white smoke out the tailpipe - 69 280 sl - PeachParts Mercedes-Benz Forum

tadink · #1 02-05-2009, 08:55 PM

our 280SL made a 'funny noise from the engine' and then my wife
noticed 'lots of white smoke' out the back of the car. groan.
Luckily she has learned from the first 'smoke' incident that 'smoke
is bad' and she pulled over quickly.

she indicates that the smoke was white to greenish white, no oil
color or smell to it. the radiator reservoir is empty, but no sign
of oil in there either. there is no water on the dipstick, nor any
signs of leaks around the engine block.

I am thinking that the issue is likely a head gasket, but am
wondering about my troubleshooting procedures.

My plan is to pull the plugs and examine, then compression test - by
hand cranking - each cylinder to see if there are any noticeable
issues. then what? is the head gasket on the 110 engine a big deal,
little deal, or something left to Dr. Mercedes at the classic car
hospital?

is there anything else that I should be looking for? I'm trying to
think of happy thoughts and little things it might be, but cannot
think of any other way that water gets out the tail pipe that does
not sound serious!!

thanks

tom

Engr693 · #2 02-05-2009, 11:08 PM

Can only be bad news and usually means one thing...coolant in the combustion chamber. Could be head gasket, cracked head, cracked block.

meltedpanda · #3 02-06-2009, 09:40 AM

agree with Gary - white smoke, no fluid in resivoir, none in oil, means it is being combusted.
Not good

tadink · #4 02-06-2009, 12:38 PM

thanks guys...that is certainly not the best news of the day, but I thank you for chiming in.

now, for the diagnostics and troubleshooting....am I on the right track with what to look for [see above] or is the diagnosis solid enough to start pulling the head and look inside to see what the damage is?

and, if I need to pull the head, is Haynes Manual good enough for a guide or should I try to come up with a shop manual?

maybe someone here has already described the procedure in some detail?

thanks all...

tom

meltedpanda · #5 02-06-2009, 02:54 PM

test compression and let us know what you find. You could also get a block test kit, some parts stores carry them, supposedly good for head gasket test. I have never used one but I hear they work well. Hanes manual is a start, but you will need more information than it provides. Of course if it is a block issue that is a diffrent story
Are all these systems functional and in good repair, something caused it? Radiator- Thermostat, Coolant leaks- Cooling fan-Water pump?
Ever overheat
your post indicates a "sudden onset" that is usually not normal for a head gasket

awhile back a poster listed these checks
There are several ways to check for a head gasket. Start the engine cold with the pressure cap off the pressurized surge tank. Watch the coolant in the surge tank for signs of bubbling or "false boilling". If so then it may be a sign that combustion pressure is entering the system through a failed head gasket.

Pump up the cooling sytem pressure with a cooling system pressure tester pump. Hold it at 15psi for several hours. Keep pumping it up if the pressure drops. Pull the plugs in the mean time. After several hours holding pressure rotate the engine with the starter with the plugs out. Watch for coolant spewing out the spark plug ports as a sign of a leaking head gasket.

With the cooling system full, apply 120psi shop air to each of the combustion chambers, one at a time, thru the spark plug port. Make an adapter out of an old spark plug shell and run shop air to the port. Rotate the engine so that the valves for that cylinder are closed. Watch the coolant in the surge tank for bubbling. If the chamber holds the 120psi with no bubbling then chances are the head gasket is fine.

Good luck