Engine rebuilding vers doing a quick fix

[Craig Dale]

I have a 1988 560sl, after a lengthy line up apx 2hr my engine started to smoke very bad . After a few miles it did clear upyho , the next day same thing when starting up and idling for a short time to make matters worse white smoje appeared. The engine never registers hot or overheats

[Sugar Bear]

Could be a bad diaphragm in the transmission modulator. Pull the hose off at the modulator and check for ATF in the line, that would account for white or very light blue smoke. Transmission shifting ok? Fluid up to the mark?

Losing any coolant? Send out an oil sample to a lab to check for coolant in the oil.

Valve seals are a common problem and cause smoke on start up or during very high vacuum situations. They are replaceable without removing the cylinder head.

Mark an upward pointing reference index on the spark plugs, remove them. If there is an ash deposit on the porcelain on the side of the plug pointing toward the the valves (particularly the intake valve) the valve seals are leaking.

A rebuild? IMO, not yet, need more diagnosis. Those engines are very robust on the bottom end. Unless it is very high mileage or has been overheated the problem is probably top end only.

How many miles? Been overheated? Clean inside?

Good luck!!!

[97 SL320]

Also remove the air filter lid and look for oil in the air filter ( from the crankcase breather. ) If you have oil up there check the PCV valve system for a clog.

What is the history of this car? Has anyone put additives in the fuel tank?