braveheart3158

My friend has a 2015 C7 Manual with 10k miles. He is not good with the computer so I said i would reach out to the forum to see if anyone could help.

1-Started engine with clutch engaged and in neutral. . Shiftier would not shift out of neutral into any gear.
2- Engine off...shifter would shift out of neutral into any gear
3- Started engine in 1st gear, clutch and brake engaged and parking brake on. When the engine turned over the car lurched forward slightly as if the clutch was not engaged. Now the it shifts thru all gears with engine running.

Any one know what this may have been? He is hoping it was temporary but would like to find out what it might have been.

He is not 100% sure but a short shifter may have been installed by a previous owner. He has never had a C7 before.

thanks in advance

thrilled

Maybe the computer has something to do with it.Take the cable off the battery for 15 minutes then hook it back up and try again.If that don’t work then it would be time to see the dealership.

braveheart3158

Thanks for the idea. If it happens again I will suggest he do that for sure. I will also suggest he bring it to the dealer sometime this week to check it out. For his sake i hope its under Warranty.

He also said it is difficult getting it into reverse. I guess the dealer can look at that to.

CourtneyJudd

same identical thing happened to me... i bought a 2014 Z51 M7 about a year ago and didn't like the stock shifter.... replaced it with a MGW and loved it... worked great... a month ago got in it and cranked it up and would not go in any gear.... turned it off and it would go in all gears.... cranked it back up and same thing. finally started it up in gear.... made a small lurch and all back to normal. It has never happened again.... no clue what or why this happened but maybe something to do with the skip 1 to 4 th lock out.... maybe someone has the answer! Courtney Judd

BrunoTheMellow

That's odd. Almost like the clutch wasn't pulling out. Like mechanically bound. And the lurch unbound it.

CourtneyJudd

Don't think the clutch had anything to do with it. With the engine off you could shift into any gear.... clutch or not.... more like the 1st gear to 4th gear cut out at low rpm was preventing any shifting but then again what do i know according to my wife! CJ

FYREANT

Dont think it has anything to do with 1-4 lockout. If it did, you’d be able to get it into at least 4th gear. Bruno is prolly right. Likely has to do with clutch disengagement sticking or maybe the throw out bearing getting stuck somehow..

Bill Dearborn

Clutch pedal in is clutch disengaged, clutch pedal out is clutch engaged. The OP's friends problem sounds more like an issue where the clutch is sticking and not completely disengaging similar to what you might get before the clutch pedal sticks to the floor. My C6Z would start doing that while on track. After a few laps the clutch pedal wouldn't disengage the clutch until further down in its travel and the point where it disengaged would drop lower and lower until the pedal stuck on the floor. After it stuck in the down position I could use the toe of my shoe to pull it back up. It would work fine for a while and then the disengagement point would drop lower and lower again. GM sent all owners a letter stating they would warranty the clutch master cylinder for 10 years after the car's in service date and would replace the master cylinder if the clutch stuck to the floor during that period. Once the replacement master was installed the clutch problem disappeared.

Bill

rrsperry

Here's my WAG, (wild *** guess), IF the car hasn't started and been run, (winter storage), the clutch disc is/was, rusted/stuck to the flywheel. It could have been very humid when stored.

Try to start the car in gear with the clutch pedal down, (disengaged), and his foot HARD on the brake pedal. That will free the disc.

If that doesn't work, you have an issue with the clutch hydraulics.

RyanC7

I would do the ranger method and flush the fluid. That stuff gets nasty quick.

braveheart3158

Turns out he was not pressing the brake what trying to release the parking brake!!! Lol

JHEBERT

braveheart3158

I posted above that the parking break was not disengaging because he had not stepped on the brake pedal to release the parking Brake. Always seems to be the most obvious lol

Submerge

Internets_Ninja

This is a mechanical issue with the clutch itself and not some electrical issue. The fact that the car lurched forward in 1st gear with the clutch pedal depressed means the clutch was contacting the flywheel, a tell tale sign you clutch is having mechanical problems. Could be the Master/Slave that is not creating the necessary pressure to lift the clutch off the flywheel face or something in the pressure plate itself.

Also, note, the reason you can shift all gears when the engine is off is because the input shaft is not spinning inside the transmission. You don't even need to press the clutch in to shift into any gears for a trans/clutch that is operating properly. So this part is irrelevant to your issues.

Submerge

Ghostnotes

I have to manually disengage mine no matter what.

Internets_Ninja

I have to release mine always. If I don't the car won't move.

Same for me. I have a 2015 so maybe its related to year? Seems rather unsafe that the brake would auto release in the manor described above.

FYREANT

braveheart3158

The issue was that he was not stepping on brake pedal to release the parking brake. Thanks.