I just bought a used '03 350Z. I believe it's the performance package, with Nav.

I have the car in the shop right now being serviced as part of the purchase agreement. One of the issues I was hoping to have them look at was the car's decceleration.

When I take my foot off the gas, there's about a half second delay before the car just kinda sputters- almost like I'm lugging it. It's very frustrating for around town driving. I can't take my foot off the gas without the car lurching.

The service tech says this is normal, and part of the car's "performance package" features. Is this true? If so, is this related to the VDC, and will shutting it off stop this from occuring?

Before I bought the car, I drove a brand new base model Z, and don't recall this occuring. Any help would be appreciated. Thanks!

 

It's not normal if it's the way you're describing it. Your service tech is full of bull, go somewhere else.

 

You'll know when VDC kicks in. Try powershifting from 1>2 at redline, it will kick in, you will get the light that says "SLIP" blinking, and it will make the car go slower by cutting fuel for a second and possibly applying brakes for a second.

It sounds like you're talking about typical engine braking...like when you're in first gear in a parking lot. You accelerate, and when you let off the throttle it feels like you're being pulled back somewhat jerkily.

What cars did you have before this, and were they MT?

 

So what would normal be?

 

2001 S2000, MT (obviously), 2000 Ford Mustang GT, MT.

None of the other cars had this so pronounced. It doesn't feel typical to me. It feels unnatural, really.

 

So, in which gears do you experience this issue?

And at what RPM range?

 

I would say it's most pronounced in second, and gets less pronounced with each successive gear.

Usually between 3000 and 1900 RPM.

If I cruise through my neighborhood in second, and take my foot off the gas, after about a half a second the car kinda sputters, and usually quite strongly.

 

I should also note that the service tech suggested just shifting to third and cruising at a much lower RPM rather than 2nd through a residential neighborhood... right around 20-30 mph.

Maybe it's just from driving the S2000 for so long, where in lower RPMs it was very finnicky, I have grown accustomed to higher RPMs. I will say that the Z is great torquewise in comparison to the S2000. Maybe I just need to ease up a little bit, I dunno.

 

Check your differential mounts!! There are three, one on each side of the diff housing and one at the opposite end of the driveshaft. Use a torque wrench and wrench it down pretty good. Mine had a problem kind of like that too, but it went away after torqueing down those mounts. Do it before your bushings go bad from all that tweaking!

 

I'll suggest that. Thanks!

 

The other issue with the car was a bad bearing in the rear end that caused a clicking when you started moving, so they apparently had to disassemble the rear axle in order to do so.

I would imagine they would have to retighten the differential mounts upon reassembling the rear axle, or am I totally off?

You'll have to forgive my mechanical ignorance. I just drive the thing

 

The car might buck if you're in a low gear and not giving it enough gas. For me it's worst when deceleratiing down below 10mph in 1st or 2nd. It's super touchy.

But it sounds like your issue is something different.

 

I dunno, it sounds like typical engine braking to me. I could be wrong, and you should definitely have it checked out.

Couldn't hurt to replace the tranny and differential fluid.

 

I hear so many Zs clicking when they first take off, I mean even new ones at the dealership. I wonder if this is a different clicking than the rear axle issue?

Almost sounds like it's coming from the clutch. Does the Zs cluth have a rotating bearing assembly? So when the clutch is disengaed and then reengaged, you're hearing all the bearings click in to place maybe?

 

Yeah, I have that weird clutch clunking noise... everyone at the santa barbara meet in socal was telling me it's normal.

It doesn't seem to interfere with performance whatsoever... it basically happens when decelerating in gears 1 or 2 and I put the clutch in.

 

I dunno, it sounds like the same thing to me, and they (my dealership) claim they can fix it.

I still wonder if the diff mounts will need to be retorqued down after repairing the axle issue.

 

I agree. I think it is just the sensativity of the car in 2nd gear when in the low RPM range. I mean he said 3000RPM and then half a second it bogs well it sounds like the RPM is dropping down to under 1000 RPM by then and it will be really touchy. My best guess as to why he isn't used to it would be that the S2000 doesn't know what torque is and the Mustang GT has a REALLY heavy flywheel that causes the RPM to fall much slower than in the 350Z.

 

I hope that's all it is. I didn't notice it in a brand new one, however.

 

That makes sense - I remember from driving a few Hondas that it seems like they have no power until the high RPMs... and the lighter flywheel would make the engine braking seem to kick in suddenly.

 

Yeah, I have that too.