok.i tried a gmm shifter and it doesn't allow clutchless-shifting like the stock shifter. clutchless shifting allows for faster shift times due to less clutch pedal effort.

Dude, I feel sorry for your blocker rings! You've got to be PERFECT to clutchless shift without risking damage.

lsx24
03-28-2007, 07:21 AM
You should be fine. If you don't hear any abnormal noises. If you are paranoid you can take your pushrods out to see if you bent one. If you bent a valve, you would know it right away!

CycloneGTO
03-28-2007, 07:57 AM
Several people have mentioned bouncing off of the rev limiter during a mis-shift. Just so you know, the rev limiter only stops you from over-revving the engine via the gas pedal. When you mis-shift down a gear, that is a mechanical overrev, and your wheels can drive the needle WAAAAY past redline if you don't hit the clutch quick. If the rev limiter could stop a mechanical over-rev, then mis-shifts wouldn't be so dangerous.

Roadmaster
03-28-2007, 08:19 AM
Several people have mentioned bouncing off of the rev limiter during a mis-shift. Just so you know, the rev limiter only stops you from over-revving the engine via the gas pedal. When you mis-shift down a gear, that is a mechanical overrev, and your wheels can drive the needle WAAAAY past redline if you don't hit the clutch quick. If the rev limiter could stop a mechanical over-rev, then mis-shifts wouldn't be so dangerous.

These posts are always that way. Its funny.

Electronic rev limiter won't do a damn thing when the driveline is "LOCKED" in gear and the wheels are spinning.


For stock cars, much of the stress is taken up by the clutch --- as this is the one good time to get a slipping clutch!

You can bend pushrods, but honestly that is a saving grace too since the pushrod takes the stress and you don't wack a valve with the piston.

I use to frequent Honda boards, and the missed 4 - 2 downshift is common but far more dangerous. 8k rpm miss to 3rd was zinging some of the 4 cylinders up past 13k rpm and things got nasty very quickly.

JTSnooks
03-28-2007, 08:48 AM
I've done this too, once from 2-1 on a test drive, once from 3-4 in my own car. Didn't hurt the engine any, but I do now have the annoying rear-end whine around 50mph that so many people complain about. Prior to missing the shift I never noticed the noise, so I'm assuming that's what caused it. Gonna have the dealer take a look at a few things and have them at least change the fluid in the diff, if not replace it.