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1990 Mercedes-Benz 560SEC Question: Engine Smoking



slfbm, Mesa, AZ, May 29, 2011, 01:38

Just bought the car. Had high idle and ABS light on. Found bad fuse for that and brought idle to normal. Runs good, oil pressure very good. After about 5 miles of driving it all of the sudden started smoking. Looks blue to me but could be lighter color. Any ideas why it didn't smoke before or what could have caused it to start smoking now or what to do to fix it? Drove the car several times prior to fixing idle and had no indications of smoking at all. Even now seems to run fine, gauges all look good, just smokes bad. Thanks for the help

2 Answers
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  • Answer #1

    May 31, 2011, 13:20

    Check first that the oil isn't overfilled. Sounds like the engine doesn't smoke until it's at running temperature. First, check the PCV system. If that's OK, I'd suspect that the piston rings are stuck from dirty oil or collapsed from overheating. If the oil's clean and not overfull, and sticking rings are suspect, you may be able to improve the situation by removing the sparkplugs with the engine warm and putting a teaspoon of Liquid Wrench penetrating oil into the cylinders and letting it sit overnight. Put the plugs back in and start it up and drive it. If it's stuck rings, that could fix it. Good Luck.
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  • Answer #2

    April 15, 2013, 02:18

    Check cam oiling system. Have had this problem on two 560s, both cases the cam oiling system needed replacement of plastic parts.

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  • Reply

    slfbm, April 15, 2013, 15:40

    Thank you for that information. I am not having much of a problem with it any longer.
    Had oil changed and put in correct oil and seems to have all but cured the problem.
    Still will give a little puff of smoke on take off after it has been running for
    several miles. Again thanks and I will keep your information in mind.

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