| "What
Is That Smoke Coming From Your Tailpipe? What
Can You Do About It?"
Every car, except the rare electric vehicles,
has a tailpipe and gives off exhaust. However,
some cars just go too far.
You see them driving down the street every day
– cars with thick, smelly smoke billowing
from their tailpipes. Not only is it impossible
to see through and unpleasant to get stuck behind
on the road, you know that what you’re seeing
cannot be good for the air!
However, what do you do when your car is the
offender? It all depends on what manner of smoke
your car is sharing with the world.
During normal operation, the emissions from a
car's tailpipe should be invisible. But, what
if they're not? Should you be worried if you notice
what looks like smoke? What should you do?
Proper modern service shops employ diagnostic
machines capable of pinpointing the cause of bad
emissions in a matter of minutes. The cost is
typically around $50. Still, there are steps you
can take to monitor your car’s exhalation:
Thin white vapor: Don’t
worry.
A thin cloud of white vapor that quickly dissipates
after leaving the tailpipe is probably the result
of normal condensation buildup inside the exhaust
system. It should disappear after only a minute
or two of engine operation. It may even be accompanied
by a slow drip of water. This is a common sight
when cars, even new ones, are first started in
the morning, since condensation builds up overnight
like dew on the grass.
Blue or gray smoke: See
a mechanic.
Thick blue or gray smoke that doesn't dissipate
quickly is most likely the result of oil burned
in the engine's combustion chamber. It can be
caused by something as minor as clogged oil passages,
or it may point to something more serious that
could require extensive engine work –like
an oil leak caused by weak seals around the pistons.
If your engine is burning enough oil to produce
visible exhaust smoke, the oil level will drop
over time and require periodic top-offs. That
will cost you because motor oil isn’t free.
(Just ask the Saudis!) Worse still, burning oil
can foul the engine's spark plugs, causing breakdowns
ranging from rough idle and reduced fuel mileage
to hard starting and sluggish acceleration.
On turbocharged and fuel-injected vehicles, the
presence of bluish-gray exhaust smoke may indicate
turbocharger failure, especially if accompanied
by a high-pitched whine. The turbo may need to
be repaired or replaced. The oil lines to and
from the turbo should also be replaced. A properly
experienced mechanic will be able to take care
of both.
Regardless of the cause of this type of smoke,
you should have the vehicle checked out by a qualified
mechanic as soon as possible.
Black smoke: First, replace your air filter.
If it doesn’t clear, see your mechanic.
Black, sooty smoke is usually symptomatic of
an engine that's burning too much fuel and nearing
collapse. Because engines run inefficiently when
cold, they use extra fuel at start-up to ensure
a smooth idle and hesitation-free acceleration.
If the smoke clears up as the engine warms to
operating temperature, it's probably nothing worth
your worry.
Should the smoking persist, a clogged or dirty
air filter is a likely culprit. On carbureted
vehicles, the choke and choke linkage could also
have a buildup of gum and varnish. If the filter
checks out OK, a faulty sensor, a clogged fuel
injector or another intake-system component may
be the cause.
Because of the vast complexity of modern fuel-injected
engines, your best bet may be to have the car
checked out by a mechanic with specializes in
these types of repairs.
Thick white smoke: Call
a tow truck and head to your mechanic.
Unlike the wispy white vapor described above,
billowing white smoke is usually an indication
of serious engine trouble and warrants immediate
attention.
If you continue to drive the vehicle, the engine
could overheat and suffer extensive damage. Smoke
of this sort is usually caused by the engine burning
coolant, and can be the result of a blown head
gasket, a damaged cylinder head or a cracked engine
block. Such serious failures can mean a new engine
or an engine rebuild – or even a new car
entirely.
Even a small coolant leak can lower the engine's
fluid level, resulting in overheating and catastrophic
engine damage like a seize-up. A coolant leak
into the engine's oil system may not cause any
tailpipe smoke but could cause the oil to become
thin and milk. Finally, the coolant can turn to
brownish sludge – which is useless to your
engine. These conditions also require immediate
attention.
You shouldn’t panic when a little puff
comes from your tailpipe, but keep an eye on it.
Your vigilance and knowing what to do in these
worst-case scenarios could mean the difference
between a a minor adjustment and a major repair.
|
