Chassis may be misaligned

Q1: I'm driving a 2002 1.5 Proton Wira Aeroback. I have recently noticed that my car "jumps" around on uneven roads. When going on highways, the car sways at times.

I've just changed my front absorbers but noted that these problems happened before I changed them.
 
The wheel alignment is not 100% straight, even after the tyre shop has "corrected" it. Two shops told me that my tyres are "not good", and that they will undergo uneven wear.
 
I don't feel safe driving my car now. I'm in sales and I've to be on the road everyday.
 
Worried Wheels
Penang

The wandering steering and the bumpy suspension can be caused by defective front wheel alignment. Have it checked using electronic wheel alignment and adjusted according to manual specifications.

If the trouble persists, check chassis or body alignment. The chassis may be misaligned resulting in the front wheel misalignment as well.

Seek out an expert wheel alignment shop that can alter front wheel alignment specifications to resolve the problem.



Q2: My 2004 Toyota Vios has been emitting a cracking sound in the past few months when the engine is cool. The sound disappears if I turn off the air-conditioner, but increases when accelerating (either forward or reverse). It peaks if I shift to Neutral.

The sound slowly disappears after the car is driven for a while. I have changed both steering and alternator belts as suggested but the sound persisted.

The Toyota dealership claimed I have a faulty air-cond compressor, but it was just replaced less than 18 months ago.

Furthermore, the air-cond is doing its job in keeping the cabin cool.

EH Tee
Seri Kembangan, Selangor

An air-cond compressor can be spoiled at any stage of its lifespan.

Inspect the compressor performance. Do this by removing the drive belt and check the alternator, idler pulleys, water pump and air-cond compressor, then run the  engine.

If the cracking sound is gone but is replaced by sound from the air-cond compressor, the compressor is at fault.

Replace it and all will be well again.


Q3: We are normally advised to change engine oil after every 5,000km. Is it necessary if i'm using a semi/fully synthetic engine oil? Please don't ask me to refer to owner's service manual as your standard reply.

I want to hear from you guys, with your experience, a confident answer that all semi-syn can last x km and full synthetic can last y km.

From what I have been hearing from the oil blenders and those selling the oils, semi syn can typically be used for 8,000km, full syn for up to 15,000km to 20,000km.

Of course, you have to change the oil filters at 5,000km interval but the advantage is you can still keep on using the oils for longer intervals than mineral oil.

Walter
Sibu

We are sorry to have to give you the standard reply but again the most accurate and scientific reference in oil change is as per the manual instruction.

Yes, some oil blenders will promote their products as being able to last for a longer interval as they have tested and experimented with them.

So if you believe what they say about their products, you can follow the oil blender's instructions and specifications.

Bear in mind that proper car maintenance must always follow its manufacturer’s recommendations. Prevention of a problem is far better than an attempt to correct a problem after it happens.