Rough Idle from Dirty Throttle Body
Safe to keep driving. Fix it when convenient.
Affects model years: 2018-Present
Symptoms
- Idle flutters or hunts between low and normal rpm
- Creep feels jerky at parking speed (CVT surge from idle instability)
- Idle dips when the aircond compressor kicks in
- Slight hesitation when pulling away from a stop
Cause
Carbon and oil vapour deposits build up in the throttle bore and on the butterfly plate and idle air passages. Malaysian servicing guides describe sticky throttle body deposits as a routine Myvi issue in the 40,000-80,000km window, and it is worse on cars with higher idle hours in traffic.
Solution
A workshop cleans the throttle body and finishes with an idle relearn on a scan tool. A spray-only clean runs RM80 to RM120 and often comes back. A full clean with the relearn runs RM150 to RM250. Tell them the idle hunts and dips when the aircond cuts in, so they start at the throttle body rather than the gearbox. Leave the relearn to the shop that did the work. The battery disconnect trick at home is a coin toss, and a bad idle for a week is a poor way to save RM40.
basis not stated · undated
The symptom is easy to confuse with CVT or mount problems. The quick self check: with the engine warm and the aircond on, watch the tach at idle. A steady rpm with a shudder you feel through the seat points at the mounts. A wavering rpm points at the throttle body.
That test costs nothing and it saves you from paying for a gearbox diagnosis you did not need. Do it before you book anything.
Community notes
Owners pair this with spark plug replacement because the symptoms overlap; worn plugs also cause idle flutter. If a throttle body clean does not cure it, ask for the plugs and the air filter to be checked next, both cheap. Many makers never admit a service exists for it, yet throttle cleaning is one of the most quoted jobs for the Myvi Gen 3.