Micah

Maybe I missed this - when you said lack-of-diligence, did you mean that something specific happened before you noticed the vibration - a hard launch, etc?

Is that a 350Z I spy in your garage? Very, very pretty S, BTW.

Micah

jonnybgood

I agree with the consensus here about the balance shafts. Clarks Garage and Arnworx talk about this at length.

Your car is really nice. Keep that paint in good condition. I now know what my car would look like with a good paint job.

Hope to see you on one of our get togethers.

pointfivezero

Micah - my lack of diligence was failing to have the car inspected before purchasing it. I was pretty much seduced by the looks and salespersonship of the original owner.

Jonnybgood - thanks for the compliment and sharp eyes. My daily driver is a 2003 350Z Touring model I preordered in November 2002. I'm attaching a couple of photos for your viewing enjoyment.

Thanks,

Tim

BeerBurner

Nice Z! And you're a member already?

There isn't much I can add about the balance shaft, except to say that mine is out of alignment as well. Although in my case, it was accomplished via a missed shift... <grumbles>

BB.

Micah

Tim,

Nice Z. So, it has always had this vibration? If so, what did the PO say it was due to? How long ago did you purchase the car? When you stated the clutch had been replaced, do you have the records for it from the PO? Did your current wrench do this clutch install as well?

Also, do you have any records showing work done to the camshaft chain pad and/or tensioner?

Micah

pointfivezero

Hi Micah - I bought the S only a few weeks ago. Had been looking for a replacement for my 87 951 I sold before moving to California in 1999, a decision I always regretted.

I have all the receipts from the original owner. (I'll try and attach a spreadsheet). He lived less than 20 miles from me. The clutch, water pump, belts and tune up were done by a different mechanic than I am currently using. Since he advertised the car as "mechanically perfect", he didn't mention the vibration and I failed to notice it during our brief test drive.

We are going to focus all our efforts on the balance shafts for now. I'll follow up with another post when I have some additional information.

Thanks,

Tim

Micah

Tim,

Lots of nice records there. What I'm concerned about is this: The PO knew about the vibration. He had owned the car since day one, already been through a pair (at least) of belt changes, and probably understood ever creak, rattle and moan the car made. He puts a new clutch on, and for some reason sells it less than 500 miles later?

I think that the original rubber-center unit in the car was replaced with a later spring centered one, and you are getting some severe drive-train backlash a la:

https://rennlist.com/forums/showthre...utch+vibration

Likewise, I didn't see anything regarding the tensioner pad(s) top and bottom being replaced. Do this asap. People's opinions vary about doing both pads, but it is cheap insurance. Your S (all the 16 valvers for that matter) has an additional weak-point not shared by your previous 951 or any of the 8vs. I don't own an S, but I've seen first-hand (twice) what happens with chain/tensioner failures. Many on this board have as well. Thousands of dollars in repairs.

GL - your wrench sounds like he knows what he is doing IMO. You could also call those mechanics used previously and see if they remembered specifics about the jobs done to the car - I.E. the PO complaining about excessive vibration, etc. The root of this problem lies with finding out what was up before you bought the car.

Micah

pointfivezero

Thanks for digging up that post. The mechanic speculated on both the torque tube and the possibility that they may have used the sport disc. The more I learn, the more I respect my mechanic's knowledge and diagnosis. Obviously, I'm not real happy about the potential cost of the non-balance shaft solutions.

BTW, the original owner's reason for selling (at least, what he told me) was that he purchased an old 911T (I think) he was going to restore to an RS.

Thanks again!

Dmitry S.

It's not the torque tube, with the clutch in, the torque tube will no spin, and thus not cause a vibration at a certain RPM.

Just realized the clutch wouldn't spin either if you push in the petal. If the vibration is still present with the clutch pedal depressed, you can eliminate the clutch (at least the friction disk) and torque tube.

pointfivezero

Thanks Dmitry! I will check the vibration with the clutch engaged tomorrow and let you know. My guess is the vibration will be present, regardless of clutch engagement.

jonnybgood

Tim, Take a good look at the pictures in this link. This is what Micah is talking about.

Tensioner Failure

pointfivezero

Wow...that was tough to look at, even on an empty stomach. I will review the receipts (I left them with the mechanic) and make sure the tensioner pads were replaced. Do you happen to know the part number I should be looking for?

Thanks!

Tim

Peckster

Han ha, Porsche only sells the complete unit and ONE of the two pads. Bastards.

jonnybgood

Here is link to the tensioner and pad. You can buy the pad separately for 5-10 dollars. We haven't agreed here on rennlist about whether to change the tensioner or just the pad. It is the pad that becomes hard and brittle and fails. Nobody has reported a tensioner failure. Porsche never set a replacement interval for these parts. the consensus here on the list is 100k miles and you are definetly taking a big chance. Some replace every 30k miles just to be safe. At 80k I think you are due.

http://www.paragon-products.com/prod...105.049.01.htm

edit: yeah, Peckster is right, only the top pad is available without the tensioner. The bottom pad does not wear nearly as much as the top pad and some replace only the top and leave a slightly worn bottom pad. To my knowledge nobody has reported a bottom pad failure.

ckathens

Tim-

Welcome! Good to see another Bay Area 944 owner. I'm sure we'll meet at one of these GTGs..