Clutch Disengaging at high RPM?

ragtopz

No power above 4k RPM and bucking does not sound like clutch slip. With clutch slip your car will rev but not accelerate, worse effect in higher gears.

Any misfire or other codes? May be cam/crank position sensors, but codes would help narrow the issue down.

Ben370

No codes. Could it be the flywheel since I didn't change that?

Wilson2608

Is the car still revving and not accelerating or is it just bucking down around 4K?. I thought you said the clutch was slipping

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Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports.

Ben370

revving and not accelerating. but there's a a sudden jolt when it happens. Also now that I installed the new clutch, I think it's sometimes still making contact with the flywheel when the clutch pedal is all way down because it's harder to shift. Could just need some bleeding for that issue though...

rovert

Hi, just noticed you mentioned you fitted the clutch yourself.
No idea of your mechanical skill level so please don't take this as any sort of a dig.
Could you have possibly fitted the clutch disc the wrong way around.
This could possibly explain some of your issues, if it is backwards, the hub of the clutch disc could be riding slightly on the flywheel, which would cause bad engagement & slipping under load.

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08 Skyline 370GT SP Coupe 5AT: Diy TT

Ben370

I put the raised side toward the pressure plate, flat side toward flywheel. Just like the old one was positioned.

B&W_Evader

Couple more ideas for you to consider...
Plugged catalytic converter
Knock sensor getting tripped by some sort of vibration and pulling timing
Someone put a bad tune in her, verify you have a stock tune
Car thinks it's overheating
Maybe someone had the heads off and didn't get all the timing right when putting it back together.
Bad Gas
Water in gas
Plugged fuel filter


Get a cheap OBDII scanner and see what the engine operating parameters are. Not sure if a cheap one can read the knock sensor so maybe someone on here can recommend a good cheap one for you.

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|RIP|6spd-sport|OSG-LSD|XP8|RBF600|Eibach Sways|RE-71R|FI-34Row|Gen3-CAI|Yaw P.S.|

Wilson2608

Imo it has be something wrong with the clutch /flywheel if it's revving and not accelerating. But I could be wrong

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Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports.

Ghostvette

IIRC, all clutches come marked 'this side towards flywheel'. So it might not be an orientation issue. Flywheels can develop hot spots and heat cracks that are visible to the trained observer, but a person new to fixing cars might overlook. That's why everyone recommends changing the flywheel and pilot bearing, along with the clutch, pressure plate and throwout bearing (CSC in this case) when doing a clutch. Also, proper torque and proper torque sequence could be a contributing factor. Did you use a good torque wrench or did you use the 'it's tight enough' mode? I'm not trying to be rude, pressure plate bolts have torque ratings and sequence for a good reason.


While DIY is a great way to learn and save money, IMHO, DIY on a clutch (especially since you said this is your first MT car) was probably not the way to go. It's time to bite the bullet and take it to a shop for professional diagnostics. GL.

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2015 Magma Red 6MT Sport Tech/2012 Fairlady MB 6MT Base (RIP 08032018)https://www.nicoclub.com/FSM/370Z/Coupe/

Ben370

I torqued it right but yeah I'll bring it to a shop.

Edit: I went to a local reputable shop, NM Imports, and they've done 5 370Z clutch jobs in the last 2 weeks. The mechanic was saying my CSC was probably going out before and now I need a rebleed. They normally tell people to come back after driving a bit to bleed it again. So I'll have them rebleed it since I used a power bleeder last time anyway...

Ben370

Update: Turned out to be the flywheel as suspected. Thanks for the help!
Here's the old one. I replaced it with the Z1 midweight flywheel.