What causes the abnormal noise at the moment of starting a 2009 Highlander?

[KeiraFitz]

Reasons for abnormal noise at the moment of starting a 2009 Highlander: Engine mount rubber aging or loosening: The engine mount rubber is the rubber block placed between the engine and the vehicle frame. Its function is to reduce the vibration and buffering during engine operation and to secure the engine. Once the engine mount rubber ages or loosens, the engine will shake, and in severe cases, a "clicking" abnormal noise may occur. Excessively rich air-fuel mixture: When the engine's air-fuel mixture is too rich, the symptoms include difficulty accelerating after starting, uneven engine operation; black smoke from the exhaust pipe, accompanied by a clicking noise from the engine, sometimes backfiring; reduced engine power and increased fuel consumption. "Piston slap" abnormal noise: Due to poor lubrication conditions, excessive wear of the piston and cylinder wall leads to the clearance fit tolerance between the piston and cylinder wall exceeding the normal range. When the engine is running, the piston skirt impacts the cylinder wall, producing a crisp "clicking" sound, which is usually more noticeable at idle or low-speed operation.

[LenaRose]

I also experienced a clicking noise when starting my 2009 Highlander, and later found out it was due to some wear on the starter motor gear, causing slippage and noise during cold starts. After all, this car has some years on it, and many older owners have reported similar issues, especially during cold weather starts. It could also be related to a loose or aged engine belt, as a slack belt can produce squeaking sounds when pulled during startup. I first checked the belt tension and adjusted it if necessary. Additionally, slight shifts in chassis components like suspension ball joints or shock absorbers might cause rattling noises during ignition. My advice is to start with the simple things—listen to where the noise is coming from. If it's minor, have a technician check it during regular maintenance. If it happens frequently, it's best to visit a professional shop to inspect the starter motor or belt system to prevent small issues from turning into bigger problems.

[DanielMarie]

As someone who has been repairing cars for over a decade, I've encountered numerous cases of abnormal noises during startup in the 09 Highlander. The most common issue lies with the starter—either the electromagnetic switch or the pinion gear gets stuck, resulting in a clicking sound when the gears don't engage properly during ignition. Another culprit could be the drive belt system; if the belt has aged and hardened or the tensioner pulley bearings are worn, you'll hear a squealing noise during cold starts as the belt pulls. Pay attention to the type of noise: short metallic clunks typically point to starter-related issues, while continuous friction sounds may indicate a loose belt or accessory components. I recommend first checking the belt for cracks or slack—a healthy belt should have enough elasticity and not depress more than half a centimeter. Diagnosing starter problems requires professional tools, so don't delay too long, or you risk burning out the motor, which would be far costlier to replace. In short, early detection and minor repairs can save you from being stranded on the road later.

[NevaehDella]

The 09 Highlander is an old-timer, so startup noises aren't uncommon. From my experience, older vehicles often develop belt system issues - like the power steering pump or AC compressor belts making noise during startup due to uneven tension. A weak battery can also strain the starter motor, causing unusual sounds. Worn suspension components like stabilizer bar bushings may rattle during cold starts with strong vibrations. Quick self-check: identify the noise location - front usually means motor/belt issues; undercarriage noises suggest bushing inspection. Regular belt replacement costs just a few hundred bucks, much cheaper than motor replacement. Don't ignore these warning signs in older vehicles - timely maintenance can extend its lifespan by years.