Low mileage and bad clutch?
 

Hi guys. I am in for a car with very low mileage - 17.000 miles ('08, VQ35HR). The issue is that clutch bites extremely high, basicly when you let the pedal go. The clutch is not slipping, I haven't noticed it. If the clutch is gone obviously it had a hard life. Was it either driven in the city a lot or it was beat as hell. Would hard starts relate to this symptoms? Or the problem could lie elsewhere?
My worry is that even DMF can be bad. I am in the process of buying this car and I am looking at a hefty bill.

EDIT: Darn it. This should be moved to 350Z arena :/ sorry

If the clutch pickup point has changed then you need to bleed the system, if it's just high then you can get your head under the dash and adjust it at the pedal.

It's more than just high, it's allll the way up. Basicly the last 1/2 inch when you release the pedal.

Has it always been there? Like I said, you can very easily adjust the pickup point at the pedal. I'm not sure what the pedal / master / slave ratios are, but the the difference between a brand new and worn out clutch is a few mm, so you probably wouldn't notice it in the pedal.

to me the nissan always had a high release, i wouldnt adjust it via the rod to much, you could lead to not fully engaging or something

if you dont like the engagement point, get the rjm pedal

I am looking to buy this car and I don't really know how the clutch was till now. The seller said yes, the clutch should probably be replaced - he's not even sure about it. Be aware that the car is stock, owned by the 1st owner, older gentleman who indeed have a lead foot. And we're talking about 17.000 miles the car has. That's basicly new car/clutch.
I know the clutch can be tricky on these cars. I searched through this forum and some others, also googled but couldn't find anything on this matter. If it's only bleeding that should be performed than it's good. If this is a destroyed clutch which consequently damaged the DMF too I cannot know. But I would be in for a fat bill.
Does riding the clutch and clutch dumping manifest as the same symptom of worn clutch?

My mistake, didn't read your first post carefully enough and didn't realize this wasn't your car. Like Trav said the release on these cars has always been pretty high, and 17k is really low for the clutch to be worn out. Easiest way to tell if the clutch is slipping is to get up to freeway speeds, put it in 6th gear, then press the gas as if to pass while watching the tach (don't floor it as that will lug the engine). If the clutch is worn, the revs will jump up without a major change in speed, then they will come back down as you begin to accelerate.

Once you get the car, I wouldn't be too concerned with over-adjusting the pedal - if you adjust it too far it'll be pretty obvious (it would be tough to get in to gear with the engine running), and you'd just need to back your adjustment off a bit.

just note.... plan on dropping the trans to replace the csc eventually. mine first went out at 36k miles, and then again at just shy of 50k (replaced with oem). spend the money and do the zspeed setup

I would be concerned if a clutch was bad at 17,000 miles - someone didn't know how to drive a MT! Believe it or not, my 03 has 163,000 miles on it and still on the original clutch, and I used to track it and drive it pretty hard at other times, including many trips to ZDayZ, before getting my 90 TT 5 years ago, when it became just a daily commuter car. But, not sure yours is bad anyway, do that 6th speed test and see if its slipping - you can do that on a hill too and maybe not even 6th gear - just low RPMS and see if it accelerates.

Thanks for input. I am aware of all the things mentioned here. As said before I went through this forum and others.
The thing that bothers me is not knowing why this would happen. I am quite solid on destroyed clutch. And I cannot imagine what was happening with the car since it looks really nice. Never resprayed. And I don't get any answers from the seller. He's saying because these are sports cars (bull sh!t), that this happens because someone is riding the clutch, but he's not giving any explanation why this happened on his car. He simply "doesn't know". Would this relate to heavy clutch abuse?

It's a used car.....its not going to be perfect, use the clutch as a bargaining tool to get price down

Well I bought the car. Seems like car had a bad CSC way back when it was new. It was replaced under waranty but they haven't replaced the clutch disc and since the fluid obviously leaked over the clutch which caused it to slip eventually killing it. I am considering a full aftermarket kit from Xtreme. I think they call it Stage1 with their own CSC and lines. The only mistery that remains is the DMF. If it's still good or burned. If I have to replace it I need to decide going with OEM DMF or most quiet aftermarket SMF - supposedly from Xtreme.

I know very little about the Xtreme clutch (I presume it's the ACT Xtreme which has a decent rep) but I can tell you that the go-to clutch set up on the HR is either of the JWT (Jim Wolf Technology) HD units. I say "either" because there are two versions (maybe more), one with a lightened flywheel (~14lbs) and the one I've used on an '07 GT trim car, same clutch but with 26lb iron SMF. Along with the Z Speed HD CSC, this combination has been quiet (still a bit of gear noise but hard to eliminate that on HR equipped with the JK-series trans - update to CD009).

My opinion, well, I don't like lightened flywheels, BTDT, ehhhhhh. So, I like the combo mentioned above and you might consider going with the ZSP CMAK (clutch movement alteration kit - essentially converting/backdating the internal slave to external operation.) No personal experience with it but gets amazing reviews from other Z owners, especially the Z34 VHR crowd. Check the condition of the DMF though, if no burn/scoring on it, you can save $$ by re-using it and just R&R the clutch assy. With so little miles, can't imagine it to be that much toast unless the P.O. really rode or dumped the clutch a lot.

EDIT: just noticed you mentioned "quietest"... trust me, you'll want to either retain the DMF (if possible) or go with the higher weight FW mentioned. Just one of the things I hate about lightened flywheels. Only place I'd want a lighter unit is on a track car where gear noise is a secondary concern.

Xtreme is an independant company from down under - Australia. The reason I am looking at them is I was told their SMF makes the least noise from the drivetrain. I was actually decided on JWT but supposedly it is loud. I have no experience with SMF. Going heavy with SMF should reduce noise, right? There's no 350Z HR knock off's so it's the OEM DMF, costing around 1.500 USD over here.
Being stock car and I don't plan on racing the car on track I would like to have very street driveable car. I did consider Z Speed but they don't have a "store" here in Europe. Shipping it over and adding all the costs, taxes and import fees just doesn't add up to common sense.
I will consider advice on keeping/replacing the DMF. But going with aftermarket clutch and especially HD CSC.

Ahh, OK, got it. Didn't see that you're in Europe (or didn't make out "SI" as being on the Continent. :icon17:)

FWIW, the primary reason we chose the iron flywheel for my kid's GT was exactly that, noise abatement. (Along with the other characteristics akin to stock....no freeway lugging, good shift smoothness, etc.) Both of my Nismos were horribly noisy, even stock. Wasn't going to go with something that goes against the physics and makes it even worse. When you're done, please report back on the outcome, I'm sure many would be interested in hearing how it all works out.

Making an update on the matter.
Well, I've made like 1.000 miles and clutch disc broke itself in, so it's not slipping anymore. Solid as a rock. Heavy judder and shaking when taking off still remains though. You have to let the clutch go quite quickly and do it around 2.000-2.500 RPM and it's better.
To solve this issue I've bought HD CSC (Z1 Motorsport) and new DMF and clutch from Nissan (got a good discount but still very pricey). You probably already know this info but to reconfirm it - OEM Pressure plate is made by Luk, metal clutch disc also Luk but organic material from Valeo. You cannot get these parts as rebranded OEM for HR engine.
Still don't know if DMF is actually bad? Could be only the clutch disc. Why I went with OEM DMF? Two reasons: I want to keep the car stock in case I try to sell it. People over here don't like modified cars; I mean they do but they are PITA to sell. And the second - I would like to have clutch and transmission quiet. Although neutral rollover is loud on this transmission (CD5 #1). I guess that's normal?

Today’s update. Clutch is getting better and better. Juddering and shaking when taking off is almost gone. Bitting point on the clutch comes sooner and pedal feel is also improved.
I am starting to think thatthis clutch issue is from car not being driven enought. Car did basicly 2.000 miles per year. Could that be possible?