I own an Impreza 2.5TS 2002

Motor is jerking at start up.

The problem is intermittent and become apparent when I start it in the morning after or during a rainy day. At the beginning I thought that the clutch was causing the problem because it jerks only at first gear friction point & usually disappears when engine gets warmer.

The dealer has replaced the clutch under warranty but the problem remains – it is getting worse since fall started.

Now the problem is showing even at motor idle and last until motor gets warmer.

Any advice?