Fault code P0016: camshaft and crankshaft out of sync

The code sounds worse than it is in half the cases. But it must be checked before you drive on.

P0016 says the unit compared the crankshaft and camshaft sensor signals and found they do not line up. In plain words, the timing is out.

The causes fall into two very different groups, and everything depends on which one you are in.

Group one: oil and the cam phaser

On modern engines the camshaft angle is varied on the move, and oil pressure does the varying. Hence the most common and the cheapest causes:

1. Low or old oil. Thickened oil will not pass through the phaser valve, and the angle is never reached.
2. A blocked screen or the variable valve timing solenoid. Cleaned or replaced; the part is not expensive.
3. The camshaft sensor or its wiring. Same code, but the signal is to blame, not the mechanics.

That is half the cases and more — especially if the code appeared after a long overdue oil change.

Group two: mechanics

1. A stretched timing chain or worn tensioner shoes.
2. A belt that jumped a tooth, usually after a careless replacement.

Here you must not drive. On engines where the valves meet the pistons, the next start can cost you a cylinder head.

Telling one from the other

• Listen from cold. A rattle or rustle from the chain in the first seconds after starting argues for the mechanical group.
• Check the level and the age of the oil. If it is black and low, start there.
• See whether the code is steady. Appearing only from cold and going away once warm usually means oil and the phaser. Present always is worse.
• Do not keep cranking «just to see». If a chain or belt is suspected, every attempt is a risk.

After the repair

Clear the code and confirm it does not return over several trips, including a cold start: timing trouble shows itself from cold first.