Randiscan

Hi,
I have a 2005 GTO with 566 miles on it. I want to know if anyone else experiences a very rough idle. It is almost like it has a miss in it. It drives perfect, it is only when it is sitting and idling. I took it today back to the dealer and they tried to tell me that they all do it. Then they said try different gas. I have filled it 3 times already from different stations and have also put in 93 octane. Nothing makes it better. Does ANYONE else have this problem???? I just want to know if it is normal...it doesn't seem to me that it should idle like this.
Thanks! Any input is appreciated.
Randi

dragcoupe

Hi, my 06 has a slight shake at idle. Its the cam. More cam, gets you more shake, even with wide lobe centers.
Try a cam with 106 lobe centers, it will keep you awake at the light.

Randiscan

Hi and thanks for the response....we actually have a 64 and we understand what the cam feels like when it shakes but this is like a miss....it comes and goes. A cam would be a consistant shake. Seems like it isn't getting enough fuel at idle. But if the dealer feels that it was or is bad gas you know we are not going to win. I thought if other peoples GTO's did this that it was either normal or a problem with many.
Randi

GTO Nation

I have a bit of a 'miss' at idle sometimes, but if your engine light isn't on don't worry. The PCM monitors the missfires by measuring the speed of the crankshaft. If it actually has a miss it will set a light and a code.

Randiscan

GTO nation...I want to say thank-you so much! You made me feel much better. I was thinking I had a problem and I LOVE this car. You all seem very knowledgeable so what your saying makes sense. I just wanted to hear that mine wasn't the only one doing this and of course don't feel like having my car in the shop for what really isn't a problem.

Thanks again!
Randi

wakerider017

First day I brought my car home I got a CEL...

When I first started the car up if felt like it was misfiring horribly...

Dealer said it was a bad crankshaft sensor...

Dealer made it all better in a few hours...

NYTIGER

Its the cam. It will give the car a shake,shake feeling.

Its a musclecar relax.

wakerider017

yup.. ^^^

Thats most likely it... My car a bumpedy bump in!

Just wait til I get my big stick!

N20LS1

You probably have a defective MAF.

HRJ

iTrader: (2)

It's normal. The engine vibrates slightly at idle. This engine isn't sewing machine smooth like a BMW 5 series. It was developed in the "musclecar" vein, and displays some of those characteristics. Don't sweat it.

GTA91

iTrader: (14)

All 3 GTO's I've had, (2) LS1's and (1) LS2, have all had a "shimmy" at idle... its really weird but gives the car an old feel. None of them did it all the time, but sometimes after sitting and idling for awhile they have all done it.

gametech

iTrader: (1)

My '04 does actually have a slight miss at idle if I run at stochiometric(14.7 A/F). If I idle at about 12.5 it is smooth as silk. Of course I also traded my maf for a turbo, and I have 60# injectors now, but it did that stock as well.

Nightclaw

+1 on it being cam-related.

Frankly it amazes me that they put the cam profile they did in these cars. In the early days of the LS1, it would've taken an aftermarket upgrade to get a 204/211 with .525" lift! I expect a little shake from this cam.

Rt66er

Hate to raise this thread from the dead, but my 04 A4 has a rough, vibrating idle... but only when the weather is hot. Not talking about cam shake; this is different. Constant vibration that gets worse as the outside temps rise. Below about 40 degrees, idle is smooth as silk. Over 90 degrees, idle is rough as a cob. If I just rest my foot on the accelerator pedal and raise idle ever so slightly, it smooths right out. BTW, this is only in "D" where idle speed is at it's lowest. M6 folks wouldn't ever see this, cause their engines never idle this low. I think there is something messed up in the stock tune that doesn't allow the engine to adjust properly to higher ambient temps, like maybe it's running too rich or too lean at high temps.

radkon

iTrader: (2)

Check the spark plugs and make sure they are gapped properly. Will made a noticeable difference if they aren't.

imran

its normal, my 05 shakes at idle. Its the cam.

Also your engine isnt even broken in yet, after 5000 miles, your engine maps will change. i thought it was bs at first when i read on ls2gto but its true.
after about 5100 miles or so, your car is be very different.
different as in more power. its awesome.

24v

There is nothing that changes after 5000 miles other than the engine being broken in. I wish people would stop spewing that crap.

Swamp Goat

ditto

TonyGXP

yeah, urban Myth...guys on the SRT site swore to this until one guy posted the numbers on a 300mi motor and they were the same after 3k (their "MAGIC" number)...mine (and my LS4 GP GXP) did feel faster after it started breaking in at around 1k mi, but I doubt it was "That" significant..my friend's AWD TBSS went 13.9 at 4k mi and 13.7 at 7k, but I am sure it's just different weather & other variables..JUST AS LONG AS THEY'RE NOT GETTING SLOWER!!!

oh yeah mine has that intermittent shake at idle as well...gotten better since new (has 2800mi on it now, 5 months old)