Worse with A/C on or headlights/e-fan loading the alternator?

Careful visual inspection of vacuum lines (engine off, cool enough to be safe).

After a battery disconnect or ECU reset—did behavior change?

Scan for P0171/P0172, P0101, P0401 families depending on vehicle.

Check engine light on? Any fuel trim codes?

Avoid aggressive throttle-body cleaning as a default ‘fix’—wrong chemicals/procedure can damage components.

Recent intake work, filter change, or cleaning?

Use the guided flow to capture load and idle behavior together.

Does it smooth out as soon as you touch the throttle slightly?

Teşhis akışında belirti ve koşulları birlikte değerlendirin; genel liste her araca uymayabilir.

Belirti rehberi

Rough Idle & RPM Hunting: Intake, Fuel, and Sensor Clues

A rough idle or RPM ‘hunting’ is often felt as shaking at a stoplight or an idle speed that wanders. Small intake leaks, idle-air control behavior, MAF/MAP drift, and EGR flow quirks are frequent discussion points. A/C load and electrical load can change the pattern—useful for context.

Olası nedenler

Aşağıdaki başlıklar genelde bu belirtiyle birlikte anılır; motor tipi ve kilometre profili öncelikleri değiştirir.

Yüksek olasılık (genel örüntü)
Vacuum/intake leaks: small hose cracks and gasket seepage are common in rough-idle threads.
Orta olasılık
MAF/MAP measurement errors disturbing fuel trims.
Orta olasılık
EGR flow too high/low for the operating point.
Düşük — bağlama bağlı
Diesel fuel delivery unevenness at low rpm (injector/cleanliness themes).

Ayırt edici sorular

Bu sorular teşhis akışında da kullanılır; yanıtları düşünerek daha net bağlam oluşturabilirsiniz.

•Worse with A/C on or headlights/e-fan loading the alternator?
•After a battery disconnect or ECU reset—did behavior change?
•Check engine light on? Any fuel trim codes?
•Recent intake work, filter change, or cleaning?
•Does it smooth out as soon as you touch the throttle slightly?

İlk kontrol checklist

Careful visual inspection of vacuum lines (engine off, cool enough to be safe).
Scan for P0171/P0172, P0101, P0401 families depending on vehicle.
Avoid aggressive throttle-body cleaning as a default ‘fix’—wrong chemicals/procedure can damage components.
Use the guided flow to capture load and idle behavior together.

İlgili parçalar

Parça sayfaları bağlam sağlar; tek parça değişimi her zaman çözüm olmayabilir.

EGR valve MAF sensor MAP sensor

Tüm parçalar

İlgili arıza kodları

Kodlar yön verebilir; model ve donanım setine göre farklı kombinasyonlar görülebilir.

Tüm arıza kodları

Risk ve sürüş durumu

Sürüş: genellikle düşük aciliyet

Many rough-idle cases are annoying but not immediately dangerous—unless stalling happens in traffic or warnings appear.

Bu belirti ile teşhis akışına gir

Belirtiyi seçtikten sonra sıcaklık, yük, duman ve uyarı ışığı gibi koşulları eklemek genellikle daha isabetli öncelik üretir; tek başına metin yeterli olmayabilir.

Teşhise başla Tüm belirtiler

Rehber

Rough Idle & RPM Hunting: Intake, Fuel, and Sensor Clues hakkında (SEO)

Searchers often say “rough idle”, “RPM jumping”, or “car shakes in drive at stop”. Those phrases overlap heavily with intake and fuel trim discussions online—quality varies.

This guide favors calm prioritization: evidence (codes, trims), then testing—not parts roulette.