So I finally bought a N/a 2+0 auto Z. Buying a TT 5 speed jap spec 2+2 also in a couple days; but my question is: Do these cars have a problem with the engine mounts going hard (when old I guess)? I have bad vibration/hammering which is worse just before 80km. After 5.5k rpm it smooths out to 7k rpm. When the car is stopped & in N or P & revved, the vibration can be heard & felt in the dash & tunnel. The engine mounts and gearbox mount look OK.(Although the right hand one looks a bit tricky to replace.
Check the tailshaft for movement. Quite a common cause of vibration is for the centre bearing or uni joints to be flogged out.
Tailshaft shouldn't be spinning while car is in N or P. Check the crank pulley first. Also listen, do you hear any noises?
Hey mate , I had a similar problem. the fault was the tailshaft. look very closely at the Uni joints+centre bearing. one of mine had a crack in it, this caused the car to viabrate at low speeds/rpm. when the rpm raised the vibration went away. good luck in finding it.
I forgot to mention that the vibration gets less when the motor/gearbox is HOT. I thought engine mount or tranny mount, cause maybe the ex mani's are softening-up the rubber mounts & making the vibration less. You almost want to pull over & stop when first driving up to 80Km's. When the motor is hot it's heaps better; except when you floor it, & it's more of a hammering noise rather than vibration. No noises other than dash & tunnel vibration noise. Would the crank pulley react with heat like I describe? Just hope it's not the tranny. (Has correct fluid filled to the correct level)
What I can see of them on the car, they look good. No splits or cracks. The tranny mount rubber looks near new; but I know once there of the car they can look quite different.
Sometimes it can be hard to see. If you can grab the tailshaft on either side of each universal joint and twist in opposite directions. if they move thats your problems. Move the tailshaft at the centre bearing and feel for any movement. Same with the G-box mount etc. if the mount it broken you should be able to move the back of the gearbox a little bit.
I'm getting lost here. He says that he still gets vibrations and noise when in Neutral and Park. On all of my cars the tailshaft does not rotate when in these positions. I doubt whether it is the gearbox mount, It normally shows wear when in gear. You didnt state whether it was Manual or Auto, if Auto you could have a cracked flexible plate or loose bolts. If its manual it could be the flywheel is loose.
i can see how you might come up with that logic, but the softness or hardness of the mounts probably shouldnt make that much difference, since its also possible to get solid mounts. I have racing mounts in my TT, the mounts I pulled out of the na were in half when the na engine came out. to be honest I havent noticed a difference between the oem and hardened engine mounts. logically, if the driveshaft is spinning, the car will be moving since its directly connected to the diff and without a clutch its not possible for it to spin independantely. so it is most likely something that has been mentioned already. or something is out of balance with the engine
Everything he describes is indicative of numerous posts(over a number of years)which have always come down to an aging/damaged Centre Bearing on the tail-shaft. Do a Search on this item and you will find heaps of descriptions of exactly what you are observing. The reason that the vibration is evident when starting-up and moving the car, is generally due to the rubber "mount" associated with the bearing, being "hard"(having cooled down since previously driven). As soon as this rubber heats up(upon re-starting/driving)it becomes more flexible and vibrations diminish accordingly. This whole process repeats itself EVERY time you re-use the vehicle(until the rubber eventually disintegrates completely). Don't take my word, do a proper SEARCH on this subject and it will become obvious. It should be noted that the symptoms he is describing may well be from more than one problem being present. It's not unusual for several issues to be present at the same time and lack of experience can easily convince you that they are ALL coming from the one source.:zlove::zlove:
On my car when the transmission is in PARK I don't think the drive shaft rotates fast enough to vibrate at the centre bearing.
When your transmission is in "PARK" the drive-shaft SHOULD NOT BE ROTATING AT ALL!!! For the uninitiated, if the drive-shaft turns, the rear wheels will also turn(unless, of course, your Diff is completely rooted).:rofl::zlove:
Sorry missed the part about doing it in park or Neutral. - Is the vibration just as bad in Neutal/park then when you are moving? -How bad actually is the vibration ? ie : can you hear vibrations / rattling ? or just feel the dash vibrate when you touch it? . -If not really bad, it Could possibly be a miss / failing injector? I had 2 injectors reading way out of ohm (32 Ohm and 28 Ohm) and they were causing vibration as two were not firing and made car the vibrate (not as bad as a broken tailshaft though).
Check to see if the exhaust hasn't been hard mounted somewhere or damaged and pushed up against the under body.
Mostly because there have been countless posts on here during the years I have owned a Z32, that describe exactly the same symptoms, e.g. Harshness/vibration at start-up, which subsequently diminishes after driving for a short time(as the rubber heats-up and becomes more flexible). This is mostly due to the rubber sagging during non-use and becoming less flexible with increasing age(yes, we ARE still discussing T/Shaft Centre Bearings). Also, because numerous owners who have been faced with this issue, have completely eradicated it by going to a one-piece T/shaft(no centre-bearing)myself included. "If it looks like a Duck, walks(waddles)like a Duck, it's usually A DUCK!!!!" :zlove:
Chock the front wheels then jack the rear of the car up & put it on stands DON'T trust the jack to keep it up. Then start the car & have a listen for the noise/vibration if you can't find it put the car in first gear & have another listen. As you are a 'newbie' it's always advisable to have a friend there with you just in case. Be careful DON"T get TOO close to the spinning tail shaft. If you still can't find the problem take it down to a reputable mechanic & he'll put it up on a hoist & will be able to have a better look. It's quite possible you may have a bent driveshaft, I think it's called, in the gearbox. If that's the case then get a s/hand g/b. Check the for sale section on our forum. Grahame.
Do not do this [TIS] Putting the rear of the car on quality stands and running it at low revs in low gear is one thing, getting under the car when you do this is quite another. By quality stands, anything that does not have the pyramid four point base is not a quality set of stands and should be binned. IMHO
