Can anyone give me the symptoms of a mechanical over rev. I down shifted 3 gears and hit the rev limiter. it bounced off it a couple of times and then i quickly engaged the clutch. So can you guys tell me what to look for (sounds, loss of power?). I am so worried. I almost cried afterwards Please HELP ME!!!!


Over Rev

 

With over rev, you can have valve float, a valve may slghtly touch a piston and go out of spec or even worse, get bent. In extreme cases you can even have a damaged piston and scratched cylinder walls If a valve comes in contact with the piston hard enough... In mild cases you will need to do a valve adjustment to restore them back to spec after the shock.

Symptoms:
-Serious damage: it would be apparent right away. YOU WILL KNOW.
-Mild damage: your engine should tick fairly loudly if a valve is bent.
-Very slight damage: If there is a very slight tick, then you probably need a valve adjustment.
-It can also happen that NOTHING happened, maybe it wasn't very high up in the RPMs, maybe you clutched out quickly enough...

If your car is still not making any unusual noises, consider yourself lucky.

If I said anything wrong, please correct me as I am not a mechanic.

 

Look for sixteen small dents in your hood, accompanied by a moderate to loud clattering!

 

Sev,


yeah my engine is ticking I guess the good news is that it isnt ticking loudly. I will set an apointment with my dealer. THANKS SO MUCH!

Bobby

 

Great info Sev...thanks.

 

Always remember there is no Rev Limiter when accidently down shifting. It is the momentum of the engine taking it past 9k RPM not the mechanics of the engine.. so fuel cut out could not help.

 

Great info Sev, thanks!

Also, maybe a bit obvious, but proper shifting technique will also assist in preventing accidental misshifts that could cause a very serious case of bent valves.

see here:

http://www.turnfast.com/tech_driving/drivi..._shifting.lasso

 

Interesting shifting article- but I'm not sure I believe it. The objective is to move the lever to the next position. Whether you grip it, cup your hand, flick your wrist, or even if you have no wrist because you have a hook in its place should make no difference. The objective remains the same- move to the appropriate gear.

Watching rally drivers on ESPN, I recall them grabbing the shifter with their hand/fingers with no specific technique or regularity except that they let go of the shifter immediately.

I do see the wisdom in not yanking it hard or forcing it though. But whether you use your wrist, arm, hand or other appendage shouldn't matter unless you are doing it solely to prevent yourself from yanking/forcing the shifter.

What I think is much more important is your clutching technique. I think mine is lousy and I've never found a good article that can put into words the correct feel of gas/clutch.

-B

 

Rally cars have sequential transmission, they only go up and down for upshifts and downshifts. Those drivers have little to worry about in terms of misshifting. I think british touring cars and champ cars also have sequential transmission as well, just a couple more examples.

I personally think that if you cup the knob instead of gripping, you lessen the chance of shifting into the wrong gear, at least with me and my Voodoo knob. If you grip it and you're taking a slight turn at high speed, you may pull it a certain direction instead of straight down the gate.

BTW, what's your clutching technique?

 

i cup it from 1-2 and 3-4 .. and push it from 2-3 and 4-5..