[VaerO]

Hey all,

I've got a bit of a concern with the i30. Just marked 32k and for the last couple of weeks the car, when  idling, almost feels like it's shivering. Nothing major but I can notice it when stopped at lights etc... also seems to be worse when the AC is on. Turning the AC off instantly cuts the shiver in half.

Moved from Wagga to Sydney for study so the cars now being exposed to long idles waiting at lights and stuck in traffic. Could it be the car "adjusting" to city life?

I've been reading few similar topics and people suggest a fuel additive to help clean the engine. The cars never had anything but 98 Premium in it whixh I understand already has cleaners in it so will a 3rd party additive  help much?

Thanks guys!!

[eye30]

When it shivers what rpm is it showing with air con on and off?

[Dazzler]

Nice to hear from you. I wouldn't think an additive would be necessary if you have constantly used 98. Hopefully @cruiserfied may be able to set you on the right track. 32k, so you may have had a recent service? Could it have started after that?

[VaerO]

Thanks for the reply guys.

I'll take notice of the rpm when it happens next. I drove to work today but it only takes about  5 minutes to get there so the engine might have been warm enough for the issue to fully show. Usally tho the car idles at around 500rpm, turning he ac on and off makes it go to maybe 510rpm when on?? The needle only moves a tiny bit.

The car did have its 30k service about 3 months ago but everything seemed fine after that.

[Dazzler]

500 rpm seems low? Might be your problem.

[VaerO]

Really? Always sat around 500 when warm. Had to move the car during work to avoid a parking fine and noticed at a cold start it hovers around 1000.

[PhireSideZA]

I've found my rev gauge isn't too accurate - it reads about 100rpm too high in my 2011 FD and plugging in an OBD adapter confirms that it's actually out by a few rpm. Mine idles at ~600rpm, ~630rpm with the AC on.

I too get a shudder especially felt through my gear lever when the AC is on. Could your idling be too low? It feels to me like there is a 'sweet spot' where there are no vibrations at all, but anything lower or higher by a handful of rpm causes it to shudder a bit

Sent from my Redmi Note 2 using Tapatalk

[Dazzler]

Could your idling be too low? It feels to me like there is a 'sweet spot' where there are no vibrations at all, but anything lower or higher by a handful of rpm causes it to shudder a bit

Yep, that was my thinking too... 

[diablo]

I was very surprised to read of a tick-over RPM of 500. I dunno how you adjust them these days but in the days when I could twiddle the screws on the carburettors I'd never set it as low as that.

My OBD reader (a cheap one) doesn't tell me if the rev counter is correct but the gauge seems to indicate that my 1.4 petrol is  about 1100 when cold and drops to 740 or so when warmed up. The tick-over speed doesn't seem excessive to me, similar to all my previous cars.



I don't get no judders.

[Phil №❶]

According to the manual, idle speed is 660 rpm +/- 100 rpm.

[XinZhao]

O have never seen the idling speed reference in the manual, but I can say that I'm shocked that the idling speed can be as low as 500 rpm.

Over the obd2 I can see my Idling speed always sits at 780 +-10(max)
Exactly what the needle says.

[Phil №❶]

We are talking about a petrol model.

[XinZhao]

Oh
Never drove a petrol with rpm-meter..

[Gof]

It may be an air leak in the inlet manifold causing the idle mixture to go lean, a fuel injector starting to play up or a spark plug starting to break down.
If you increase the revs to 900-1000 rpm does it disappear or just reduce a bit?
If it disappears it probably is just excessively low idle speed.

[VaerO]

Sorry for the non reply guys!! 

I'll take note of that next time Gof  and report back, thanks!!   

[PhireSideZA]

Some out of the box thinking but could the Throttle Position Sensor be duff?

[Little Mick]

Injector plug.
Chased the same issue with another if my cars until the plug eventually fell off and then the issue was clear.
While the car ran, the injector pulse was weak as it was jumping a gap.
If it has been an issue since service ring the dealership that did it and tell them you want it sorted.