Smoking 280SL

[rmadison]

1971 280SL 77,000 miles on engine, manual transmission. Makes lots of medium grey smoke in Stop and Go traffic on a hot day. Smoke stops after a minute of normal driving. May see a drop or two of oil at the end of the exhaust pipe after a smoking session.

No smoke otherwise except on first start up of the day when it makes a little gentle smoke for a minute or two. Car does not seem to burn an excessive amount of oil.

Are leakdown and compression tests in order? Can you suggest possible causes from these symptoms? valves? valve guides? rings? or what? Will spark plug condition tell me anything?

If it's rings or valves, about how much for a non-MB mechanic to repair?

Thanks,
Richard M

[Aaron]

Richard,

A rather common problem with these old straight sixes. Usually valve guides, seals or oil leaking past the base of the lifters. How many miles on the engine? I'd say to run a compression/leakdown test and see what results that brings first before tearing into the rest of the engine.

[ctaylor738]

Concur with what Aaron advised.

I would only add that you need to think about your long term plans for the car. You are about to start down the slippery slope with lots of "You really shoulds ..." where each "should" is major bucks.

One option is probably going to be a rebuilt head. You will then encounter choices about a new chain, tensioner, water pump, cam followers and assorted gear, slide rails, etc. The parts and labor will escalate to the point where a rebuilt long block may look attractive as a value proposition but only if you want to keep the car and drive it a fair amount.

Good luck and keep us posted.

[gmask]

Originally posted by ctaylor738
One option is probably going to be a rebuilt head. You will then encounter choices about a new chain, tensioner, water pump, cam followers and assorted gear, slide rails, etc. The parts and labor will escalate to the point where a rebuilt long block may look attractive as a value proposition but only if you want to keep the car and drive it a fair amount.

That'll easily cost between $2K to $3.5K :-(