What are the signs of a dropped rocker?Updated 18 minutes ago

The most common signs are a sudden misfire, a check engine light, a new ticking or tapping noise from the cylinder head, and a loss of power. These can have other causes too, so only an inspection will confirm it.

Common signs

• A misfire or rough idle, often on one cylinder
• A check engine light, usually with a misfire code
• Ticking, tapping or clattering from the top of the engine
• Low power
• Oil leaking from the tappet (rocker) cover, or a smell of burning oil

On FA and FB engines, a loose rocker can be picked up by the camshaft and punched through the tappet cover. Oil can then spray onto the exhaust, which is a fire risk.

What to do

• Stop driving as soon as it's safe. A loose rocker can get caught in the valvetrain and turn a repairable problem into a rebuild.
• Don't rev the engine to see if the problem clears.
• Have the valvetrain checked by a qualified mechanic before you drive the car again. That means taking off the tappet cover and inspecting every rocker.

Reducing the risk

Rocker Retainers are designed to hold the rocker in place if valve spring pressure is lost for a split second, which reduces the risk of a dropped rocker. See What is a Rocker Retainer? and Which engines do you make parts for?