I've been asking questions about engine transplants and such, and it occurs to me that perhaps I should back up and fill in the details of my story....
I received two weeks ago the w123 240d that I got off eBay back in late June, from Texas. The car was listed as having a bad engine, seller said he had been told by the Mercedes dealer two cylinders were dead. Has approx. 140k miles, verified as accurate by Carfax. It's very, very clean inside and out except for the dash top... even by 'hot/dry state' standards. The engine was almost unbelievably clean, nearly pristine in fact. Now to back up further, the seller's story was that the original owner had a stroke and was unable to drive the car, and he bought it after it had sat for two years. During that time, the keys were lost. He said he bought the car on the family's word that it was a gem, then took the car to the dealer, they made a key and when they started it, bingo big problems. He took it to an independent garage, which confirmed the dealer's diagnosis: two dead cylinders. Plus the car would only go about 15 mph. When I got it, it would barely run, shook like mad at idle and at higher revs, and smoked like crazy, like a Navy exercise, both oil smoke and diesel smoke (unburned). I began to attack it in increments. 1. First, the low speed condition is simply due to a broken linkage bushing assembly, where the linkage exits the firewall. With it rigged in place, the car makes some speed. (Throttle linkages are good when they work.) 2. I put in half a tank of fresh diesel with ATF mixed in and it ran better, half the smoke. At this point I drove it and it pulled NICELY. So at this point I am thinking that if this thing has two dead pots, my god it's the fastest 2-cylinder diesel on planet earth. Things are not adding up. 3. I changed the fuel filters, and the (leaking like mad) primer pump, and poured Purge into the big filter when I put it on, and it ran much better and stopped smoking most of the time. But it still shook like mad. 4. So today a friend stopped by who has more diesel tools than I. Low and behold we start it and it's now shaking less than before, but still way too hard. So we cracked the injector lines. Loosening #1 an d #2 made no difference to the engine at idle at all. The other two performed as you would expect. 5. So we pulled the injectors out of #1 and #2 and did a compression test. - #1 ZERO, no movement at all on the dial when cranking - #2, shows strong movement right up to almost 500pds (yes, we checked this twice) 6. Now my pal and I differ on our take on this: he says he believes #1 probably has a hole thru the piston. While I admire his Kresgin-like ability to see through metal (LoL, have to or I would cry), I vote for a valve problem. As for #2, it appears to be an injector issue or possibly a delivery pressure issue (that is, pump). OKAY, so here I sit. I now have a choice: either roll the 240d parts car into the shop, swap out the engine with a known good one, then pull the existing engine apart at my leisure, OR we pull the head off this one while it is still in the car, and see what we have to pay the Piper. Thoughts, ideas, most appreciated. Mac Aylmer, Quebec '60 Mercedes 220s / '82 Mercedes 240d / more 240d parts cars on the way! '75 Volvo 164e / '88 Volvo 245 Maybe a '90 Jetta TD....
