Random "semi-rough" idle while stopped at red lights?

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DarkMan2555
Posts: 14
Joined: Sun Mar 19, 2017 8:06 pm
Car: 2006 Infiniti G35 Sedan 5AT w/ 157k+ miles
Location: Florida

Random "semi-rough" idle while stopped at red lights?

Postby DarkMan2555 » Wed May 03, 2017 2:57 pm

Hi everyone, yesterday I noticed that my 2006 G35 sedan was idling weird, as if there was an ignition or fuel problem. What my car does is when I am slowing down for a red light (or stopped at a red light), once the rpms drop below 1000, the engine "shudders" for a very brief moment, less than half a second. Another way I can describe this "shudder" is what lawnmowers do when they idle, they have those brief moments where they don't run like they should. The number of times this happens when stopped for a red light can be anywhere from 10 - 25. Just this morning when I was stopped for a red light, the engine "shuddered" 23 times in a 2-minute period. The car has 145,6XX miles. Anybody know what this could be? No check engine light and no codes when scanned with an OBDII reader. :confused:


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telcoman
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Car: 2016 Q70 Bye 2012 G37S 6 MT w Nav 94444 mi bye 2006 Infiniti G35 Sedan 6 MT @171796mi. 2013 Altima 2.5SV
Location: Central NJ

Re: Random "semi-rough" idle while stopped at red lights?

Postby telcoman » Fri May 05, 2017 10:53 am

Dirty air filter?

When is the last time you changed it?

Telcoman

ca18det_boy
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Re: Random "semi-rough" idle while stopped at red lights?

Postby ca18det_boy » Fri May 05, 2017 2:37 pm

I've had this same situation happen. Its not regular enough for me to be seriously concerned with it, but I'm investigating it.

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raremotive
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Re: Random "semi-rough" idle while stopped at red lights?

Postby raremotive » Fri May 05, 2017 8:45 pm

I had same issues with low idle. I bought a can of throttle cleaner and MAF cleaner. I sprayed and wipe the throttle clean of carbon buildup, and gave the MAF a good clean with the spray. Now it runs at higher idle as it should.

I also spent the time to re-torque all the plenum bolts.

DarkMan2555
Posts: 14
Joined: Sun Mar 19, 2017 8:06 pm
Car: 2006 Infiniti G35 Sedan 5AT w/ 157k+ miles
Location: Florida

Re: Random "semi-rough" idle while stopped at red lights?

Postby DarkMan2555 » Sat May 06, 2017 4:21 pm

telcoman wrote:Dirty air filter?

When is the last time you changed it?

Telcoman
The air filter is not dirty. I don't know the last time it was changed since I bought the car used in mid-March of this year and it wasn't very detailed on the CarFax.

DarkMan2555
Posts: 14
Joined: Sun Mar 19, 2017 8:06 pm
Car: 2006 Infiniti G35 Sedan 5AT w/ 157k+ miles
Location: Florida

Re: Random "semi-rough" idle while stopped at red lights?

Postby DarkMan2555 » Sat May 06, 2017 4:32 pm

raremotive wrote:I had same issues with low idle. I bought a can of throttle cleaner and MAF cleaner. I sprayed and wipe the throttle clean of carbon buildup, and gave the MAF a good clean with the spray. Now it runs at higher idle as it should.

I also spent the time to re-torque all the plenum bolts.
The idle is not low, the idle is actually high; it idles at 875 rpm when the car is up to operating temperature while in Drive with the A/C on. In Neutral, the idle is around 950 rpm. I took the intake tube off to re-torque the valve cover bolts to help slow down the oil leak and I believe I cleaned the throttle body. I didn't clean the MAF sensor because it didn't look dirty. Maybe I should clean it and see if that makes any difference.
I'm surprised that no one suggested an engine mount causing the engine to shake. The passenger side mount has fluid leaking out of it, which I think is what is causing the car to shake.

DarkMan2555
Posts: 14
Joined: Sun Mar 19, 2017 8:06 pm
Car: 2006 Infiniti G35 Sedan 5AT w/ 157k+ miles
Location: Florida

Re: Random "semi-rough" idle while stopped at red lights?

Postby DarkMan2555 » Sat May 13, 2017 1:15 pm

Hi everyone,

Just an update, today I received an engine mount for my G35 and I will probably swap it out tomorrow. I will let you all know if this fixes my issue with the "semi-rough" idling.


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