Engine mounting the source of vibration

Q1: Whenever I stop at the traffic lights with the gear in Drive mode, the steering wheel of my automatic Proton Wira will vibrate although the engine is in a correct state of tune. What is causing this vibration?

Ho Jin
Kuala Terengganu

The cause is likely the engine mounting.

The mounting absorbs vibration generated by the engine during operation. As the rubber/insulator mounting wears off, it cannot absorb the vibration and therefore relays vibrations to the steering wheel.

It's probably tme for you to change the engine mounting.


Q2: I am driving a Nissan Grand Livina 1.6 with a manual gearbox. This MPV was bought new in 2009 and has covered only 14,000km to date.

The vehicle has been sparingly used and always driven sensibly with light loading. Sometime ago, I noticed a whinning noise from the gearbox. This noise is most obstrusive and annoying when the vehicle is driven on 5th gear between 60kph and 70kph. Each time I gently accelerate, the noise is clearly audible but when I release the accelerator, the noise disappears.

Beyond 70kph, there is no such effect whatsoever. What is the cause of this noise and how can it be eliminated? I have driven many manual cars before and they do not exhibit this noise except for some cars of yore (1970s & early 1980s models). This noise spoils an otherwise whisper quiet interior.

W.T. Ong
Petaling Jaya

Proper diagnosing must be done to identify the real cause of driveline noise that includes the clutch and its mechanism, transmission, lubrication property, bearing and free-plays, drive shafts and bearings.

Sometimes, the noise from the gearbox is caused by engine drive belts, and bearings such as those in the alternator, air-cond compressor, water pump and power steering pump.

Look into these areas first before concluding that the gearbox is faulty.

Is the car well maintained? Do you change the oil regularly? If no, then it’s better to change the transmission oil as recommended by the manufacturer and don’t forget to check the condition of the oil. Also, check for any metallic particles and find out if there is any burnt smell in transmission oil. 

The Nissan service centre should be able to locate the source of the noise and fix it.


Q3: My friends tell me that brake fluids must be changed like engine oil. Is this true and what are the recommended intervals?

Missy Hua
Penang

Yes, your friends are right. Ideally, the brake fluid should be changed every 40,000km or a year, whichever comes first. Brake fluid is hygroscopic, which means it can absorb moisture, and compromise its properties over time.

Normally, brake fluid absorbs moisture that lowers its boiling point for safer braking. Change the brake fluid as per manufacturer's recommended interval. Check your owner’s manual for more details.