madpogue
Full Access Member
You're supposed to plug the pothole with a Yaris before driving into it.....
Has anybody here had a 1984 Mercedes 300D?
- Thread starter burtcheca
- Start date
burtcheca
farmer/cabinetmaker
I thank each and everyone of you guys giving me good advices about the Mercedes. I made a mistake when stating the year, it's a 1981 300D. I bought it for $2,500. It had an algae problem in the tank for being parked for so long. I already treated that problem and after 12 inline filters or more I think is ending. The car is somehow sluggish and I posted the question on another thread. I have already put about 1000 miles in two weeks and it runs good once it reaches 50 or 60 MPH. It takes sometime to get there and maybe it needs some cleaning/tune in the transmission. I need to find a shop that will be able to check timing, valves, etc. There are not many mechanics around here that know about diesel Mercedes. Thanks again. If I find my way through the steps to post a picture I'm going to add some soon.
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NO_SPRK
User & Abuser
...im sorry
That zf slushbox used on european diesels can have issues that can fake you out and seem like engine power issues, and it makes zero sense, but before you beat your head against a wall, grab a can of the high end Trans X and dump it in the tranny. THe things suffer from sluggish valve bodies and varnished up clutches that can rob you of power when trying to get moving.
Next grab three cans of Liqui -Moly Diesel Purge and do the treatment on the pump and injectors ( do a search on the stuff, it doesnt go in the tank, you will need to re route some hoses )
The car may feel quite different after that.
One thing about Merc diesels , is trying to find information, if you go looking around MB forums, you will discover something REAL fast. They are all heavily populated with a bunch of deep pocketed bench racers who spend a lot of time reading magizines and will sit around arguing specs etc like they have some idea as to what the heck they are talking about, but in fact, they ALL take their cars in to a mechanic somewhere and pay to have everyuthing done and most dont own anything more advanced than their wife's pink sewing machine tool kit. Same goes for BMW forums so finding any real useful information can be a good trick, you basically need to invest in some good manuals and get to know the folks at the dealer , I've found their parts guys to be real helpful and their mechanics very generous with spares
Heck around here teh MB dealer is cheaper than internet aftermarket for parts, now THAT is a real shocker, and Ive had teh parts guy go and beg me little individual bits that normally only come in kits frrom the varios guys on the line and they've always been happy to help. MB like to see a LOT of their old cars running around, and they dont care how it gets done
Next grab three cans of Liqui -Moly Diesel Purge and do the treatment on the pump and injectors ( do a search on the stuff, it doesnt go in the tank, you will need to re route some hoses )
The car may feel quite different after that.
One thing about Merc diesels , is trying to find information, if you go looking around MB forums, you will discover something REAL fast. They are all heavily populated with a bunch of deep pocketed bench racers who spend a lot of time reading magizines and will sit around arguing specs etc like they have some idea as to what the heck they are talking about, but in fact, they ALL take their cars in to a mechanic somewhere and pay to have everyuthing done and most dont own anything more advanced than their wife's pink sewing machine tool kit. Same goes for BMW forums so finding any real useful information can be a good trick, you basically need to invest in some good manuals and get to know the folks at the dealer , I've found their parts guys to be real helpful and their mechanics very generous with spares
Heck around here teh MB dealer is cheaper than internet aftermarket for parts, now THAT is a real shocker, and Ive had teh parts guy go and beg me little individual bits that normally only come in kits frrom the varios guys on the line and they've always been happy to help. MB like to see a LOT of their old cars running around, and they dont care how it gets done 
I can have my son walk you through some maintenance procedures, he knows these cars inside and out. And does not have deep pockets. The timing should never change, fuel filters make a huge difference on these cars.
He had a hot 300sd that impressed even me. the na cars are not as peppy but they will get down the road, the pump can be tweaked a little. IIRC.
He had a hot 300sd that impressed even me. the na cars are not as peppy but they will get down the road, the pump can be tweaked a little. IIRC.
burtcheca
farmer/cabinetmaker
I made a mistake when stating the year, it's a 1981 Mercedes 300D.
I really appreciate if your son can help me fix some problems I have with this car. It's hard to stop the engine sometimes and shakes like crazy just before stopping, it's kind of slow and it takes sometimes to reach some speed. I'm treating an algae problem in the tank and it's getting better now.
Thanks for your reply.
Burt.
I really appreciate if your son can help me fix some problems I have with this car. It's hard to stop the engine sometimes and shakes like crazy just before stopping, it's kind of slow and it takes sometimes to reach some speed. I'm treating an algae problem in the tank and it's getting better now.
Thanks for your reply.
Burt.
Brandon314159
Registered User
Lots of useful good data on this tread. Some misguided information too. Be forewarned.
300D (a w123 body) came with both a 617.192 and it's non-turbo variant. http://en.wikipedia.org/wiki/Mercedes-Benz_300 Anything after 1982 will have the 722.3 transmission (It's not a ZF BTW) and they are BULLETPROOF if you keep horsepower below the factory 5.0L high compression V8 powered cars outputs (bumping 300HP/~250-300ft/lbs torque for the Euro Models). This is the same transmission put into some V8 powered Porsche vehicles (except they divorced the gearbox from the torque converter).
The w123 and the w126 (300D, 300SD) were the last hand-built bodied cars that Mercedes made and it shows. Very high quality build and easy to maintain even with the most basic tools. ~123HP and plenty of torque to push you down the road in stock form. They will get you in trouble because 95MPH feels and sounds the same as 95MPH (except for the engine purring away under the hood).
If you put anything but Type F fluid in your transmission you WILL ruin it. I've rebuilt a couple of them and the miles on my four 722.3 automatics in a 1987 300TDT, 1982 300SD, 1981 300SD, and 1984 300SD all individually had more miles on them than I've seen any sedan or truck automatic pull off without a rebuild. The biggest failure I've seen is someone dumping crap down the fill-tube to try and solve a problem that would have been fixed with a fresh filter and new fluid. Pretty sad.
Best things to perform if you want to make sure it's up to *****:
Fuel Filter
Air Filter
Check Fuel Tank Vent for Plugging
Service Transmission (filter/gasket). Very easy to do
For turbo models (if yours still has the original 300D TURBO DIESEL engine:
Clean ALDA Tube from Injection pump to Intake Manifold Runner
Adjust ALDA for maximum fuel (avoid heavy smoke on acceleration)
Confirm Boost Pressure (check at the ALDA line). Should be 11-13psi.
All pretty simple stuff to DIY and don't let the nay-sayers here get you down, they're far better built vehicles than you can buy today. They don't have all the bells and whistles but they will get you safely down the road. I have lots of you-tube videos under the same username of my prior modified 300SD. I used to be heavily involved in the Mercedes diesel engine forums (both as a user and a moderator) but all the arguments and nay-sayers got old so I moved off to doing my own stuff and posting it on my own website. Lots of great info on youtube about how to do maintenance and the parts are very cheap (just stay away from the dealerships)
Hopefully you get to enjoy driving one!
Cheers,
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Brandon314159
Registered User
The non-turbo engine isn't shabby (right around 80HP). It won't pull like a big-dog like the turbo model will but it does get you around. The earlier 300D (found in the w115 bodied cars) has one less crank main journal and it shows (they don't often make it much past 300K except in rare cases). Your engine is very solidly build and can EASILY (if you maintain it) last well beyond 500Kmiles (I have a car that approaching 600K with the turbo variant of that same engine).
Your car may or may not have the 722.3. If the oil pan on the transmission has 4 bolts, it's a 722.1. If it has 6 bolts, it's a 722.3.
If you have a 722.1, start looking for a 722.3 now because you will need it some-day. They can be had in good condition for about $200-300 bucks used on craigslist regularly. Check the fluid before buying (sniff test it for burnt ATF). Unfortunately the 722.1 just isn't a solidly build transmission compared to the engine and the body of the vehicle.
Clear that algae out of the tank with some BioBor, change the filters (a bunch) and you'll have a sweet running machine. It should get 0-60MPH within 18-20seconds so if it's creeping, keep hunting for what's wrong.
There is a drain on the tank under the car that you can empty the tank if you decide to clean it out. If you remove the fuel level sender (behind the rear seat under a plastic plug, you'll need a 42mm socket) you can see right into the fuel tank with a flashlight to see whats going on in there. Clean the sender while you are in there (it's a long tube with a fragile sliding piece). They rarely fail, but often get algae in them and stop indicating properly.
If the engine shakes on shutdown, you're system vacuum might be weak, making the shutdown too slow. Once you shut off the key it should stop within 1-2 seconds. Vacuum leaks will suck up a lot of your time so google around for a diagram.
Take care!
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ah1988ford
Full Access Member
The mercedes are pretty simple when you learn the basics, the valve adjustmenst are super easy you have a feeler guage and turn a set of wrenches.
Check out "mercedessource" on youtube he has a TON of tech vids on these diesels. Check his website out he sells a repair kit for everything and every kit comes with the tools parts and manuals to do it, at a pretty good price too. There is probably something going on with the vaccume system if your car dosent shut off right away, the shutoff is controlled by a vaccume module on the ip. He has a vid on how to test that on youtube check it out.
There is also a screen in the fuel tank that stops large particles from going through the sending unit, it will cause lack of power if it is clogged with algae because of restiction. He has a vid on that too.
ah1988ford
Full Access Member
Im bored I found them for you
check the first and last vid for sure.
http://www.youtube.com/watch?v=IbYMo4HafGY
http://www.youtube.com/watch?v=QgWIX2DQo1k
http://www.youtube.com/watch?v=i4cVXrfGF6Q
http://www.youtube.com/watch?v=QmxZLerwDOY
check the first and last vid for sure.
http://www.youtube.com/watch?v=IbYMo4HafGY
http://www.youtube.com/watch?v=QgWIX2DQo1k
http://www.youtube.com/watch?v=i4cVXrfGF6Q
http://www.youtube.com/watch?v=QmxZLerwDOY
NO_SPRK
User & Abuser
i thought bmw used ZF... MB makes their own automatic. unless ZF really made it and never put a badge on
Ive had to go deep into a number of those things on mine and a bunch of customer cars, , those older critters were zf. , a lot of times the parts when purchased from MB would come out of an MB box and be in a ZF bag inside. A lot of the zf slushbozes were cable shift activated, but the MB had a combination setup thats all funky and goeas out of what at teh drop of a hat, but when it works right, it shifts really smooth,
Also to the original poster, that box is intended to have you floor the thing if you want it to take off quickly,, if you dont completely floor it, the thing generally wont drop all the way down to low, its meant for smooth takeoff under most conditions without a jerky extra shift. If you are driving it a tad too conservatively that may have something to do with the low power until highway speed feeling.
Kevin 007
Full-floater
My favorite MB is the W123 OE616 240D with the manual trans. I have driven my share of 300D and SD's and don't get me wrong, they were great. But that tight manual gearbox of the 240D was something else!!!
With the manual box, those things are downright peppy. Its nice not being stuck with that factory shifting arrangement on the slushboxes, they did that on the slushboxes really for 2 reasons, for smoothness, and for safety driving in snow, its really hard to break the tires loose and they track like glue, but they act sluggish if you dont beat them hard, The stick, lets you wind them up nicely and they will act like little rockets. Keeps the injectors from loading up too.
Kevin 007
Full-floater
And I feel they are less upkeep and more reliable to. And the 616 seems to get a touch better mpg then the 617. Probably mostly due to the manual box
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