Q1: My 2011 Proton Inspira 1.8E A/T has clocked 63,000km so far. Even when it was new, the engine emitted a constant ticking or tapping noise when accelerating from standstill or when moving slowly uphill.



This only happens if the engine is kept under load, i.e. accelerating or going up hill and running at around 1,500rpm. Any faster or slower the noise goes away.



Initially I was worried that it may be from the CVT transmission and I have complained about the issue to many Proton service centres during every scheduled service but have been told that it may be engine knocking.



They have flashed the ECU but to no avail. They have asked me to try using RON97 petrol but there does not seem to be any difference when I do.



SH Lim

Petaling Jaya



If the car is still under warranty, you can bring it back to the dealership where it was bought. Any repair from external workshops must not be done at this time or else it will only void your warranty.



If you have heard this sound since it was new, it may be normal and is nothing to worry about.



To confirm, you need to compare it with another car of the same model. If the other doesn’t have that noise then you have enough reason to claim for warranty. Either they will replace your engine or replace your transmission if this is where the problem lies.





Q2: I own a 16-year-old Mitsubishi Pajero. The steering wheel vibrates when I am driving at around 80kph. But at  around 120kph, the vibration will sometimes go away.



When slowing down again, it will start to vibrate. The vibration can be quite violent, making the front portion shake. The vibration dissappears when the car is below 80kph.



My regular mechanic has done tyre balancing (with new tyres) and alignment of wheels. My engine mountings are also in order.



What else could be the problem? Is there any way of checking the steering wheel components?



Tom Ka’ang

Miri



Based on experience, there are three possible causes for this problem:



>Tyres are not balanced- even new tyres, still need balancing.



> Uneven tyre wear - this one is already eliminated as you already replaced with new tyres.



> Uneven rotor disc wear or uneven rotor disc expansion when it becomes hot- (this is felt only when you apply brake at high speed if hot judder and even at low speed if cold judder).



Have you replaced your rotor disc recently?



Hot judder occurs when the vibration is felt as you brake at high speed when the rotor disc is already hot and expanded. The cause is uneven expansion of rotor disc so this is material failure. The solution is to replace the rotor disc.



Cold judder happens when braking even at low speed. The cause is uneven rotor disc wear. The solution is to re-face/skim rotor disc.



If all of the above were already checked and are normal, you need to check your tie rods, your wheel bearings and wheel hubs and your suspension elements such as shock absorbers.



Other components that are associated with alignment and balancing such as linkages, lower arms or upper arms should be checked as well.



If the car had met with an accident before, you need to send it for body repair work to have the body and chassis properly aligned.





Q3: My 13-year-old Nissan Sentra has been running sweetly until lately. I have always kept it in tip top condition and it has repaid me with reliable running.



Recently, the steering rack seems to give a grating sound when turned anti-clockwise. It happens only once a while when I’m turning the steering wheel too often such as when backing into a tight parking spot.



If the rack is faulty, can it be serviced or must it be replaced. Is it expensive to replace?



Ning

Kuala Kedah



One of two scenarios are taking place here.



For power steering using fluid:



> Repair or replace only steering rack if there is oil leaks which leads to scratching some part of the rod because of lack of lubrication but if no oil leaks, you need to check your steering pump if it has enough steering oil. If there is enough steering oil, you need to replace it with new oil first if it was not replaced two years ago.



> Check if the power steering pump has oil leaks. If it has, then overhauling is recommended.



> Check also the pressure hose or feed hose for any oil leak. If there is, replace that component.



> Also check if the pressure hose is still the original one because replacement pressure hose are often the cause of noise in the steering system



For power steering using electric motor:



> Make sure that the noise is coming from the steering rack assembly with motor.



>  If the noise is coming there, you can try to lubricate the part of the steering rack which is connected or driven by the electric motor or just replace the whole assembly if lubrication is not possible with that type of power steering.

 

Sometime the noise is from the motor only and poor lubrication is the cause. And it can be replaced separately for some type of electronic power steering.



Make sure that the grating sound is not coming from the tyre during maneuvering otherwise it is normal.