Jumpy tach?

Vaughanabe13 · 11-26-2011, 09:52 AM

So I've noticed this in my Z and it's a little weird. Under hard acceleration I will sometimes notice the tach needle getting kind of erratic and jumpy. Like it will be increasing and then for a split second it will "stick" and then it will jump up after it gets "unstuck" and it just generally isn't a smooth movement of the needle. When the car starts up the needles all do their sweeps just fine with no jumpy/jerky movements. Anyone else notice this? Am I making something out of nothing here or is this actually a thing.

Red__Zed · 11-26-2011, 06:54 PM

Is your clutch slipping?

MattP725 · 11-27-2011, 01:58 PM

Quote:

Originally Posted by Red__Zed

Is your clutch slipping?

That shouldn't make it "stick" since the RPMS would still jump, infact the tach would race.

I would think that you either have a faulty gauge cluster or a bad engine speed sensor/wire. If it really bothers you, you could try hooking up an external tach to see if you can narrow down the issue to the cluster or the sensor.

fuct · 11-28-2011, 11:58 AM

Quote:

Originally Posted by Red__Zed

Is your clutch slipping?

this or lack of traction. i doubt the tach is bad.

Red__Zed · 11-28-2011, 12:01 PM

Quote:

Originally Posted by MattP725

That shouldn't make it "stick" since the RPMS would still jump, infact the tach would race.

I would think that you either have a faulty gauge cluster or a bad engine speed sensor/wire. If it really bothers you, you could try hooking up an external tach to see if you can narrow down the issue to the cluster or the sensor.

If the clutch is slipping, the tach will often appear to stick after the clutch grabs.

Could also be a bad ground I guess...

m4a1mustang · 11-28-2011, 12:37 PM

Quote:

Originally Posted by fuct

this or lack of traction. i doubt the tach is bad.

If there was no traction the tach wouldn't stick, it'd spike up as the revs would climb when the wheels spin faster...

fuct · 11-28-2011, 04:24 PM

Quote:

Originally Posted by m4a1mustang

If there was no traction the tach wouldn't stick, it'd spike up as the revs would climb when the wheels spin faster...

my comment was only covering the spikes in acceleration. the sticky tach.... got me.. :\

Vaughanabe13 · 11-28-2011, 11:21 PM

Well I'm pretty sure the clutch couldn't be slipping, I mean this car only has 9K miles on it, 4 of which were put on by me. This is my first manual car but surely I didn't wear out the clutch in 4K miles, right? Guess I can't know what the previous driver did to it though, but that seems crazy to me.

m4a1mustang · 11-28-2011, 11:23 PM

I doubt it's clutch related at all.

If you are accelerating smoothly when this is happening and the tach is literally sticking at one RPM while you continue to accelerate it's more than likely some electrical issue.

MattP725 · 11-29-2011, 12:06 AM

Again I am betting on a bad RPM signal coming from the ignition or a bad cluster. If you were slipping the RPMS would race and likely bog back down when the clutch/tires caught. It wouldn't just "stick".

It is very possible to wear a clutch at 9k if it is overly abused, even if not intentional especially if it wasn't broken in properly but I still don't think that is the issue.

Buy or borrow a dirt cheap tach and hook it up and see if it matches what your cluster is showing when you accelerate. I am sure you could find one on ebay for $20 or find your nearest Honda Civic club.

Or even better, if your within warranty take it to the dealer and save your time/money.

Vaughanabe13 · 11-29-2011, 12:58 PM

Yeah, I'm definitely accelerating smoothly and if I weren't looking at the tach during hard acceleration I would never even notice the issue because the car feels and sounds fine under heavy load.

Unfortunately it's about to snow here, so I probably won't be able to investigate this issue until next season. The car will still be under warranty though so maybe that's the best way to go.

11-26-2011, 09:52 AM	#1 (permalink)
Vaughanabe13 Enthusiast Member Join Date: Jul 2011 Location: Iowa Posts: 387 Drives: 09 Nissan 370Z M6 Rep Power: 14	Jumpy tach? So I've noticed this in my Z and it's a little weird. Under hard acceleration I will sometimes notice the tach needle getting kind of erratic and jumpy. Like it will be increasing and then for a split second it will "stick" and then it will jump up after it gets "unstuck" and it just generally isn't a smooth movement of the needle. When the car starts up the needles all do their sweeps just fine with no jumpy/jerky movements. Anyone else notice this? Am I making something out of nothing here or is this actually a thing. __________________ 2009 Nissan 370Z Touring, w/sport, 6MT, chicane yellow/black.

11-28-2011, 11:21 PM	#8 (permalink)
Vaughanabe13 Enthusiast Member Join Date: Jul 2011 Location: Iowa Posts: 387 Drives: 09 Nissan 370Z M6 Rep Power: 14	Well I'm pretty sure the clutch couldn't be slipping, I mean this car only has 9K miles on it, 4 of which were put on by me. This is my first manual car but surely I didn't wear out the clutch in 4K miles, right? Guess I can't know what the previous driver did to it though, but that seems crazy to me. __________________ 2009 Nissan 370Z Touring, w/sport, 6MT, chicane yellow/black.

11-28-2011, 11:23 PM	#9 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	I doubt it's clutch related at all. If you are accelerating smoothly when this is happening and the tach is literally sticking at one RPM while you continue to accelerate it's more than likely some electrical issue. __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

11-29-2011, 12:58 PM	#11 (permalink)
Vaughanabe13 Enthusiast Member Join Date: Jul 2011 Location: Iowa Posts: 387 Drives: 09 Nissan 370Z M6 Rep Power: 14	Yeah, I'm definitely accelerating smoothly and if I weren't looking at the tach during hard acceleration I would never even notice the issue because the car feels and sounds fine under heavy load. Unfortunately it's about to snow here, so I probably won't be able to investigate this issue until next season. The car will still be under warranty though so maybe that's the best way to go. __________________ 2009 Nissan 370Z Touring, w/sport, 6MT, chicane yellow/black.

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11-26-2011, 06:54 PM	#2 (permalink)
Red__Zed A True Z Fanatic Join Date: Jul 2010 Location: window seat Posts: 28,940 Drives: Mostly on two wheels Rep Power: 120	Is your clutch slipping?

11-29-2011, 12:06 AM	#10 (permalink)
MattP725 A True Z Fanatic Join Date: May 2011 Location: Toms River, NJ Posts: 1,904 Drives: 2010 40th Rep Power: 17	Again I am betting on a bad RPM signal coming from the ignition or a bad cluster. If you were slipping the RPMS would race and likely bog back down when the clutch/tires caught. It wouldn't just "stick". It is very possible to wear a clutch at 9k if it is overly abused, even if not intentional especially if it wasn't broken in properly but I still don't think that is the issue. Buy or borrow a dirt cheap tach and hook it up and see if it matches what your cluster is showing when you accelerate. I am sure you could find one on ebay for $20 or find your nearest Honda Civic club. Or even better, if your within warranty take it to the dealer and save your time/money.