# Vibration at idle



## Emery (May 10, 2006)

Hi guys. 98 Sentra GXE, about 100k miles. Runs fine, only noticing that it vibrates a bit more at idle than before. Notice a little vibration in steering wheel, and you can hear minor rattles in the dash. Once you accelerate, it seems fine.

I cleaned the IACV and replaced plugs, wires, rotor, cap, air filter, and PCV valve. Didn't make any difference.

So, is this just something that happens with age, or can I get the smooth idle back that I had when I bought the car at 40k miles? Is it the motor mounts maybe?

Thanks, any ideas would be appreciated.

-Emery


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## jdg (Aug 27, 2009)

Might be getting to be that time where you might need to replace the timing chain tensioners. Check around here you'll find more than one thread discussing them. Don't know if it's causing your vibration, certainly plausible though...
Motor mounts...sure...maybe...
If you've got the money and are into 'recreational maintenance  ', maybe swap out the front O2 sensor for grins. Maybe it's getting a bit slow on the draw.
Stick or automatic?


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## Emery (May 10, 2006)

Thanks jd. It's a stick.

If the timing chain tensioner were causing trouble, would that only show up at idle? Seems it should cause issues at speed as well? As far as I can tell, it's still very smooth while moving.

thanks!


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## jdg (Aug 27, 2009)

Emery said:


> Thanks jd. It's a stick.
> 
> If the timing chain tensioner were causing trouble, would that only show up at idle? Seems it should cause issues at speed as well? As far as I can tell, it's still very smooth while moving.
> 
> thanks!


You would think that..but, if you think about it just a tad bit further...
The engine, specifically the crank is at a relatively steady speed at idle, but it's really not steady. It's getting two power pulses per revolution, and two 'coast' pulses in that same revolution. The crank, hence the timing chain, is pulling the cams along with it. If one side of the chain is allowed to develop just a little bit of slack in it, it'll jerk on the cams, chain will tighten up, cams will catch up, chain will get some slack, chain will jerk on the cams, and so on and so on. So, therefore, your cam timing will change ever so slightly.
At idle, everything is happening so 'slowly', that a person can feel it. At speed, it just might be happening too fast for anybody to feel it. Especially if you've got it in gear and you've got the whole weight of the car, motor mounts, tranny mounts, rubber tires, etc. taking up the vibration for you.
But I'm just guessing at it...I could be 100% wrong also. Does the top of the motor have an irregular clattering to it? Kinda a bit like a diesel? Or like there might be a couple of smallish marbles bouncing around in there, specifically next to your timing chain covers?


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## Emery (May 10, 2006)

Thanks JD. In listening to that part of my engine, it does make the sound you describe. So, looks like I'll be doing the upper tensioner replacement thing.

Hope that solves the vibration!

thanks,

-Emery


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## pulsar86 (Aug 13, 2009)

Check the vacuum hoses are in good condition a lot of idle problems are caused by bad hoses. If you can get hold of a vacuum gauge a good reading at idle is around 22-24 inHg {inches of mercury]. Any bad hoses show up if the reading is unsteady or low.


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## Jopet (Aug 10, 2009)

Hey guys, its about that time of year that Im able to get to work on my car outdoors. Can you give me a good web store that sell the uppper timing tensioner? I've put it off too long and now I will replace it. I search autozone and pepboys, they don't seem to have it. My car BTW is a 95 B14 1.6 DOHC auto . thanks


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## zacward (Aug 23, 2009)

Check out partstrain.com or courtesynissan for nissan parts


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## Emery (May 10, 2006)

Hi guys. OK, I finally replaced the upper and lower tensioners. The upper was ate up, and replacing it eliminated noise in that area. However, my rough idle remains. Car is very smooth at speed, it's just the idle.

I'll check the vacuum hoses, any other ideas?

Another place to get the upper tensioners is O'Reilly Hi-Lo, or Advance Auto Parts. Autozone doesn't have them.

Thanks.


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## pepperjack13 (Jun 20, 2010)

My car (steering wheel) vibrates too but only when the a/c is on (and at idle) is this the case?


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## Faja (Aug 31, 2009)

Emery said:


> Hi guys. OK, I finally replaced the upper and lower tensioners. The upper was ate up, and replacing it eliminated noise in that area. However, my rough idle remains. Car is very smooth at speed, it's just the idle.
> 
> I'll check the vacuum hoses, any other ideas?
> 
> ...


Did you check the motor mounts like jdgrotte suggested?


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## Emery (May 10, 2006)

yeah, they seem ok. I'll check vacuum next.


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