Hey all - I finally have a reason to join this forum, because I'm the proud new owner of an '84 300D!



Sorry for the blurry pic, I'll get some better ones up when the light's better.

I've been scanning classifieds, eBay, and Craigslist for about a year now. People don't like getting rid of these cars, it seems. Finally found one, about 150 miles away from me in Lake County (I'm located in Redding, CA). The paint's faded, and it appears that someone sprayed a clear coat without properly prepping the body, because it's coming off in sheets. The body's in pretty good shape, otherwise. One tiny dent on the truck is all I've been able to find. No rust. After I get the mechanics hammered out, I'll have some spray bombs mixed up to fix the fading - The hood seems to be the trouble area.

Replaced all the fuses and the air cleaner yesterday, also tightened the boot from the air cleaner to the turbo, spools a bit faster now.

Tonight I'm going to do a fluid change (oil, diff, tranny, brake), replace the brake pads, and check out the state of the vacuum system. The tranny shifts pretty hard from 1-2 and 2-3. What's the consensus on the shift points? I'll get the numbers off the tranny when it's on jackstands in a bit. It seems to shift at 3400/3500 right now, which seemed a little high to me, but I stumbled across a post somewhere that said 4k RPMs was right. I need to check out the vacuum system before messing with the Bowden cable none-the-less.

Is there a pictoral anywhere about cleaning the banjo bolt, etc?

If I can track down a valve cover gasket locally, I'll do the valves and check the timing chain tomorrow.

Got a power steering filter on order from Napa, so I'll flush and fill the power steering on Monday.

I was wondering if anyone could tell me what the 5 buttons to the right of the climate control wheel do? Seems like the indicators are missing, they've just got clear faces, which kinda has me scratching my head.


Is cavitation a problem on the OM617? I know some of the diesel engines from Cat, International, Cummins etc., are suppose to get SCA additives in the coolant. Not sure about this one.

Also, is there an online manual available for these cars? I've bought the licensed PDFs of the Ford shop manuals, haven't been able to find anything similar for the W123.

Pretty stoked I finally picked one of these up. I'm thinking about doing the EGR delete - I want to remove the ALDA and fit the car with EGT and boost gauges, but this car's destined to be my girlfriend's daily driver, so I figure I should probably keep that protection in place. The OM617 is quite a bit different than my 6.9l International IDI, all the mechanical systems seem much more refined.

-Apt

On the buttons -- they would be in your owner's manual. In case you don't have one, I'll post an explanation from mine.

I have a pushbutton unit that is toast with good buttons -- would you be interested in the buttons? I can ship them to you for the cost of shipping.

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Below is what the owner's manual says on the ACC system.

As for the manuals, check out STARTEK. Mercedes posts a lot of the manuals for their older cars there, and the W123 is there.

Attached Thumbnails

         

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

NO NO NO additives in the coolant. Only making a headache for yourself. Also, while you're at NAPA pick up Zerex G05 coolant. This is the coolant that these cars agree with and it is made by the same company who makes Benz coolant for half the price (Valvoline). I would just get the buttons from the junkyard, I doubt they would charge you anything except a $1,00 at max. Yes, I would look into adjusting the transmission also and checking the vacuum lines. Crucial in transmission shifting. This is all on the forum by the way.

Bajo bolts, easy. It's the bolt on the rear pass side of the engine with a "clear" tube running to it. You take it out and clean it and the tube if it's plugged.

Vacuum is your friend...

Pictorial of banjo bolt procedure:

Mercedes ALDA boost system service

Cavitation erosion is an issue in all Diesels. Zerex G05 antifreeze contains additives specifically to address this. If you can't find Zerex, then look for a precharged "fleet coolant". These are coolants specifically designed for Diesel engines, all parts stores should have a selection. Using a precharged coolant means you don't need additive packages. Unfortunately, anti-freeze is a religious issue in Benz circles...those who believe will scold you if you don't use G05.

I do add Water Wetter to all my cars. It helps a bit in hot weather.

For manuals and access to the parts book:

http://www.startekinfo.com/StarTek/ (portions of the site are pay-for)
http://epc.startekinfo.com/epc/ (free in the US)

I would suggest purchasing the shop manual CD either on E-Bay or from a vendor

The transmission on 123's shift more firmly than more modern cars, so it may be better than it feels at first. Shift quality is most affected by vacuum leaks...if you don't have a mityvac tester, get one. You are going to need it sooner or later. If you do an adjustment to the vacuum modulator, do it with a proper pressure gauge and get it right.


Good luck with it.

@ Jooseppi Luna: Thanks for the pics, clears things up. I'm going to scan some boneyards to see if there's a W123 locally. I might take you up on that offer, but I'm on a limited time frame ATM.

@jake12tech: Zerex, huh? Same brand I use in my International diesel, good to know.

@ngarover: That gives me a place to look - Thanks.

@Mxfrank: Thanks for the links. I check my IDI with SCA test strips - Should I do the same with the OM617? I picked up a Mityvac and vacuum/pressure gauge yesterday. I'm excited to use the Mityvac for bleeding my brakes. No more running a tube into a bottle into the cab and stomping the pedal while watching the fluid flow.

Got the oil and trans fluids & filters, fuel filter, and diff fluid changed yesterday night. The drain plugs on the diff were a pain to get off, I was beginning to think they were reverse threaded. 8-ton bottle jack pushing up on a 2ft breaker bar did the job. Gunna hit the brake bleeders with PB blaster again, do the brakes, and take it for a test drive! Then all I've gotta do is double check the tranny fluid level, and adjust the valves. Over the phone the parts guy at Napa said he'd have to order the valve cover gasket, but when I went in there he actually had one in stock.

Heres your manuals.....have fun!

Model 123 Maintenance Manual Index

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I'd reccomend adjusting the transmission shift points, then a valve adjustment, injector service, and check your timing.

If you want to go hog wild, get the updated primer pump and replace the driver's side motor mount-it's probably mushy and soaked with diesel.

After the timing has been checked, if it's still slow off the line you can gently adjust the ALDA a bit for better low rpm acceleration, without a smokescreen effect.

Also, the IP can put out enough fuel to burn roughly 12psi of air, so you can safety adjust the wastegate a little higher. Stock they were set at around 9psi.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment