Project Smokey Wagon 2014! - Mostly just noob questions inside. W123 1985 300TD - PeachParts Mercedes-Benz Forum

WarTowels · #1 12-04-2014, 12:21 AM

I'm the new owner of this lass 1985 300TD : (http://www.peachparts.com/shopforum/mercedes-cars-sale/362629-fs-1985-300td-maine.html).

I went from looking at a winter car to looking for a 300d... to looking for a 300TD. This is a second car/winter car / yet another thing to learn and tinker on.

I'll throw up some more pictures after I've cleaned it up, several on that FS thread.

This post will also serve as a bit of a record for myself and perhaps others.

I'm new to both diesels and Mercedes with all of my past cars being Japanese (I've only ever had Honda, Toyota, Mitsu, Infiniti and Nissans). So much research is ahead of me and this forum will be a great resource.

My goal right now is just to get the car inspected and on the road, followed by returning it back to stock and fixing/improving a 29 year old car.

Issues I'm aware of that need resolution before inspection:
(Any help is welcome!)

- Tires:

Starting to get cracks and have been sitting / will replace with dedicated winters soon

- Dash Cluster:

Tach dead, gas gauge intermittent, no lights on the cluster except: brake light, brake wear light and battery light are all illuminated full time with varying brightness dependent on engine load.

- Sagging rear end / bouncy rear springs:

Rear end is sagging down quite a bit (haven't measured yet, but clearly way too low). The rear is quite bouncy as well. Given those conditions and from my research that should indicate the springs need replacing. No clue if the SLS is operational and to what degree, but I believe I'll need to get replacement springs in there in order to find out.

Will update more as time goes on!

vstech · #2 12-04-2014, 08:13 AM

were you looking for a veggie burner?

the CA air filter arrangement on there, mmm fun.

t walgamuth · #3 12-04-2014, 09:25 AM

Looks like a nice car! Rare color I think.

WarTowels · #4 12-04-2014, 09:58 AM

I don't have any interest or availability to run biodiesel, I'd like to understand the system better and potentially return it to stock.

As for the color, I think it was originally gold and has since been repainted 444.

dieselbenz1 · #5 12-04-2014, 10:02 AM

Nice looking car. Bouncy rear indicates your accumulators may have a leak and need replacing. With a new set of springs on the rear the ride quality goes way up on these wagons. Enjoy your new ride!

WarTowels · #6 12-04-2014, 10:19 AM

Should I purchase the Mercedes Source guide on the SLS system?

I'd like to try and diagnose it properly before throwing money at it and I'm unsure if I should start with springs or accumulators. My plan was springs and then see where it's at...

I suspect and will do some testing today, but I think the alternator may be dead. It sounds like the bearings in the alternator are dying and creating a lovely whine. In addition the brand new battery was unable to start the car after a day or so of sitting and after a long drive the day before. So I suspect the alternator may be causing the idiot light and not charging.

fahrvergnugen · #7 12-04-2014, 10:35 AM

The Mercedes Source guide is excellent, and makes perfect sense; I purchased it, but have yet to do as it suggests, low monies... I have a new pair of accumulators to install, and my SLS valve in the back is leaking, there is a guy here that sells a kit to rebuild it. I figure I will rebuild the pump at the same time, flush the system and be good. I'd like to get new springs as well, as mine has 205K on it so I am sure it is due. Also, I know that the rear subframe bushings are bad, not looking forward to that repair.

If you are so inclined, the early 90s Saab 9000s had a 115 amp alternator that will bolt in, but you will have to modify the wiring from the OE plug to ring terminals, and possibly upgrade the wiring.

WarTowels · #8 12-04-2014, 10:43 AM

115's quite a bit more eh, I think the stock is what 65? 75?

I'll have to do a search for a guide on what's different/what needs changing. Looks like the Saab alternator is cheaper than the Merc so the difference could be spent on wiring and I wouldn't feel too bad especially if it fixes my issue!

Carpenterman · #9 12-04-2014, 10:59 AM

Replace the accumulators first, then see how you like the ride before replacing the springs.

If you want to test the old ones first, remove the center fitting and poke a pencil in the hole. If it goes in more than about an inch and a half, they are shot.

If the rear end still sags, you may need to adjust the valve. If the rear end loses height overnight, then rebuild the valve.

ROLLGUY · #10 12-04-2014, 11:33 AM

Welcome, and please post more photos. We like photos here. There are so many knowledgeable folks here, you will find that you need not go anywhere else for info on how to repair/upgrade your car......Rich

WarTowels · #11 12-04-2014, 11:39 AM

Thanks for the welcome guys/gals. I really appreciate it!

I'm trying to clean up a little bit of the car in addition to tinkering and diagnosing the issues. So the for sale pictures will have to suffice for a few, but when I get some time maybe this weekend I will take updated pictures of the cleaned up bits and more as I go.

Also first post has the issues I want to resolve for inspection- I have a gazillion more questions about the car and the bio system which some of you may be familiar with. Expect a lot of "What is this!?" posts in the future!

What's the best shop manual to get? Physical or digital?

uberwasser · #12 12-04-2014, 11:53 AM

You can get by, for the most part, with the free online service manual available at startekinfo.com (Mercedes provides this resource).

Click through >> MB Workshop Resources > Service Manual Library CD/DVD > Model 123 Service Library > Disc 2 > Wait for the silly intro to finish > click Accept > Click continue > then select model and year.

From there you can choose to browse the indexes for the Engine Manual, Chassis manual, etc.

ROLLGUY · #13 12-04-2014, 12:02 PM

As far as the WVO system is concerned, it looks like a Lovecraft (most popular in a CA car), and is not needed. I ditched all the WVO equipment on my cars years ago, even though I am in So. Cal. I agree with your plan to go back to stock. If you ever plan to run any kind of Biofuel, convert the fuel, not the car. B100, blending, solvent thinning etc. are ways to convert the fuel, and no equipment or modification to the car is needed whatsoever. In fact, the engine bay of a TD is packed already and the addition of alternative fuel system equipment just makes it harder to work on. Once you remove all the equipment, advertize it for sale, as I am sure someone will want it (not me of course)......Rich

toomany MBZ · #14 12-04-2014, 12:05 PM

Welcome.

Dead tach may be a blown fuse on the OVP relay.

See pics, the location is a generalization.

Dash lights are probably a failed/failing rheostat, or the dimmer switch, also when pushed resets the trip odo. Spin it a few times, they may light up, albeit dimly at best. It's possible to jumper the two leads, so when the lights are turned on, they'll be full bright all the time, again, they're dim at best.

The SLS has been covered.

Keep us posted.

WarTowels · #15 12-04-2014, 12:08 PM

Haha thanks, I will need to do a bunch of reading on what was changed and what can be left/bypassed or returned to stock.

Right now there is some electric pump that seems to come on with the key in the ignition in the ON position and another pump on the passenger side or some sort. Lots of learning to do.

Cheers,

Greg