I own a 88 240 sedan, 200k miles? (OD does not work)...engine does not smoke, no blow by in the oil...oil level remains stable...However, the tailpipe is black, and the engine shakes at idle (possible engine mounts?)...recent replacement of flame trap, never a problem starting...Any diagnosis please...Thank You, RWilliams...NewGuy

 

Hi RWilliams,

I once lived in St. Joseph and still have a host family there.

I'm not privy to 240, but it seems like A/F mixture problem, the fuel control is dumping more fuel than is needed or the engine may just need a good tune-up if not done for a while.

Here's a smoke chart:

Blue: Engine oil.
Dark grey/Black: A/F mixture too rich, or fuel/emissions control problem. If the engine is diesel, this is normal.
White: Normal water vapour or coolant seepage into the combustion chamber.
Green: Too bad[8D].

If the engine shakes, it may be trying to keep the correct idle speed, if it's too low. Or, it may be the engine mounts, as rubber parts wear out in about 5 years or so.

Post this question in the 240 section. People there have much better knowledge on 240 than I do and can help you better.

Good luck,


JPN