How to Recognise This Problem
- Rhythmic knocking or tapping that increases with engine speed
- Metallic rattling sound, especially when the engine is cold
- Knocking that gets louder under acceleration or load
- Ticking sound from the top of the engine (valve train)
- Deep thudding knock from the bottom of the engine (big-end bearings)
- Engine warning light illuminated
What Causes It
- Low engine oil level or degraded oil losing viscosity
- Worn main or big-end bearings
- Excessive carbon buildup causing pre-ignition (pinging)
- Worn hydraulic lifters or valve train components
- Loose or stretched timing chain
- Poor fuel quality causing detonation
- Piston slap from worn cylinder walls
What Happens If You Ignore It
Complete engine failure if bearings seize — requiring full rebuild or replacement
Connecting rod can break through the engine block (catastrophic)
Timing chain failure can cause pistons to hit valves (bent valves, damaged pistons)
Continued driving can turn a $200 repair into a $2,000+ rebuild
Loss of engine power on the road, creating a dangerous situation
Repair Solutions
Oil Service & Inspection
If caused by low or degraded oil, a fresh oil change and inspection can resolve simple cases. From $40.
Valve Train Repair
Worn lifters, rocker arms, or valve clearance adjustment to eliminate top-end ticking. From $100.
Timing Chain Replacement
A stretched or worn timing chain needs replacement before it fails completely. From $300.
Engine Bottom-End Repair
Worn bearings require dropping the sump or full engine removal for repair. From $500.
Don't Wait — Get It Diagnosed
The sooner you identify the problem, the cheaper the fix. Book a diagnostic at J&B Motors in Harare today.