Just a few random notes from tinkering with my new 1993 300D 2.5 Turbo (124.128). I'm learning all kinds of things from this one. Figure I better share before I forget all of it: 1) There is no power steering cooling circuit... the pump connects straight to the steering box. 2) The rear sway bar flexes like cooked spaghetti when you push it with your hands. It's a dinky 13mm unit. The EPC says this bar was only used on cars with SLS, and SLS was not available on USA diesels. It *should* have a 15mm bar, according to the EPC. Uh-oh, maybe the EPC isn't infallible, lol. 3) The 1993 ABS pump is different than the 1987 pump. And, the lines are totally different. So, I can't just install the 400E brake lines to match up with a 400E master cylinder & booster combo on my 1987 300D. Bummer! (It would likely work ok on the 1993, but I am not installing larger brakes on the 2.5T - just Porterfield pads & WRXtra stainless braided brake hoses.) 4) There is no overboost protection circuit on the 92/93 OM6002.962 - no sensor, no switchover valve, nada. The intake fitting plugs directly into the ALDA, with a "Y" to feed the computer's boost sensor. This is because of the reverse Polish wastegate, which is fully open (no boost) until the computer applies *vacuum* to close it. There's a separate boost pressure sensor that tells the computer how much boost is present. A wastegate swap will correct this. 5) There is no BFS (Blue Flying Saucer) circuit for the tranny vacuum signal. The output from the VCV goes straight to the tranny. The FSM indicates that the cold-shift characteristics are now controlled by the valve body, instead of an external signal. But how does it sense boost pressure, which was the purpose of the BFS? Overall, the tranny behaves much better than the 1987 722.3. At filter change time, it takes 6.0 quarts to re-fill (compared to 7.0 for my 1987 300D, and 8.0 for the 500E). 6) The ASD hydraulic reservoir makes headlight access very, very tight. I drained & re-filled with new fluid. The return hose was shot (brittle)... it's the type with an external cloth braid. The filter (strainer) was filthy - I replaced it along with the hose. The fluid turned dark right away again. I repeated the flush after a few thousand miles, and it still turned dark. I'll have to do the drain/refill drill a few times as a "flush" of the system. The hydraulic fluid isn't exactly cheap (over $10/liter aftermarket) but I figure it beats major hydraulic repairs. 7) My May-1993 build car still has the contact ring, instead of spiral, in the steering wheel. The C36 AMG steering wheel bolted in using the contact ring from the stock wheel. I really miss the telescoping wheel & memory seats. What a shame that wasn't standard. 8) The cruise amp wiring harness & connector has no wire or pin for terminal #14, which allows the "016-" cruise amp to work without pulling a wire out (you must pull the #14 wire when using the 016- amp on older W124's - there's a TSB in the WIS about this, the PDF is on my website.) 9) The wiper is a weird hybrid, same as my July-93 built E500. It has the old wiper transmission with non-replacable metal housing, with the new, long, 1-piece seal across the windshield. Later 94/95 models have a plastic cover that can be replaced so it looks pretty. Mine is painted black and if it's scratched, it has to be repainted. 10) The OVP relay is different. The old (1987) style is a single circuit, with one fuse. When the old style acts up, you lose the engine computer (EDS and ELR) as well as get an ABS warning light on the dash. The new (1990+?) style is dual circuit, with two fuses. It appears that the EDS/ELR and ABS have been separated, so failure on one won't affect the other. In my case, the EDS/ELR and tach were dead, but I had no ABS light. So, I thought the crank sensor was bad, and replaced it - no change. Then, I did what I should have done in the first place... tap on the OVP relay while the tach was dead. Bingo, the tach jumped to life and idle speed picked up. A new OVP relay cured the problem. Side note... on the 90-up 2.5's, when the tach/EDS is dead, there's no boost either... that's due to the vacuum-operated wastegate that defaults to open (zero boost) unless the computer signals a solenoid to trigger a vac source. So I had a dead tach, low idle speed, AND no boost! 11) The afterglow function uses a temp sensor that is located near the t-stat housing. On our 1987 models, the same location has the 50°C cold-shift softener switch (which I have disabled on my '87 to eliminate a cold shift flare.) It's odd that they didn't use the 2-prong, dual-function sensor at the head, near the glow plugs, as on all the 603.97x engines. 12) The KLIMA allows instant engagement of the AC compressor after starting the engine. The older KLIMA's, used on the OM602/603 engined 124/126/201 cars in the late 80's, didn't turn on the compressor until 10 seconds after startup. It doesn't sound like much, but on a hot day, this is VERY annoying. Luckily, the new KLIMA (used on all 124.128's) supercedes the old one, so you can upgrade your 1986/87 "10-second delay" relay with the new one for $50-$75 (used), or $180 (new). I did this to my '87 in summer 2007. 13) The glow plugs for the angled/inclined injection are 23mm, instead of the 25mm previous used on the 1987 vertical injection. Make sure you don't use 25mm plugs in the 90-up engine. 14) The timing chain showed 5° stretch (crank read 5° ATDC with cam at zero). With a new chain, it went to 3° advanced (BTDC). That makes NO sense, but indicates 8° of difference with the old vs new chain! I've never seen a 60x that had advanced cam timing with a new chain. Worn sprockets (or a shaved head) should *retard* cam timing, not advance it, so I'm at a loss for an explanation. Perhaps the TDC pointer is a bit off, and/or I'm not reading the scale properly. (?) Pretty likely to be operator error (i.e., me). I set IP timing to 14°. If you buy a 2.5T, make SURE you check the chain! 15) I had loud clatter when hot, like a bad lifter or three. Almost all the hydraulic lifters were at least partially collapsed. 10kmi of Mobil-1 didn't help the noise. So, I replaced all of them. And although it improved somewhat, I still had one loud tick-tick noise. It turned out to be a failing head gasket let debris into the upper oil galley, preventing proper oil flow to the lifters. A new head gasket, an cleaning the oil passages, cured the noise completely.