OBD-II code · Powertrain (generic)

P050D Cold Start Rough Idle

The ECU detects rough idle behaviour during the cold-start phase only. Once the engine has warmed up the issue disappears. Typically caused by injector deposits, low compression on one cylinder when cold, or sticky valve guides.

Is it safe to drive with P050D?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyInjector tip coked - poor cold spray pattern
  • PossibleValve guide sticky when cold

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.5–3 h
Emissions test
Likely to fail
Parts involved
Fuel Injectors, Cylinder Compression, Valve Guides

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.