Smells in a Car

Preamble
Now that we have had a look at how to keep our cars trouble free. Well, here’s some more - keeping in mind that cars are somewhat like other living beings and let off distress signals when all is not well with them. So as an intelligent owner/driver, it’s worthwhile to detect them in good time before it’s too late - be it as a driver or as a passenger.

1. Fuel Odours:
Such smells can be most dangerous of them all - implying a potential fire hazard. These arise due to either a perceptible leak or ’sweating’ in the ‘plumbing’ between the fuel tank and the engine. A competent Garage or a DIY owner can spot them by inspecting the fuel lines to and from engine to fuel tank and take remedial measures.

However, in some of the present day cars, in-cabin fuel odours are often noticed even when the above plumbing shows no flaws. These have been traced to a faulty gasket on the fuel tank flange for accessing the fuel pump/level gauge under the rear seat! In the older non-Mpfi cars, in addition, these could also arise due to ‘over-filling’ the fuel tank.

2. Burning Odours:
Present day cars deploy a variety of synthetics and plastics within and outside their cabins. A ‘normal’ person can distinguish amongst these as those arising out of - a) Friction materials used on Brake Linings/Clutch Plates, b) Rubber or Plastic Parts and c) Lube Oils or other engine fluids.

The friction material odours can arise due to ’sticky’ brakes or more commonly, the Parking Brake not having been released fully. A Clutch too can give out burning smells if ‘rode on’ in heavy (b2b) traffic or uphill.

For rubber type odours, under inflated tyres are the most common culprits and plastic types prima-facie mean overheated electrical wiring either within or outside the cabin. Most common cause for such ones is the deployment of ‘unauthorised’ and crudely installed electrical accessories such as a high-powered Music System or a Remote/Central Locking System.

In addition, if the roof lamp is left on for long times, its plastic cover can over heat and emit such odours. Tampering with OE wiring harness is an absolute taboo with the present Mpfi Cars.

On the other hand, Oil/other fluids’ burning type odours invariably imply either an overheated engine or oil leaks from the engine/gear box coming into contact with exhaust line that can run as hot as 500.C+ next to the engine - tapering off to nearly 100.C towards the tail end. This too can be a fire hazard. Brake Fluid leaks within the wheel assemblies can also emit burning smells, as brake discs/drums can get very hot under hard braking.

3. In-cabin Odours:
The last of in-cabin odours can be ‘organic’ type - let off by decaying matter within. Most common ones are from the Car AC, due to rotting matter deposited on its Cooling Coil. Since such matter can gain access via the fresh air duct if kept open and in our conditions, it’s advisable to keep it shut most times. The only remedy here is to have the AC/Cooling Coil Serviced, which can be a time consuming and expensive. As in most cases, prevention is better than cure.

Other major offenders in this class are debris of eatables accumulating in the inaccessible corners. The best thing to do is to avoid any eatables inside the car especially with children and if inevitable, have the car internals first vacuumed thoroughly and only then have the various nooks and corners blasted out with compressed air - only to be vacuumed again. If ‘pre-vacuum’ were omitted, most of the dust so dislodged would settle down on the AC Cooling Coil - with its own undesirable consequences.

Having ensured all these, it’s a good idea to keep a car ‘air freshener’ inside but mind you, let it not be like spraying perfume to suppress bad body odours!

Also read:
How do I keep my car trouble-free
Noises in a car