engine harshness at high revs

tbonesteak

I took my maxima in for 60k mile service this weekend and spoke to a master tech at the dealer. He stated that the vhr motors' vertically rotating components of the vvel system is what was causing the harshness. Vertical as in components that rotate with the axis pointing in horizontal directions. He said that the vvel system has some imbalances to deal with at high rpms. He said it's the nature of this engine and stiffer mounts will help but only at high rpm operation. Don't know whether or not to believe him but he WAS the master tech. Hope this helps.

need4speed

If I didn't want harsh n course and boominess n road n engine noise?
But be trying to buy an acura or lexus sedan.
Why the F&%K would I want a quiet race car!
And a slightly notchy stick is more fun 2.
F&#k the reviewers. Take the minor criticisms like those with less than a grain of salt.
The Z is perfect fun.

RCZ

Wow.

We aren't talking so much about sound here, its more the vibration at high RPM that bothers some of us I think. Just because its a sports car, it doesnt mean it should feel so coarse and out of control at high RPM. We go back to the same point over and over... and the fact of the matter is that an engine that is made to rev high and for sport driving should be MORE well balanced and exhibit LESS vibration. The engine internals are put through so much more stress, being a sports car and all, that it should be a LOT smoother to aid in its longevity.

Does that make sense to anyone else or is it just me being crazy?

Modshack

You're on the money....Coarsness bothers me. When an engine revs smoothly to redline it feels like everything is working in Harmony. Too bad it's not as good as the Hyundai Coupe in this regard. Certainly not as nice as my last Boxster. I tend to short shift at 6K as a result...

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iwantone09

i am heavily considering a 370. i've driven 3 370z's, first, a manual, then an automatic and then i went back and drove another manual. the reason i keep test drving them is because i needed to see if the rough engine and vibration in the shift knob was just in the first car i drove or was it a traight with all of them. when i first drove the car, i noticed a slight vibration in the shift knob of the manual. i honestly thought something was wrong because of the vibration i felt in my hand. that vibration disappeared with the auto. so i went back today at lunch and drove another manual and sure enough, i felt the vibration in my hand again. i could probably deal with it, but it would take some getting used to. as far as the engine, i didn't feel any vibration in the steering wheel or car, but all of them sounded rough when accelerating. it didn't purr like that g35's did when they came out. i currently have an 08 honda accord v6 coupe with a 3.5 motor. although my car has less power and torgue, my car is much smoother than the 370z. one of you guys talked about the size of the engine possibly beeing a culprit. based on what i've read, nissan probably should have kept the engine at 3.5 liters to keep the vibration down witout having to add so much counter balance. i don't know. i love the 370z and it's still on my list right now, but i will admit that coming from my silky smooth vtec v6 and drving my boys' bimmer 335, going to that rough engine would play heavy in my decision process. it's still a hell of a car though.

VTalumni

I am more concerned with the reliability of the automobile than the feeling when it is vibrating harshly. I mean is it going to shake things loose, destroy the engine prematurely, ruin the mounts, etc. Whether or not it is covered under warrenty, it would still bother me. You all think that is a concern?

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need4speed

I c wat u r saying and u do have a point. But one thing u first year buyers don't realize is.
Though the vq 37 is proven in the G37. Its still mated to a seperately programmed ECU,
New suspension and other components. So these parts are tested in pre production
But production brings forth new issues that must be resolved from the line up.
But guess who are the final testers??? First year buyers.
Cars like this are usually better bought the 1st year by serious tuners or people that don't drive fast but wanna sports car for show.
Reason being tuners will observe problems but they don't care too much cuz they are always trying to make the car better than production. And. Mild drivers. Well. They never put hard enough work in sports cars that they don't need max performance.
But in betweeners. Meaning, you might track here and there. Have a spirited driving style
And will use this car as a daily but. Won't go past suspension n bolt ons. Don't wanna void warranty. Will not do or are interested in tranny tuning or aspirating the engine.
I would suggest. WAIT FOR THE 2ND YEAR MODEL.
AND EVEN THEN. WAIT TILL UR TRUSTED MAGAZINE GIVES REPORT.
Its very common for 1st year cars to exhibit crudeness or harshness. 2nd n 3rd year cars are vastly improved. And the 4th year refresh is usually the sweetest.
I know some of you couldn't wait to get one and an extra year is long.
But tuners report back to companies n companies make fixes.
Novice racers win in year 2.

RCZ

You are serious?

Modshack

LOL.....

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RCZ

^ a little actually. I have a feeling the added stress will somewhat shorten the life of the engine. It just doesn't "feel" right. Oh well, I care, but not that much... Im pretty used to it already and if anything it helps me save a little gas.

tbonesteak

Yesterday i drove 3 different Zs in a continuing effort to pick one up as soon as possible. I'm noticing via these testdrives that dealers have 1 dedicated test car to let customers really experience the Z which is awesome. I have to admit that it's a case by case scenario. I paid EXTRA attention to certain aspects of the testdrive i.e., oil temps, vibration, tranny/drivetrain noise, etc. One of the cars vibrated significantly more than the other 5 i've driven in total. This one was vibrating so hard that it felt a bit painful to keep my hand firmly on the shifter at redline. I did this over and over with identical results. It does feel a bit weary regarding the long term outlook but if a ton of people's motors are dying at 80k, i think at that point we can set up something to approach Nissan. It was very interesting on this one tho. It wanted to explode!! hahah but in some weird way i like it!!!

Mr. C

I can feel some minor high rpm vibration from my G37 which is an auto. I'm guessing the heavy torque converter quells most of it. Definitely the biggest and only real weakness of these cars, the engine is 50 lbs overweight and poor NVH control. Nissan should have redone the VQ engine altogether from the ground up like Toyota did with their GR motor. Honda's J-series engine is super smooth and sounds nice but makes no power. Both Nissan and Honda need new V6 engines not anymore half-assed updates. With Honda you get no power and with Nissan you get tons of vibration, too much weight and a lack of power at lower revs. But with Toyota you get smoothness, peak power, a fat power band and lightweight construction.

Of course Nissan went ahead and built a completely new V6 engine exclusively for the GTR but apparently it is too much to ask from Nissan to give the people who actually pay their bills for an engine that doesn't thrash around. My friend's BMW M3 is completely smooth regardless of engine speed even up to its 8000 rpm redline.

And Porsche's new active engine mounts use magnetorheological fluid, I believe its a world's first.

VTalumni

But you also pay a lot more for the GT-R. Of course, you also get much more of a car from suspension to engine. I am definitely not using that as an excuse for Nissan because I believe that for 30k+ you should have a smooth running engine.

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tbonesteak

How is the vq37vhr an half assed update? so VVEL which is a brand new technology that no other manufacturers use is an half assed update? I don't understand your logic. Find out how many parts on the 370 are different than that of the 350.