What are the reasons for the ticking sound in the Haval H6 engine compartment?
4 Answers
Haval h6 engine compartment ticking sound reasons are: 1. The vehicle has been parked for too long, causing most of the engine oil to flow back to the oil pan, failing to form a protective oil film in time during cold start and resulting in metal impact sounds in the engine; 2. The fit clearance between the piston and cylinder wall is too large; 3. The oil pressure is too low, and the cylinder wall lubrication is poor. Take the 2021 Haval H6 third-generation 2.0T automatic two-wheel drive Max as an example: it is a compact SUV launched by Great Wall Motors, with a length, width, and height of 4653mm, 1886mm, and 1730mm respectively, a wheelbase of 2738mm, equipped with a 2.0T turbocharged engine, a maximum power of 155kw, a maximum torque of 325nm, matched with a 7-speed dual-clutch transmission.
My Haval H6 had the same issue before, where a ticking sound could be heard as soon as the hood was opened, especially noticeable during cold starts. Later, I found out it was mainly caused by insufficient oil or wear in the hydraulic valve lifters, which are responsible for adjusting valve clearance. When they age, unstable oil pressure leads to knocking sounds. Additionally, I checked the timing chain—a failing tensioner can cause the chain to loosen and slap against the guides, producing a metallic clanking noise. The electromagnetic valve action of the fuel injectors during operation can also create a rhythmic ticking sound, but this is normal. The most critical factor not to overlook is the engine oil. Incorrect viscosity or insufficient quantity can lead to poor internal lubrication, causing dry friction and unusual noises. I recommend first identifying the sound source: if it's near the top of the cylinder head, it's likely a valve issue; if it's around the timing chain area, focus on the tensioner. Also, ensure you use 5W-30 full synthetic oil. If the sound worsens after the engine warms up, visit a 4S shop immediately for a stethoscope diagnosis.
Having repaired cars for ten years, I've handled numerous cases of rattling noises in the Haval series. The most common issue is actually with the high-pressure fuel pump, which operates at 200Bar pressure. When the plunger wears out, each fuel injection produces a crisp rattling sound, and you can feel distinct vibrations by touching the pump body. Another possibility is a seized alternator one-way pulley. This pulley is supposed to rotate unidirectionally to cushion vibrations, but when it fails, the belt pulley will produce hard knocking sounds. For self-diagnosis, try removing the alternator belt - if the noise disappears, it's an accessory problem. Additionally, excessive clearance in the turbocharger's floating bearing or loose wastegate valve rods can create metallic knocking sounds during rapid acceleration. The most concealed case I encountered was cracked air conditioning compressor clutch plates, which produced a distinct 'da' sound with each rotation. These faults produce slightly different sound characteristics, which experienced technicians can distinguish using a stethoscope.
Just helped my neighbor troubleshoot the cold-start rattling noise issue on his 3rd-gen Haval H6. The tapping sound was particularly noticeable at idle, and its frequency increased when revving the engine in neutral. The key finding was the carbon canister purge valve causing the trouble—this black plastic valve mounted near the intake manifold clicks open/closed every 30 seconds to purge fuel vapors. Normally it produces a faint ticking, but when the valve sticks, it turns into continuous knocking. There's also injector noise—direct injection engines operate with high fuel pressure, so injectors naturally produce ticking sounds during operation, though carbon buildup in older cars may cause uneven needle valve movement and louder noises. For inspection, you can place a screwdriver against suspected components and listen through the handle for more precise diagnosis than direct listening. If all else fails, use a down-to-earth method: unplug each fuel injector connector one by one—when the abnormal noise disappears upon unplugging a specific one, that's your culprit.
