Ticking Noise from the Engine — Common Causes

What's happening

A ticking that follows engine RPM (gets faster as the engine revs) is usually mechanical — valvetrain, injectors, or pulleys. A tick that follows engine speed but only when cold often means a hydraulic lifter that is taking too long to pressure up — frequently due to dirty or low oil. A tick that follows RPM and is loudest near the exhaust manifold is almost always an exhaust leak (a 'ticking exhaust manifold' or cracked manifold).

You might also notice

• Loudest at idle, faster with RPM
• Sometimes goes away when warm (oil)
• Sometimes louder cold and stays (exhaust leak)
• Possibly a slight smell of exhaust under the hood

Likely causes (most common first)

1. Low or dirty engine oil
2. Worn or sticking hydraulic lifter
3. Cracked exhaust manifold or failed gasket (very common on Ford, GM trucks)
4. Loose spark plug
5. Direct injection injector tick (normal on many engines, but louder when failing)
6. Worn rocker arms or valvetrain

What to check first

1. Check the oil first — dirty/low oil causes lifter tick
2. Use a long screwdriver as a stethoscope: touch various spots and listen at the handle to localize
3. If the tick is by the manifold and you smell exhaust, it is almost certainly an exhaust leak

Common OBD2 codes for this symptom

Don't have the code yet? Look up your code or read it with AXLY.pro.

Can I keep driving?

Drivable while you diagnose. Get the oil changed and re-listen — that fixes a surprising number of ticks.

Confirm with the actual code

Symptom-based diagnosis narrows the field — reading the actual stored code finishes the job. AXLY.pro is a free iPhone app that pairs with any Bluetooth OBD2 adapter and reads every stored DTC.