New convert to the diesel Mercedes fold. I'm the proud new owner of a
1982 300CD-T, and I understand that some smoke is just part of owning
these cars. I get some white smoke on startup, but none that I notice
otherwise. I run B100 in the car. How do I know if the smoke is normal
Don't know about the B100 fuel. White smoke, usually lots of it is a
symptom of head gasket failure. Suggest you watch coolant level and if
coolant is in the engine oil and / or oil in the coolant. If neither and
no coolant loss is observed switch the diesel #2 to determine if the
B100 is the cause.
The white smoke immediately after startup of which you speak is simply fuel
that has accumulated during startup. It should disappear almost immediately
but on cold days may hang around for a bit. Also, the new glow plug relays
which stay on longer than usual will help eliminate white smoke that occurs
until the engine warms up.
However, if you have a continuous stream of white smoke you've got
oil-in-the-cylinder problems caused by bad rings, valve guides, etc., etc.,
Again, if the smoke goes away rather quickly don't worry unless you're
losing engine oil, coolant, transmission oil, etc.
The smoke goes away fairly quickly upon acceleration, and seems to be
most prolific when the car has been sitting for a while. I imagine that
Ernesto is probably right about it being unignited fuel. Although,
since it's heavier the longer the car sits, could it be moisture
accumulating in the fuel from the air?
Dude, you're burning coolant. You might get a little transparent
water vapour coming out your exhaust at the very very beginning
but white smoke especially that's heavier after the car site
longer sure sounds like a breached head gasket to me.
Keep an eye on your coolant level. My guess is it's dropping
ever so slowly. And shuoldn't be.
Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
just give white smoke (actually vapor I think). We used to get this
condition on the Contintental AVDS 1790-2A (air cooled, dual
turbocharged V-12) engines in M60A1 tanks when one or more jugs
(cylinders) would go bad. They would have insufficient compression to
ignite the fuel mixture in that cylinder and would come out the exhaust
as a white plume. The vapor would also make your eyes water and your
White smoke on start-up is usually condensation from exhaust gas.
Burning fuel results mainly in CO2 and water. As long as the exhaust
pipe is not warmed up the water damp is cooled and can condensate,
especially in cold weather. This is normal, cars with long exhaust with
relatively large diameter like mercedes will show this more than some
This is not a sign of a failing head gasket.
symptoms of water in the engine because of head gasket failure are:
Difficult first turn of engine after sitting overnight and lots of smoke
if the engine is warm. Small leaks may only result in slowly dropping of
Other symptoms are oil in coolant and coolant in oil
It's interesting how many different opinions there are of this. For the
record, the smoke simply smells like biodiesel exhaust, sort of like
french fries, and goes away almost immediately after I accelerate out
of my parking spot.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.