# Idle problem solution



## frenchhorn1 (Sep 4, 2006)

Okay folks,

If you are like me, and your altima's idle is bad/shaky, then look here.
Here it is:
Nissan Technical Bulletin No.NTB93-117

Take this bulletin to a nissan dealership and hand them this information written down on paper.

"The Altima’s 2.4-liter 4-cyclinder engine has had problems with a rough idle (vibration) which is transmitted through the steering wheel, seat and floorboards when the transmission is in drive and the brakes applied. There’s a detailed idle speed adjustment procedure which has eliminated the condition on a number of vehicles, and this needs to be performed by a qualified technician"

I hope this helps.
Enjoy!


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## MickeyKnox (Jun 17, 2006)

so will this all be fixed for free?


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## frenchhorn1 (Sep 4, 2006)

MickeyKnox said:


> so will this all be fixed for free?


no. you'll probably get charged an hour of labor.
I took my 97 altima in with that bulletin number, and they pointed out that I should get my engine mounts fixed first. You may want to have your engine mounts fixed. My brother's 99 altima had problems with that too.


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## Leuthesius (Sep 7, 2006)

This apply for the 5spd transmission too?


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## frenchhorn1 (Sep 4, 2006)

Leuthesius said:


> This apply for the 5spd transmission too?



You got me. That is a question for the dealership's service department. Please post what the dealership says. You may want to have your distributor looked at. I've read that the distributor could be causing the shake. Have the engine mounts looked at. I am getting all 4 of mine swapped out for $400.


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## Darktide (Jul 29, 2004)

your distributor could be doing it but the more common problem for all of this (and this service bulletin looks to be just a cover up of it) is a vacuum leak. Normally this occurs in the intake gasket. Turning your idle up a bit will only compensate for the problem until the leak gets worse. This is not always the case but the easiest way to test for this problem is to spray carb clean around the intake manifold when the idle is "rough" and if it smooths/evens out at any point then you have an intake gasket leak at that point that it smoothed out (test a few times at that spot to make sure that its correct and wasn't just a smooth spot in the idle). Unfortunately with our motor it seems to be a fairly common problem as is the oil in the distributor cap, but that'll cause some rough idle, bad driving and then quit altogether on ya. I hope this helps you out a bit.

Darktide


EDIT: its highly unlikely that this specific bulliten deals with manual transmissions because of the use of the work "drive" normally if a TSB is meant to include both transmissions it will use the word "gear" because there is no drive on a manual tranny. But this problem does occur with both types of trannys.


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## Leuthesius (Sep 7, 2006)

frenchhorn1 said:


> You got me. That is a question for the dealership's service department. Please post what the dealership says. You may want to have your distributor looked at. I've read that the distributor could be causing the shake. Have the engine mounts looked at. I am getting all 4 of mine swapped out for $400.


I managed to do all of mine but the transmission mount myself for less than $150. You can get the mount on the passenger side for $50 at Autozone or Oreillys. The others are $20 & $30 respectively (ish).


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## erik2282 (May 17, 2005)

Darktide said:


> the easiest way to test for this problem is to spray carb clean around the intake manifold


my altima shakes on idle, too. and the rpm is not steady. i changed out all my motor mounts and tranny mount last summer.

so I spray where the manifold meets the head, or where the manifold meets the throttle body? or both? is there other things that can cause the vibration? vacuum hoses all checked out. the freakin shakin of the steering wheel is annoying as crap....


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## tman49 (Apr 12, 2009)

Hey what did you end up doing for your nissan to fix it. Mine is having the exact same problem, at idle the rpm's jump around and the steering wheel shakes an all that crap.


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## AltimaBlue (Apr 8, 2010)

I have a 2005 Altima with this problem...as far as I know, wasn't the engine basically the same from 1993-2006?

If that's the case, do you guys think this will solve my issue with vibration at idle? It goes away when I shift the transmission into neutral. This is an automatic, 2.5s, 4cyl model with 98k.

Thanks for any help 

Apologies for bumping a post that's 4 years old...


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## mrrogers (May 17, 2010)

Hey AltimaBlue,
I saw your post about the idle problem. What I have been informed about is that this idle problem is due to the electric fuel pump. This pump pressurizes the system at a certain psi. As the car gets older this pump does not put out the same psi in the system. So the car runs fine while driving but when at an idle the pump now does not put out enough pressure which causes the idle to fluctuate and the motor to shut off. 

The fix is to replace the fuel pump.


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## lintocs (Jun 4, 2010)

*Fuel pump? Seriously?*



mrrogers said:


> Hey AltimaBlue,
> I saw your post about the idle problem. What I have been informed about is that this idle problem is due to the electric fuel pump. This pump pressurizes the system at a certain psi. As the car gets older this pump does not put out the same psi in the system. So the car runs fine while driving but when at an idle the pump now does not put out enough pressure which causes the idle to fluctuate and the motor to shut off.
> 
> The fix is to replace the fuel pump.


Has anyone fixed the problem this way? This "solution" doesn't make the most sense to me, since the fuel pump runs at the same speed/PSI all the time (doesn't it?) and excess fuel comes back to the tank via the return. If there was a problem with the fuel pump, it seems to me you'd see a problem at high RPM, not at idle, and that problem would be massive.

The service bulletin is an adjustment to the A.A.C. valve to properly set the base idle. This makes sense, as everyone with the problem also sees some odd variation in idle speed or smoothness.


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## joyosnow (Oct 26, 2010)

where can I find a copy of this TB?
Thanks


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## lintocs (Jun 4, 2010)

joyosnow said:


> where can I find a copy of this TB?
> Thanks


This thread is really old.

If you've got the really bad vibration/near stall at idle with the transmission engaged on the Nissan KA24DE (2.4L 4 cyl) engine, particularly if your computer throws the cylinder 3 or 4 misfire code (whether or not the "service engine" ligth comes on), you almost certainly have the intake manifold gasket leak Darktide is talking about.

This ASSUMES the vehicle is otherwise in good repair. If you've never replaced a spark plug or wire, distributor cap or rotor bobbin, fuel or air filter, I'd start with those things.


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## joyosnow (Oct 26, 2010)

I did replace spark plug and wire, distributor cap and rotor, fuel/air filter, EGR Valve and intake manifold gasket, however, the problem is still there. the RPM vibrates and engine shakes, sometime knocks.
I am wondering if the TB NTB93-117 will help?
Thanks for your response.



lintocs said:


> This thread is really old.
> 
> If you've got the really bad vibration/near stall at idle with the transmission engaged on the Nissan KA24DE (2.4L 4 cyl) engine, particularly if your computer throws the cylinder 3 or 4 misfire code (whether or not the "service engine" ligth comes on), you almost certainly have the intake manifold gasket leak Darktide is talking about.
> 
> This ASSUMES the vehicle is otherwise in good repair. If you've never replaced a spark plug or wire, distributor cap or rotor bobbin, fuel or air filter, I'd start with those things.


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## lintocs (Jun 4, 2010)

joyosnow said:


> I did replace spark plug and wire, distributor cap and rotor, fuel/air filter, EGR Valve and intake manifold gasket, however, the problem is still there. the RPM vibrates and engine shakes, sometime knocks.
> I am wondering if the TB NTB93-117 will help?
> Thanks for your response.


Are you getting a cylinder misfire code?

I'm thinking bad injector (getting a code) or engine mount (no code).


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## davidwilsoon (Oct 31, 2010)

joyosnow said:


> where can I find a copy of this TB?
> Thanks


If you've got the really bad vibration/near stall at idle with the transmission engaged on the Nissan KA24DE (2.4L 4 cyl) engine, particularly if your computer throws the cylinder 3 or 4 misfire code (whether or not the "service engine" ligth comes on), you almost certainly have the intake manifold gasket leak Darktide is talking about.


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## drplc3 (Dec 17, 2010)

mrrogers said:


> Hey AltimaBlue,
> I saw your post about the idle problem. What I have been informed about is that this idle problem is due to the electric fuel pump. This pump pressurizes the system at a certain psi. As the car gets older this pump does not put out the same psi in the system. So the car runs fine while driving but when at an idle the pump now does not put out enough pressure which causes the idle to fluctuate and the motor to shut off.
> 
> The fix is to replace the fuel pump.



The service bulletin is an adjustment to the A.A.C. valve to properly set the base idle. This makes sense, as everyone with the problem also sees some odd variation in idle speed or smoothness.


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## c7scayman (Sep 19, 2011)

2001 Nissan Altima SE 2.4 KA24DE AUTOMATIC

Okay, I replaced the sparkplugs, wires, distributor cap and rotor, fuel filter, air filter, did an oil change with oil filter change of course. 

Idles very rough whether in Neutral or D or R. RPM drops as low as 500rpm and then it turns off. Even in Neutral, although it rarely happens in Neutral and mostly happens when the car is in Reverse or Drive at idle speeds.

We took it to two mechanics and they could not figure out what is wrong. They said exhaust+gasket is fine, timing is good, O2, ICV is good. 

The first mechanic just said all he noticed was a bad engine mount.

The second mechanic said all he noticed was that Cylinder 2 had 30% less compression than the other cylinders. But he said it has nothing to do with Vibrations. And he noticed oil on the power steering pump and belts, which occasionally causes squeeky belts while driving or when I turn A/C on, but he did not know where the oil came from. 

CEL reads "Random Multiple Misfire"

Does everyone still recommend to follow the bulletin in the first post on this thread?

Also, when I turn left, there is a whining noise from engine or transmission idk, louder as I step on the gas pedal. Could that just be the bad Mount that is causing that noise?


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## wizkid1 (Feb 28, 2012)

joyosnow said:


> where can I find a copy of this TB?
> Thanks


Sorry For bringing back an old thread but for searching the fourms sake i think this should be in here.

*Classification:
EF&EC 93-007

Reference:
NTB93-117

Date:
August 5, 1993

Altima Idle Vibration

APPLIED VEHICLE: 
1993 Altima (U13)

SERVICE INFORMATION
Some automatic transmission-equipped Altima's exhibit an idle vibration (rough idle) which can be felt through the steering wheel, seat, and floor. Such idle vibration (rough idle) may be most apparent when the engine is warm, the transmission is in "Drive", and the brake pedal is depressed while stopped in traffic. The idle adjustments indicated will eliminate this condition for many vehicles.

SERVICE PROCEDURE

1. Being with the following conditions:^ Ignition Timing @ 20 +/- 2 degrees. 
^ Engine temperature in "Normal" range. 
^ Air Conditioning and Headlamps in the "off" position. 
^ Shift lever in the "neutral" position and the engine idling. 
^ Parking brake engaged.


2. Using CONSULT:^ Select "A.A.C. VALVE ADJ" in "WORK SUPPORT" mode. 
^ Touch "START"



OR, without CONSULT

^ Disconnect the Auxiliary Air Control (A.A.C.) valve harness connector.



3. Adjust the base idle speed at the AAC Valve to 687-700 RPM using a screwdriver.

4. Using CONSULT:^ Touch "Back".


Or, without CONSULT:^ Reconnect the A.A.C. valve harness.



5. Put the transmission in the "Drive" position and, using the mode screw, adjust the idle speed at the electronic control unit (E.C.U.) to 687 RPM 

NOTE: The E.C.U. is accessed by removing the finisher on the center console, by the gas pedal.

Then, check for idle vibration. If an idle vibration is felt, readjust the idle speed to 700 RPM.

6. Confirm that the idle speed is 750 RPM or less in both the "Park" and "Neutral" position. If the idle speed is over 750 RPM, readjust the E.C.U. with the transmission in the "Drive" position and recheck, again.

NOTE 1: Ensure that there is no booming noise from the exhaust heat shield plate while in "D" and "N" range.

NOTE 2: If the E.C.U. screw is turned to select "Trouble Diagnosis Modes" the idle speed will require a reset, beginning at Step # 5.*


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