Puff of grey smoke when starting - Volvo 850

Hi,

Whenever I start my '97 Volvo 850, whether it's been resting overnight
or just a few minutes, it blows out a puff of grey smoke, but after
that, there is no smoke from the exhaust during normal driving.

The car had gone about 10,000 kms before I realised it was consuming
oil, so was close to empty when it came in for a regular service.

Is the smoke caused by me running the oil dry? Is it likely to
continue?

Regards,

Han.

 

Light grey smoke is just water vapor, and is normal and
completely harmless. If the smoke is slightly blue-tinged,
it's probably just a little oil leaking down the valve guides
when the car sits overnight. That isn't terrible either, but
does indicate wearing valve guides or seals. It's a rare car
that doesn't produce a little water vapor from the exhaust on
startup. If you actually ran it out of oil, there will be
problems eventually, even if just shorter engine life.
--







http://freevision.org/michael/index.html

 

Were you using junk oil or quality oil ?Junk cheap oil will gum up your
motor so use a synthetic oil like mobil one .If you still blow smoke and use
oil its trouble .How long since you gave the car a good hot rev out and run
, Volvos love a clean out from time to time .

 

I have no idea where one would buy junk cheap oil in the USA. All of
the oil I have seen forsale meets the SAE standards for modern cars.
One way to have junk oil is to go beyond the suggested oil change
interval.

I have owned 10 Volvos and driven them over 1,250,000 miles total and
only use the oil that the Volvo manual recommends. It never recommended
synthetic oil, just real oil. I have had very few problems and none
engine related. When I started loosing a little oil in a '93 Volvo 850,
it was because of a bad seal which the dealer fixed. An 850 should not
use much oil at all. Always change oil and filter at the prescribed
intervals and always check the oil level when getting gas.

 

There have been several service bulletins since 1993 as well as entries
in the owner's manual that state,"The use of synthetic oil is highly
recommended." Due to its better detergent qualities over mineral oil ot
tends to keep the lifter orfices clear under extended (5000 mile or
more) oil change intervals. A further benefit is that synthetic oil
oxidizes less in high heat conditions which results in better lubricity
and less internal heat build up from friction. This is particularly
beneficial to the various lip seals in the motor.

In the OP's inquiry, the appearance of a puff of smoke on start up is
usually due to worn valve stem seals. The reason the smoke doesn't
persist is that the catalytic converter is scrubbing the exhaust so that
the small amount of oil that is bypassing the seals is being burned
cleanly. This in turn reveals where the oil is going. Since the oil
volume is being reduced it tends to operate at a higher temperature and
contributes less to both its cooling and lubrication function. Once the
consumption increases to a quart in between 500 and 1000 miles then
there is a wear issue than should be addressed. Consumption of a quart
or less in a 1000 miles is considered normal.

Bob

 

I'm using cheap 15/40 oil which was recommended by my mechanic. They
advised not to waste money on synthetic as it would consume that oil
quicker due to loose valve guides or seals. I took the car on a 4000
km roundtrip about 2 weeks ago.

Han.

 

"Once the consumption increases to a quart in between 500 and 1000
miles then
there is a wear issue than should be addressed. Consumption of a quart
or less in a 1000 miles is considered normal. "

By my calculations, I'm consuming about a quart every 600 miles. You
mention that the wear issue should be addressed, what can be done about
it apart from replacing the engine?

The '97 850 only has 124,000 kms. If you were to make a guess, how
close is the engine to giving up the ghost?

Regards,

Han.

 

Have someone competent look at the car and verify the source of
consumption. I suspect it's a valve seal problem since that's fairly
common. The engine is a sound piece and well built. Without serious
abuse the motor should last well into the 200K mile range. But then it's
so hard to see it from here.

Bob

 

Check the state of the PCV (Positive Crankcase Ventilation) system.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

WHAT ABOUT A GOOD WARM UP AND REV OUT FIRST .You will be amazed at the
difference just lower a gear so you dont have to speed .