I have seen posts about rough idling issues with the 560 SEL and some issues with the suspension. I'm looking at a 1987 560 SEL, florida car with no rust and 143K miles, has a rough idle but other than that runs quite well. Is this a car I'm going to regret buying? Don't know if the timing chain has been replaced or not. Are the engines difficult to work on compared the the straight 6 gas or diesel models (I drive a 300D and a 240D).