Ventilation ducts may be culprit

Q1: I own a 2004 Proton Iswara Aeroback.  There are exhaust fumes entering the car cabin. 

I had the ventilation holes sealed up by air-cond technicians, replaced the window, door and boot rubber seals and changed the middle section and end section of the exhaust system as advised by an exhaust shop.

I have sent the car to several mechanics, air-cond shops and exhaust shops after the abovementioned work had been carried out but all of them were unable to locate the problem causing the exhaust fumes to enter the cabin.

What can be done to eliminate the exhaust fumes from entering the car interior?

Driven Crazy
Ipoh

Given that your mechanic has sealed all possible places where the exhaust fumes could gain entry, the only places left to look at are the air-conditioning recirculation or ventilation ducting. 

The ducts allow fresh air to enter the cabin. Have them checked.


Q2: I noticed that my brakes will emit squeaking sound randomly when I reverse the car or move forward at very low speed.

In a jam, the brakes emit loud noises when I let go the brakes after a complete stop.

My car's front disc brakes were changed about a month ago and the mechanics said the brake disc and pads are still in good condition.

Simon
Selangor

Common causes are warped brake disc;  incompatible brake pads used; dirt trapped between pads and discs;  worn or faulty brake components;  worn or improperly positioned noise indicator; or the back plate is touching the disc.

Once your mechanic has identified the cause, he should be able to deal with the problem and stop the noise for good.


Q3: I have a 1993 Nissan Bluebird with manual transmission.

A peculiar problem has surfaced whereby there's a 'stud' sound whenever I'm releasing the clutch on take-off or releasing the clutch quickly during upshifts.

It happens once in a  while.

Gearshifts remain smooth. What’s the matter?

Raymond
Kuala Lumpur

The probable causes are worn-out release bearing;  worn-out or faulty pressure plates or clutch disc; or a sticky clutch.

Send your car to a reputable workshop and ask them to check the clutch and gearbox.