I have a problem with my drivetrain that I cannot figure out. I have/had a few ideas as to how to fix it, but now I think the problem lies deeper.

I have a bad bounce that happens at around 2,000 rpm. It feels like my clutch is grabbing then releasing over and over, sending shockwaves through the line. This happens when it is cold, but also happens sometimes during low-load driving. Above 2,000 rpm there is no problem. If I coast to a stop sign in 2nd gear I feel a hiccup and the revs drop right around 2,000 rpm. Almost as if there is so little load it is causing slack and movement in the system.

I at first thought it was the "diving board" effect caused by a bad rear diff. bushing. I had that replaced, as well as the front bushes with SPL. I also had whiteline poly sub-frame bushings installed. This made the problem slightly better, but it still bounces.

My clutch has also been getting stuck halfway off the floor and I have to pull it with my foot. This has happened a few times in traffic during high heat days. I checked the clutch fluid and it had dropped. I refilled the fluid, then got underneath my car to check the line.

The hard line that connects to the slave cylinder was leaking, so I tightened as tight as I could without stripping the fitting. The fluid level has not dropped since (1 week). The clutch has not gotten stuck, but it continues to bounce and feel loose under low load.

The clutch does not slip under high load. It operates completely fine, except for these issues. I can drive around the problem or try to ignore it, but I am afraid it is a mechanical problem.

What are yall's ideas? Do you think this is a drivetrain or suspension issue? Has anyone felt this sensation before? If so, what did you do to remedy it?

 

Out of 67 looks nobody can help me. Anybody???

 

have you tooken your car in for service for the 07 recalls...

search...it's somewhere around here...

if not take it to the nearest stealership

 

Could you make a video (with sound included)? Maybe have a passenger film with the tach and road ahead in frame when the problem happens?

Does it have any problems in neutral/when the clutch pedal is pushed? Or is this only a problem at a specific rpm under load?

Does it do it during both acceleration and deceleration or just under deceleration?

Does it happen in every gear at the same RPM or just first gear?

 

Maybe have a passenger film with the tach and road ahead in frame when the problem happens?

I'll see what I can do this weekend. I work at Texas Motor Speedway and we have Dirt Track Nationals this weekend.

Does it have any problems in neutral/when the clutch pedal is pushed? Or is this only a problem at a specific rpm under load?

The only problem in neutral is an increasingly loud chatter. I can also feel the chatter through the pedal. Mostly the bounce is around 2k rpm.

Does it do it during both acceleration and deceleration or just under deceleration?

It mostly does it during acceleration, but under deceleration the revs just seem to drop at 2k rpm with clutch out. If I let off in traffic at around 2k rpm it will bounce, but not as bad as under acceleration.

Does it happen in every gear at the same RPM or just first gear?

Almost every gear. It is typically only in the morning when the engine is cold.

 

Welcome to the HR world.

 

I bought the car used, and the stealership that pre-sale inspected it told me that it had been serviced for the recall and the CSC had been replaced. I have some paperwork that shows the exact mileage and date, but not in front of me.

This could be the issue, but I'm not sure.

 

From the description, I get a mental image of a jacked up clutch plate but, I can't figure why it would be so well centered around 2k.

The focus at a specific RPM makes me suspect the motor, but I would also expect a fault light. (plugs, vacuum hose, etc.)

I can't think of anything that explains all the symptoms at the moment.

Maybe someone with more mechanical expertise will chime in.

 

I would lean more towards the clutch plate. The engine runs strong with no misses or bobbles all the way to redline. As long as I put the engine and drivetrain under load I get no bouncing.

 

Read here:

https://my350z.com/forum/vq35hr/3078...g-warm-up.html

 

Is it a thump thump thump, like you're bouncing off the line at launch, or is it slowly letting off the clutch and the back end jumps 1,2,3, out of first and you can remedy it by re-clutching and relaunching with a slower clutch release?

 

So I read the 400+ post that was linked below, and I'm pretty sure my problem is the same as a lot of other people. Sadly nobody knows exactly what causes it, but I'm leaning towards a warped clutch/flywheel.

The car has over 60K and with the HR's history of clutch and CSC issues the clutch is the most logical place to look.