Ultimate solution of Vitz vibration/rattling on idle (beyond throttle body cleaning)

[mgalaxy3]

Many people experience this. But not everyone. Some cars vibrate/rattle on idle randomly, for some time only, some don't at all or it is quite unnoticeable.

What should be done to get rid of it or minimize it, even AFTER throttle body cleaning it's doing it.

So, here are the steps:

1. Clean throttle body
2. What if it still rattles/vibrates on idle, then vibration stops for 3-4 seconds, and starts again.
3. What should be steps 3, 4 etc?

Apart from throttle body cleaning, what else should be checked/cleaned/maintained?

Those who have gone through this and beyond throttle body cleaning, suggest.

[zakiuddin]

Many people experience this. But not everyone. Some cars vibrate/rattle on idle randomly, for some time only, some don't at all or it is quite unnoticeable.

What should be done to get rid of it or minimize it, even AFTER throttle body cleaning it's doing it.

So, here are the steps:

Clean throttle body
What if it still rattles/vibrates on idle, then vibration stops for 3-4 seconds, and starts again.
What should be steps 3, 4 etc?
Apart from throttle body cleaning, what else should be checked/cleaned/maintained?

Those who have gone through this and beyond throttle body cleaning, suggest.

Hook-up an OBD scan tool capable of monitoring misfires. The random-vibration on idle may be a misfire on single or multiple cylinders. Reasons can be:
1. incorrect timing-
2. Spark Plugs or Coils. -->Self evident
3. Incorrect fuel Mixture. --> This bit is interesting. Both rich and lean mixture will end up in misfires.
a. If there is a lean mixture i.e. Vacuum leak, you'll end up in misfires
b. If there is a rich mixture especially due to a leaky injector(now this is interesting), the PCM will try to adjust the mixture by cutting short the fuel supply to all cylinders in that bank ( coz PCM has no way of knowing which injector is leaking) to compensate the unaccounted fuel due to leaky injector.

Note that:
No.1 is not applicable in your case as you mentioned vibration stops for 3-4 seconds
No.2 is applicable only when you have radom or consistent misfire on only one cylinder.
No.3 is applicable when you have multiple misfires across different cylinders and only on idle as the Wide Open Throttle (WOT) will dump more fuel and diminish lean condition.

So next step is to use an OBD tool to see fuel trims, misfires and anything out of usual.

[mgalaxy3]

No.1 is not applicable in your case as you mentioned vibration stops for 3-4 seconds

yeah.. also, when car is driven on highway for some time, then you stop - it usually doesn't vibrate on idle.

When stopped and put in P there's no vibration either.

Doubt it is a misfire.. or still you think so?

[babarhyd]

Ultimate solution is to stop buying JDM scrap.