I think Nissan designed the Z to be like that. They purposely left out the damper on the 6MT shifter so you can feel the vibrations in the shifter. It is afterall designed to be a 2 seater sports car,
not a Coupe DeVille.

 

I concur that the engine is less smooth than others, and I also feel that it is primarily due to the design of the Z and not the engine itself.

Part of the issue is the shifter linkage, which has very little isolation, and another factor may be the engine mounts.

I don't know how difficult those would be to change, but maybe going to a softer rubber for the engine mounts would help in addition to the suggestions that have already been made.

-D'oh!

 

None of these vibrations bother me. It's a sports car. Besides, I think all that adds up to making the Z feel more powerful.

 

I've been searching the forums trying to find others who have noticed vibration at higher rpms. I first noticed it at a driving school at a long track. I was shifting at about 6000 and getting a buzz all the way up to my shoulder going from 5th to 6th. Having had an M3 before, which was smooth all the way to 7000, I found the vibration to be a concern.
The auto mags all talk about how smooth this engine is so I know what I have is not normal. No V6 is that rough.
Normal shifting to utilize the max torque is around 5200 so there is no good reason to go to 6000. Still I would be interested in knowing if others have had similar problems.
Dealer says it is within specs. shop guy confided they don't know what to do about it unless Nissan comes up with a fix.

 

I dunno about that because lots of guys with 02/03's Maximas are complaining about the same thing over at the org including myself. Like Snolden said once Nissan bored this engine out using the same block it lost lots of its smoothness and several pubs have noticed this on the Maxima and 350 as well.

 

Me three. Turbo 4.3 hehehe

 

Two things:
- As already posted, Porsche's 6 cylinders are flat-6, not inline six designs. Basically, it's almost like a V6 with a 180 angle (but not quite).
- BMW will not move to a V6. The inline 6 has been their gold standard and they make them better than anyone else. As much as they have been doing weird things lately (Chris Bangle), they won't move to a V6. Although they will put V8s in more and more (read cheaper/smaller) cars as the German power wars continue to rage on.

Jason

 

Oops, double post.

 

A thrasher is a good way to describe it IMO. I used to drive an inline 4 (integra Type R), which would rev smoothly to its astronomical redline. Driving the Z at high rpm's is a completely different ballgame. I tend to not rev it up quite as much, because I think I tend to feel like the car is working too hard. If that makes sense...in other words, I feel like the car is stressing out when I'm getting above 4k rpms...when in reality, I know it was designed to rev that high, and it won't be a problem. I tell people all the time that it's rough, but they sometimes disagree.

The design is surely sound, it's just a frame of reference thing. Inilne 4 and 6 drivers will think its lumpy no doubt...others might find it silky. I think it's rough and tumble.

That said, it's still fun. I just need to get a good exhaust on it to drown out the vibration from under the hood. As others have said, it's a sportscar...I'll live.

 

My average driving rpm is about 5K - 6K, in town. Feels good & smooth. MPG about 13.8 in town. Shifting is tight & crisp.

JMS in TX

 

Well, to me the Maxima's 3.5L V6 is pretty smooth, but not THAT smooth. It does sound a little truck-like. I've only ridden (not driven) in a 2000 Max (w/the 3.0L V6) and it did sound smoother than my 3.5L, so yes, I do feel Nissan sacrificed smoothness w/the 3.5 for power.

But since you have access to both, like me, I'm sure you'll agree that the Max is WAY smoother and quieter (not counting road noise) than the Z.

 

Yeah its a little smoother and a tad quieter but neither are as good as they should be.

 

My car seems a little rough, but only at low RPMs....more like the Beretta GTZ i used to drive before the Acura 3.0CL i traded for this Z. The CL was insanely smooth. I do find that my car is actually smoothing out more though with age...i got it with 4K miles and im about to hit 7K and its seems to have loosened up a bit. Also, when i hit it hard from a standstill and move up through the gears changing at around 6600RPM's, the engine seems SO smooth....im starting to think it likes to be run hard rather than to be lugged around!! Is it possible that the engine is still "breaking in" to some degree even with 7K miles? It sure seems to be running better.

 

Oh, deffinately! Mine engine began to smooth about where you are.

You are also correct about the reving. The Z likes to be spun up quickly...it doesnt like to hang around a high RPM for any period of time, as the engine will get kinda buzzy. This I atribute to the engine (big bore) but the rest of the NVH is simpy a trait of the car itself. The engine is very close to the cabin and theres very little insulation between them.

 

I know it's been said, but I'll say it again. The grounding kit really did help.

When I went from a E36 M3 Inline 6 (super smooth) to Z I really noticed the difference. I was the same way, I didn't want to rev it. After I put the grounding kit on, the engine was allot smoother.

 

Where do you get this grounding kit and for how much?

 

I built my own out of 4 guage speaker wire and copper terminal lugs and heat shrink tubing. I built a six wire system. Total cost: nothing, just had the isht laying around. to buy all the stuff is around 40-60 dollars unless you have hookups. YOu will need an industrial strength crimper however, those run 50 dollars and up unless you have an electrician friend. anyone who works with 3 phase ac should have access to the size crimper you need.

 

My last car was an '02 A4 3.0 and the 3.5 in my Z compares vary favorably to the Audi in terms of smoothness. I will admit that there is more engine noise in the Z, but thats what I expect and want to hear from a sports car. The 3.5 revs up smoother and more quickly thatn the Audi 3.0 IMHO. I think the biggest source of vibration is the shifter (which I also like more than the A4) I think that you would really have to part with a lot more cash to get a engine that is smoother than the 3.5 and still get the same type of performance. My 2 cents. Have a great weekend all...

 

Like I6 and V12 engines, I thought horizontally opposed engines were naturally balanced? I saw Jason Bourne posted up above that Porsche's engines weren't quite 180 degrees, so I guess that would make them not 100% naturally balanced. (But darn close.)

Can anyone comment on the natural balancing of various manufacturer's "flat" engines? (i.e. Mainly just Porsche and Subaru now days, but the old VWs had them, too.)

 

ditto for Dr. Greg. The engine doesn't sound rough to me at all. Infact it is a bit too quite. Of course I am kinda old and always owned American Performance Cars (Charger, Vette, Cobra).