LS1 Based Engine Tech LS1 / LS6 / LS2 / LS3 / LS7 Engine Tech

Car missed a shift and over-revved....what should I check for posible damage?

Thread Tools
 
Search this Thread
 
Old Jan 30, 2004 | 11:04 PM
  #1  
Schantin's Avatar
Thread Starter
Registered User
 
Joined: Oct 2001
Posts: 204
From: Hawaii
Unhappy Car missed a shift and over-revved....what should I check for posible damage?

The title says it all. The f#$%^'n Hurst shifter sure felt like it was in third gear....actually turned out to be first It really pissed me off because I'm usually very careful in my gear selections!

Anyhow, the car revved instantly to about 6500RPM. I was off the gas within a second and the rev limiter kept it bouncing between 5900 and 6200 for about 4 seconds. This happened about 30 miles from home entering the interstate.

The car ran fine the whole way home. I popped the hood with the engine running. Valvetrain noise is the same as usual and no SES lights illumnated.

So..... what can I check to ensure I didn't totally F-up my engine? If I bent a pushrod (or more), would it increase valvetrain noise, cause stumbling problems or worse? Can I verify the condition of things w/out pulling off both valve covers and visually inspecting the pushrods, springs, etc?

if not, what should I be lookng for? (Aside from an obviously broken or severly mangled part ) Do I need to use an indicator or smiliar tool to ensure the pushrods remain straight...the lifters are not collapsed, etc.

Like I said before, after 30 miles of driving the car seems to run fine with no unusual power loss, noise, etc. I'd like to verify that things really are fine though.

I appreciate any help that can be provided. Thanks in advance.

Schantin
2002 Camaro Z2 M6
Old Jan 31, 2004 | 12:09 AM
  #2  
AL SS590 M6's Avatar
Moderator
 
Joined: Jul 1998
Posts: 6,247
From: Charlotte,MI USA
If it is still running fine and has no extra ticks in the valve train then you probably didn't hurt anything.
Lucky you.
Old Jan 31, 2004 | 08:50 AM
  #3  
NoSlowCamaro's Avatar
Registered User
 
Joined: Oct 2003
Posts: 158
well i know one thing...you definately without a doubt severely over revved it, depending on your speed...how fast were you goin when you accidentally hit 1st?? And also..that wasnt the rev limiter...the rev limiter cannot prevent mechanical over-rev..so..if you miss a gear, dont count on the rev limiter to save ya.

Last edited by NoSlowCamaro; Jan 31, 2004 at 08:53 AM.
Old Jan 31, 2004 | 09:36 AM
  #4  
steve-d's Avatar
Registered User
 
Joined: Nov 2002
Posts: 122
Re: Car missed a shift and over-revved....what should I check for posible damage?

Originally posted by Schantin
Anyhow, the car revved instantly to about 6500RPM. I was off the gas within a second and the rev limiter kept it bouncing between 5900 and 6200 for about 4 seconds.
Actually, chances are you went much higher. The tach isn't capable of instantly reacting to a mechanical over-rev. If you were near the 4,500 mark in second and banged first, look for 7k+. In this cold weather, I'm surprised you didn't just lock up the rear and skid.

Steve

Last edited by steve-d; Jan 31, 2004 at 09:43 AM.
Old Jan 31, 2004 | 09:41 AM
  #5  
BlackTA02's Avatar
Registered User
 
Joined: Feb 2002
Posts: 43
From: Plano, TX USA
"... car missed shift ..."

PLEASE !

Sounds like operator error to me. Don't beat yourself up over it, though. I've done the same thing (once) and no damage resulted (thankfully). It happens.
Old Jan 31, 2004 | 02:56 PM
  #6  
AJ1978TA's Avatar
Registered User
 
Joined: Sep 2001
Posts: 113
From: CT
You should've put your foot into the clutch ASAP, never mind let off the gas. I shifted from 3rd to 2nd instead of 4th once but I put the clutch in quick when I felt that it dropped a gear. You can bend pushrods easily when you over rev. If you hear a loud ticking/knocking kind of noise, it might be a pushrod. If everything sounds OK, you might have gotten off easy, but don't do it again for sure.
Old Jan 31, 2004 | 04:44 PM
  #7  
locosteelersfan's Avatar
Registered User
 
Joined: Aug 2003
Posts: 192
I second that. I assume you didn't use your
clutch but still why'd you leave it in gear for
as you say 4 secs of rev limiter. Hurst or no Hurst
that's on you.

Good news is if something broke you'd know it.
Old Jan 31, 2004 | 04:45 PM
  #8  
kinyu's Avatar
Registered User
 
Joined: Mar 2003
Posts: 190
From: Phoenix, AZ
I did on the track doing about 80 ... the rear end locked and I jammed in the clutch. Didnt do any damage though (that I know of)
Old Jan 31, 2004 | 06:46 PM
  #9  
Schantin's Avatar
Thread Starter
Registered User
 
Joined: Oct 2001
Posts: 204
From: Hawaii
Thanks for the info (and encouragement.) For those that asked...I didn't disengage the clutch because in gear the engine RPM limiter will pull the RPM's down to acceptable limits faster. I'm sure someone will debate this with me..... but I'm not going to over-rev the car again to test other methods. (My method brought the RPM under 6300 in less than 2 seconds counting reaction time to the mistake )

After driving the car another 30 miles today I don't hear anything "weird". The valvetrain has always been noisier than my old LT1, but I don't hear any unusual ticks or knocks. The car will still pull hard through 5,000RPM s well. Guess I was lucky!

Finally....of course I'm the one that selected the wrong gear...it is a manual. It certainly felt like it slid into third though. (Damn Hurst shifter !

Schantin
2002 Camaro Z28 M6
Old Jan 31, 2004 | 07:43 PM
  #10  
locosteelersfan's Avatar
Registered User
 
Joined: Aug 2003
Posts: 192
Well I'll be the one to discuss it with you, for
the sake your engine should your "Hurst" screw up
again. Think of it this way, run your car to 5000RPM
in 1st gear and let off the gas, then repeat but this
time shift it into neutral. I guarentee you it will come
down faster plus your taking the gear factor out of
it.

You overreving the car wasn't caused by the engine
but the transmission so engaging the clutch removes
the cause of the effect, there is no arguing that.

Your rev limiter only cuts off the fuel, like ASR.
Old Jan 31, 2004 | 09:38 PM
  #11  
robb4964's Avatar
Registered User
 
Joined: Oct 2002
Posts: 1,130
From: Kentucky
Hey man , I wouldnt sweat it , when I first got my LT1 6 speed , I was out running the hell out of it , and I went into first on accident , from third , hauking *** , It hit the rev limiter and OMG its sounded awful ....I was sure I ruined something ... 50k later , she is running like a champ
Old Jan 31, 2004 | 11:02 PM
  #12  
JaysGone's Avatar
Registered User
 
Joined: Aug 2003
Posts: 302
From: Boca Raton Florida
Shhhhhhh dont tell anyone but 6500 isnt over reving the engine. That red line is there to trick you into going slower. Thats way past peak tourqe and horsepower. 4 seconds is no big deal. But you are lucky that the rear end didnt lock up. Spend some $$ on a decient shifter a plain metal bar is better then a Hurst
Old Feb 1, 2004 | 04:43 PM
  #13  
NoSlowCamaro's Avatar
Registered User
 
Joined: Oct 2003
Posts: 158
yea but once again. The rev-limiter will NOT prevent the motor from over revving, if you downshift at the wrong speed/RPM...it can only prevent the motor from over revving if your on the gas..accelerating..not from physically over revving the motor.
Old Feb 1, 2004 | 05:36 PM
  #14  
Inharmonic's Avatar
Registered User
 
Joined: Apr 2001
Posts: 2
From: Franklin, TN, USA
I had a friend with a '96 Z28 that went from third at redline to second instead of fourth by accident. Scared the crap out of him, but the car was fine. Kinda like Russian Roulette, though.
Old Feb 1, 2004 | 05:52 PM
  #15  
EastLa's Avatar
Registered User
 
Joined: May 1999
Posts: 109
From: Leeds, AL
A buddy of mine was on the Road Course and did the 3rd-2nd accidentally. He said that he got out of it and shifted to neutral. After that he said he hadn't lost any power, nor was there any more valvetrain noise. After the session, he pulled into the pits and pulled the valve covers. 7 of the 8 pushrods on the driverside were bent. He was shocked, saying, "it never lost power."

Don't want to dampen your spirits, but those pushrods suck. I wouldn't doubt if mine are bent, and I've never over reved mine.



All times are GMT -5. The time now is 12:08 AM.