In a recent eBay listing I found a very well prepared descripotion of the rod bender issue:
"The Engine
When Mercedes re-designed the engine in the model year previous to mine, it started out as a 300SD (3 liter) Diesel engine. -- In an effort to upgrade the engine to a 3.5 liter,(350SD) they didn't strengthen the piston rods and increased the displacement (leaving less room between cylinders) With the heavier forces in the newly 'bored-out' and larger cylinders - the piston rods failed. Usually in the #1 cylinder first. These failed rods caused piston failure which in turn caused the cylinder to go 'out-of-round'. Oil goes up past the rings, unburned fuel goes down past the rings. Oil consumption increases, engine oil becomes diluted with diesel, further exacerbating the entire process.
Sure enough, right around 80,000 my tech suggested an oil consumption test and found that we had one of the faulty engines. Thank God for that Tech and the integrity of Mercedes - - they put a whole new engine in --at NO charge!! I have been humming along ever since - for about 145,000 miles now! These new and improved engines have gone for 500,000 miles. ---I think this car is one of them. Thanks again---Good luck!"
Please note that I have no interest in the car listed, just the fact that the seller's understanding and description of the real problem. The car has a supposedly new engine. It might make a nice car for someone. Not me though, I like the 124 chassis with the 603 diesel turbo. the 140 has way too much stuff to go wrong
DDH
Ebay listing is here:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4637892880
After the sale is completed and the link is dead I'll try to remember to remove the link but the words should be left for others to read, don't you agree?