قاعدة المحرك النشطة معيبة

A switchable engine mount that has stopped switching — stuck soft, stuck stiff, or leaking the vacuum or losing the solenoid that worked it. The consequence is always comfort, never reliability: shudder as the engine stops and starts, coarse idle vibration, a thump under hard acceleration.

On vacuum-operated designs, check the line before the mount. A split, perished or slipped vacuum hose produces exactly the same complaint and the same codes for pennies — and engine bay work is the classic disturber. The mount itself does wear out (its internal diaphragm or solenoid failing), but it is the second suspect, priced accordingly.