New to this forum so please bare with me. H/C/I 2002 Z06. This all started after i did a pull on the way home on the highway. As soon as i clicked 4th, there was a horrible grinding sound coming from the drivetrain. I limped to an open area off the highway and thats when it started. The car would start but the engine begins to stall around the engagement point of the clutch pedal and if i let it all the way out, the engine dies. The engine will idle all day on its own as long as the clutch is pushed in, only when i release it is when it dies. Put the car in 1st gear and let the clutch slowly out, it got all the way out for a few seconds and then the entire drivetrain jolted forward and i moved for about 20-30 feet when it felt like the entire rear end locked up and the tires skidded for a few meters. That's when i got it towed to work (im a mechanic). I first replaced the throwout bearing/slave, put it all back together and it had the same issue. (Did an OEM throwout bearing/slave and had one installed before i replaced it. Also i have a Monster LT1-S twin disc), I figured the clutch was binding because the torque tube spun fine when i had it out of the car to do the throwout bearing/slave. Took everything apart again and replaced the flywheel, clutch (did another Monster twin disc), and pressure plate. Double checked the torque tube wasnt binding and verified its ok. Measured the pressure plate to slave cylinder and verified ok as per Monster specs. Start it all up and still have the same issue. Wheels spin fine in neutral with engine off and also spin fine in any gear. Now im at a loss. Tried my spare key, didnt work.

Worth noting, hours prior to all this happening, i lost my A/C control panel and read somewhere that it was the contacts on the back of the ignition switch. Wondering if somehow thats also causing this issue? But then that doesnt explain the horrible grinding i heard getting off the highway. Maybe the trans is partially stuck in gear but then wouldn't there be grinding when i start it? Any help is appreciated, thank you in advance.

 

If the car just stalls when letting out the clutch (with no grinding sounds or wheel lockup) it may be a column lock issue with “2 MPH fuel cutoff” in which a work around called the LMC5 wired into the BCM will fix this or you can remove the column lock relay if installed which is above the BCM and check for damaged or corroded connections…seeing any DIC messages like “pull key wait 10 seconds” ??…so are you losing power to the HVAC module ??…can you communicate with it with a scan tool ??…I’m right across the river so if you need help let me know…doubtful the ignition switch will cause this…you will have other circuits that would also be affected…if you want you can PM me your number.

 

Sounds like there is something going on with the transmission or differential, and you will not hear any grinding when starting because you have the clutch depressed which is disengaging everything beyond the clutch.

 

Even with the car in gear, on the ground or in the air on a lift, with the engine off, it moves with no weird noises in all gears. The drivetrain spun fine while it was out of the car, i only heard that grinding sound on decel the first time all this started happening

 

Don't know what to say other then it you might have to disassemble the drive train and inspect the torque tube internals, it has to been something downstream of the clutch since there is no problem with the clutch depressed which of course means that no rotational power is being delivered past it.