Help Diagnose Problem- White Smoke.

[Guest]

Here is the scenario: 1956 Mercedes 300B (gas). Has started to smoke white heavily when started cold, but goes away when operating temp is reached. It did not do this when I bought the car 3 months ago. I realize that white smoke means coolant in the combustion chamber. Any thoughts, ideas whats going on here and how to put a "bandaid" on the problem? I enjoy driving this car around town, but I'm not ready to rebuild the engine yet! A friend of mine recommended to use radiator stop leak to plug the failed area. Thanks in advance! BTW "The Auction" 2002 at Imperial Palace was ok, nothing spectacular.

[Guest]

Try a new head gasket and while the head is off look for cracks around the exhaust valve seats.<P>I know removing the head on that car is a daunting task but how else will you get peace of mind?

[Guest De Soto Frank]

If it is brake fluid, it should give off a fairly acrid smell in the exhaust.<P>Coolant in the exhaust would have a hint of "sweetness" due to the presence of ethylene glycol.

[fordee9r (Ron Springstead)]

Bright white smoke is also caused by burning ATF... like through a bad modulator. Is the car auto or standard?

[Guest]

Try spinning the engine over and listen in the radiator. If you hear bubbles,check head gasket AND head.

[Guest]

Generally ATF{vacuum modulator only which I don't think Mercedes used} and brake fluid would be a constant while he says it disappears when warm, perhaps indicating it ceases with expansion of the metal.<BR>Early power brake units on Mercedes cars were I believe Borg-Warner remotes anyway

[randjflo60]

I don't have any new ideas but I do suggest to NOT use stop-leak!! Stop-leak can stop up places that aren't supposed to be stopped up.<P>We used stop-leak on a small 4 cyl. diesel generator at work one time as a temporary measure until we could replace the radiator. Then we had to replace the head gasket because it was plugged up with stop-leak.

[Guest]

White smoke, not to be confused with steam, is also caused by burning brake fluid. Check the vacuum line from intake manifold to the power brake booster, fluid inside says the booster diaphram is cracked.

[Guest De Soto Frank]

Chromejunkie,<P>To "slingshot" off of the preceeding post, I acquired a '63 Benz 220 Se sedan last summer with thoughts on fixing it up as a driver, only to learn how 'spensive old Benzs are to get parts for...<BR>you might want to stay away from the stop leak...the better part of valor may be to aggressively search for the cause rather than risk clogging the cooling system and "toasting" that expensive aluminum engine.<P>Also, check the oil for presence of coolant: foamy or milky looking oil on the dipstick.<BR>Coolant in the oil will wipe out every bearing if let go; previous owner of my 1960 Chrysler did this to the 383: coolant leak from headgasket into oil gallery; kept on driving it and adding water as necessary, until the engine started to knock real bad!<P>In addition to the suggestions already mentioned, I'd recommend a cooling system pressure-check or and/or a cylinder leak-down test, if the brake booster or tranny modulator are not the source.<P>A local AMC Dealer has a mid-'50s M-B 300 in his showroom; very nice car- I hope your problem is minor in nature and easy to rectify!<BR>As for my '63, gotta figure out how much "cabbage" I wanna sink into a "green four-door sedan" with a later 280 engine...just to have a "driver"...<P> <P>Best of luck to you!

[Dave@Moon]

A good dead-giveaway for a coolant leak into the combustion cylinder is to look for one or more spark plugs that are decidedly cleaner looking than the others. The coolant on ignition turns to steam and steam-cleans the combustion chamber, removing any built up carbon (i.e. "decoking" that cylinder). This could give you a clue where to check most closely for flaws when removing the head.