996 engine overspeed

[wbkjr]

I was in reverse, backing out of a parking space in my '99 996 C4. A jerk came flying by, forcing me to jamb on the brake and disengage the clutch. But my foot (size 12) also caught the gas pedal and I heard the engine scream. I was looking backward so I had no indication of the max rpm. I was stopped in a few feet but noticed the engine had stopped. It restarted, and seems to run ok, but I was wondering if there was something like an overlimit switch that shut down the engine at a certain RPM? If there is, does anyone know the RPMs at which it kills the engine? I am wondering why the engine would stop otherwise. It was not the case of releasing the clutch. Thanks for any information.

[txhokie4life]

I was in reverse, backing out of a parking space in my '99 996 C4. A jerk came flying by, forcing me to jamb on the brake and disengage the clutch. But my foot (size 12) also caught the gas pedal and I heard the engine scream. I was looking backward so I had no indication of the max rpm. I was stopped in a few feet but noticed the engine had stopped. It restarted, and seems to run ok, but I was wondering if there was something like an overlimit switch that shut down the engine at a certain RPM? If there is, does anyone know the RPMs at which it kills the engine? I am wondering why the engine would stop otherwise. It was not the case of releasing the clutch. Thanks for any information.

There is a rev limiter.

Not sure why your engine stopped.

The only way I know to over rev the engine is via downshifting and causing the wheels to back rev the engine (like engine braking)

and with the lower gear ratio, it cause the engine to over rev. I could be wrong though.

You could check with a Duramatic to see if the engine indicated over ranging.

More than likely nothing really happened,

Mike

[Loren]

I was in reverse, backing out of a parking space in my '99 996 C4. A jerk came flying by, forcing me to jamb on the brake and disengage the clutch. But my foot (size 12) also caught the gas pedal and I heard the engine scream. I was looking backward so I had no indication of the max rpm. I was stopped in a few feet but noticed the engine had stopped. It restarted, and seems to run ok, but I was wondering if there was something like an overlimit switch that shut down the engine at a certain RPM? If there is, does anyone know the RPMs at which it kills the engine? I am wondering why the engine would stop otherwise. It was not the case of releasing the clutch. Thanks for any information.

:welcome:

Nothing to worry about.

As long as it was caused by stepping on the gas the rev limiter will protect the engine.

It is when you make a bad downshift (i.e. 4th to 2nd) that can force over revs that the rev limiter can not protect against and could cause engine damage. Likewise with a spin - always put the clutch in first thing in any spin.

[judgejon]

I just read this short interesting thread of messages.

Thank you, search engine.

I hit the over rev limit today.  

Going through some twisters in 2nd gear.  Engine seemed to cough and sputter.  I looked down and I was pushing past 7k.

over revs.

Slowed some, no reoccurrence.  engine seemed strong.

I also noted this in a recent thread about some added aftermarket dash lights.  Over rev indicators likely.  At least one of them.