Strange acceleration issue - any ideas before I go to the dealership?
 

Hi,
I have a 2009 370z with 9000 miles on it. Recently, I noticed that in 5th/6th gear, I get "acceleration lag" if I stomp on the gas pedal. The engine revs for about a second (feels like the clutch isn't engaged) and then the car will then "catch" and jump forward. The clutch isn't stiff or clunky and this doesn't seem to happen in lower gears.

Ideas? I hesitate to take it to the local dealership because they're extremely shady and have needlessly cost me money in the past. Hoping this isn't a major fix?

I bought the car in August of 09 so it should still be under warranty, right?

Thanks folks.

Sounds like your clutch may be slipping, though it is hard to tell based on the description.

Yeah that's what it feels like but the car only has 9k miles on it so that seems really unlikely. I guess I'll have the dealership take a look at it and go from there.

Only 9k is irrelevant! People have smoke their clutch in a couple hundred miles.
If it's the clutch? Warranty may not cover it as it's a wear and tear item. Good Luck :tiphat:

I will assume manual, so yes, that sounds like clutch slip. That's surprising since you're in 5th and 6th. I would get that checked immediately.

Yeah it's a manual. Well that's not good.

If the dealership won't cover it under warranty, I'll probably have it done elsewhere since I've heard horror stories of dealerships charging ~2k for a clutch replacement.

you could also go to a different dealership, you don't have to go back to the same one you got the car from.

Depends on why the clutch failed. Nissan has goodwilled a lot of clutch replacements on the 370z's, as well.

Yeah there's another dealership in the next town over. I'll give them a shot tomorrow after work.

Appreciate the advice.

Definitely sounds like clutch slip. It's more likely to happen in higher gears. If it's just worn down from misuse the dealer is going to hook you for the money.

Depends on what they quote me. I'll see what the guy says. If he comes back with some ridiculous price, I'll take it to a local import shop and have it done.

yeah, its much likely to happen on the lower gears. This happened to my brother s2k. Hopefully its a minor problem

If you do not experience this in lower gears (1st,2nd,3rd) than your clutch is fine. This car is a drive by wire throttle body. The lower the rpm's the more lag you will have. If it grabs hard in the lower gears you have a different probelm

He makes it sound like the lag is pretty significant. Drive by wire or not, he's still in a manual tranny car and it should be rather responsive.

If the engine revs but the car doesn't surge forward immediately, it's something in the driveline...most likely culprit is the clutch.

this happens with my AT too.

if I suddenly stomp on the throttle in 4th or 5th it revs about 500 higher stays there for a second not accelerating and then the revs drop back down and it starts accelerating.

mostly happens around 2000-3000 revs

actually to test if the clutch is beginning to slip, testing in higher gears is better.

my old clutch i could drive around low gears fnie, but I could not go full throttle in 5th gear (highest gear for that car) it would slip.

So, yes i would definitely say its the clutch.

also wearable items are covered for 12k miles under warranty against defects, not against wear though.

I'm going to claim it has never worked properly (probably won't fly but worth a shot). About to leave for the dealership. Wish me luck.

Verdict: Took it to a guy I know who worked for Altered Atmosphere and now works for a dealership. After a 20 minute test drive, he told me there's nothing wrong with the car. The tach was only spinning to about 5k before it grabbed. He said this is normal behavior that is regulated by the computer.

Told me if he was wrong, they'd definitely cover it under warranty and to call if the car got "squirrely".

Had other things to do with my tax refund anyway - w00t

^WTF?

If I'm in 5th or 6th gear and floor it, the car surges forward at the same time as the RPM starts to rise. If your RPM jumps and the car has a delayed surge forward, you have a problem. There is no computer interaction happening there. If the revs went to 5k rpm in 5th gear and there was no slipping in the drive-line, you'd be doing over 130mph.

:iagree:

If it gets worse, I'll take it back. At least I have a shot at getting it fixed for free this way.

I should mention it's not "lurching" - it just revs for a second and grabs. I dunno, I may have been overreacting.

.....utter horseshit. The computer "regulates" a clutch to not engage for a moment? Why on earth would they even want to do that?

There's lots of help and speculation on these replies. It might help to post a short youtube video of your speedo & tach (with radio off, so we can hear the engine).

my 2cents.....

:iagree:

Yes a video is needed to help us know for sure what is going on =)

Um.. I would suggest not having him ever do anything on your car as he sounds like he doesn't know what he is talking about unless you aren't issue isn't what it sounds like you are describing to us.

This.

it def doesnt hang for a second before "catching" unless your foot is on the clutch...

yeah I'll try to take a video. Thanks for all the help.

Note to self: Don't go to Altered Atmosphere for tech help

sounds like clutch slip to me...

And clutch slip usually starts on the higher gears and work its way down. This is due to increased load in the upper gears.

This sounds like the perfect time to upgrade to an aftermarket clutch! I want this one.

soo wait if this is clutch slippage, why is this happening to my AT too.

yours is not clutch slip. Yours just sounds like your ecu adjusting to your driving style.

dmhenderson, do you ride your clutch or have some reason to suppose you are too hard on the clutch? If so you may not have a warranted item. If not perhaps it is another conundrum that is warranted. Good luck.

no to get off topic what is a drive by wire throttle body? newbie sorry

The throttle is controlled electronically, No Wire Cable is used like in older models

regardless of throttle setup, it doesn't explain why a mechanical manual clutch would not engage when it's........well, engaged. :D

Owe you guys a beer:

On the way to the airport on Tuesday I floored it in 6th to move into the fast-lane and the clutch utterly failed (car redlined, didn't re-engage until I let off the gas). Horrible burning clutch smell filled the car. Slippage in all gears even with steady pressure on the gas.

Dropped the car back at the dealership last night on the way home.

They're replacing the clutch and flywheel under warranty.
Booya.

To answer various questions
-I haven't been overly rough on the clutch but starting too fast in 1st has caused the clutch to slip since I bought the vehicle.

-I got into the habit of engine braking - especially in bad weather or if I had the need to stop really suddenly. Apparently this is hard on the clutch.

-Dealership can't explain what happened. They believe it has been faulty since day 1.

Anyway, tl;dr:
-My initial suspicion proved correct. If this happens to you, your clutch is about to go and you should take it to a shop immediately.

Heh, Altered Atmosphere was shut down last year/maybe 2 years ago after a rash of customer complaints and rumors of other shady activity (I forget what the deal was exactly). Now they own a R&D project shop mostly focusing on GT-Rs but if I remember right, they had a pretty sick 370z project car working too.

Anyway, at least the dealership was true to its word and is replacing everything under warranty. Really nice to see a dealership stand by their cars like that. Rare these days. One of the reasons I'll continue to buy Z cars.

Here's one of their project cars. Just look at this thing:

YouTube - AAM 370Z Twin Turbo: 500RWHP/372RWTQ