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I think what you said here is very true, Shifty. The Mercedes diesels gained their deserved reputations at a time when most cars were not well built, and 100,000 miles, and certainly 125,000, was a real milestone. I remember when my uncle uncorked a bottle of champagne when his trusty Plymouth six turned 100,000. It was cause for celebration. Today, most (or maybe all) cars can achieve double these mileage figures, given reasonable care, and especially with synthetic oil. Therefore, today you choose a new luxury model for its styling, performance, comfort, features and exclusivity rather than for longevity. In terms of mid '70s-mid '80s cars, the Mercedes diesels really stand out, for the reasons you mentioned, and for their tasteful styling and charm. Today, an old $2,000-$4,000 Mercedes differentiates you from the sea of all-very-similar mass market car owners, and sends the message that you've beaten the odds. Whereas I don't pay attention to ordinary cars, I always take note of the old Mercedes. Well, okay, like most of you, I presume, I take note of all old cars, not just Mercedes, The difference is that an old Mercedes prompts a "Gee, it would be nice to own that" thought, whereas an old Corolla doesn't.
Actually an old Benz diesel is not for everyone; if you don't get the turbo model, the old 300Ds can be dangerously slow, to the point of producing a great deal of anxiety in the driver. Also, unless the engines are in tip top shape, they puke out lots of fumes and many other drivers do not find them so charming if they are following behind.
They also leak a lot, so I was banned from most people's driveways. I felt like a leper. And mine was a NICE car---but it didn't pass muster in suburbia.
The real problem with many old luxury cars is, of course, that they fall into hands of people who can afford to buy them, because they are cheap, but cannot afford to maintain them, because that is not cheap. I know one couple who have the most clapped out, smoking, rattling, beat-up old Benz diesel you could imagine, with marginal tires, wired up exhaust, broken windows---but all they do is putt-putt to the grocery store 3X a week at 32 mph.
The car refuses to die although I suspect it would like to. :P
The valve adjustment is just a matter of having the right "crowsfoot" tool (not that expensive) and being able to turn the engine over by hand or with a remote starter and using a feeler gauge. Maybe your public library has a book on this, a Haynes or Chilton's. You just do one cylinder at a time, making sure each cylinder is at top dead center, that is, both intake and exhaust valves are closed and not touching the cam lobes.
1. The car changes gears very hard and often "clangs" into overdrive. Is this due to a vacuum modulator?
2.There is also a plastic cam like piece on top of the valve cover that rides against two small wheels. The wheels are worn out. Is this a valve that controls the vacuum to the transmission? What is this called?
3. The motor surges at idle,if in gear it runs smooth. Is this normal for mileage and just a characteristic?
Thanks for your help
Any car on earth can go 400K miles, even a Yugo. All you have to do is keep pouring money into it. I think you will find that any old 300D with 400K has a lot of investment in it.
What is remarkable about them is their build quality. Where most cars literally fall apart at 400K, a 300D can still look good, not rattle and not shred its interior. But that doesn't mean they don't break down mechanically or wear out just like any other car.
Your average taxi cab can run as long as a Benz but it won't look at good, is my point.
As for things to look out for:
NEGLECT -- greasy oily engine, rusted body, dents, mildew, balding tires, filthy trunk, broken lenses, etc. Stay away from cars like this
ENGINE -- many 300D engines are tired. Look for danger signs such as lots of oil in the air filter (blow-by) and hard starting when cold. A 300D engine should a) start up quickly and b) peg the oil pressure gauge when cold---that oil needle should literally click as it hits the highest number and the needle stop
NOISE-- a rattly engine, noisier than usual (they aren't very quiet normally) could mean bad injectors.
SMOKE -- 300Ds smoke a bit on acceleration but it should NOT be clouds of noxious smoke. This could be bad injectors or bad injection pump timing.
HEAT/AC --- notoriously unreliable controls. check for ALL functions before you buy.
CRUISE CONTROL -- notoriously unreliable. Almost always a bad amplifier located behind the console. About $100 to rebuild + labor.
REAR SUSPENSION -- sagging back end, front end up in the air? You have a failed hydro-pneumatic compensator. Fairly big bucks.
CLUNKING ON TURNS? -- bad CV joints in the rear axles
HARD SHIFTING -- hard shifting is normal. Buy a neck brace, you'll need it. But LATE shifting could mean a vacuum leak or bad vacuum modulator
DOOR LOCKS -- these are vacuum operated by little motors in the door panels. They often get slow. The motors are rebuildable and don't cost too much.
BEST CAR TO BUY? --- Definitely choose the TURBO models. Do not pay extra for the coupe, they aren't worth more and they are less practical.
MAINTENANCE --
always use fuel conditioner every fill up
use anti-gel for the fuel in cold weather
change your fuel filters (two of them) FREQUENTLY
make sure the valves have been adjusted at least once in the last 30K miles
change the oil every 3,000 miles come hell or high water
FUEL MILEAGE -- you will hear all sorts of silly claims but in fact you will get about 18-22 mpg city driving and about 22-26 highway driving
TOP SPEED -- diesels this old don't like to rev. 75--80 mph MAX is more than enough for this car. Drive faster and you'll crack the cylinder head sooner or later.
PARTS-- lots of stuff on the Internet, and the MB dealer still carries an amazing number of parts for this car
REPAIR MANUALS -- you can't beat the 3-volume factory manuals, but you'll pay over $300 for them.
SPECIAL REPAIRS -- you cannot work on the fuel injection pump. This goes to a specialist and costs about $1,500 to repair. They are very rugged and should be fine if nobody messes with them.
Good hunting!
if it isn't a bad line, i would suggest that your fuel heater loop, which may not exist on earlier models could be introducing air through a bad o-ring.. i eliminated this fuel heat loop, which simply keeps a small amount of fuel warm when the block heater is utilized. it has a small fuel jacket that runs a small around of fuel into the block, it's really not necessary unless it gets well below 0, even then i've not had any difficulty in cold weather with out it!!
hope this helps
brett
aircraft maint
fix everything else that breaks tech
Your car doesn't even have a computerized engine management system. That was weird advice for an '84 300TD.....oh well.....
I guess to be sure you can have it towed to a Mercedes diesel specialist and pay the diagnostic fees. We aren't with you so we can't hear what you're hearing. If the engine is ruined, I think you just have to let the car go or buy another one just like it.
(1) Redline products are mentioned quite often as having the best fuel additives but rarely, if ever, is a specific one mentioned. For example, there is RL Anti-Gel, Redline 85 Plus, etc. Of the many Redline products, which is the best or most recommended for use in a 1985 Turbo.
(2) Many come in a winterized version. How do I identify it?
(3) What is "pour point"?
After reading the posts I'm certain that I need fuel additives. I just don't know which one(s).
I live in Massachusetts where so far most nights have been below 20 degrees F. Daily temperatures may reach 45 degrees but are usually at the freezing mark.
I have a block heater but I'm not sure it works. Most mornings it will not start. When the temperature rises to 45-50 degrees it does. Unfortunately, it sits in my driveway and for the past two weeks we have had a lot of snow.
I'm new to diesel automobiles and I need a lot of help.
Thanks
Also you have to change glow plugs every few years, just like spark plugs, or you won't start up very well in cold weather.
The block heater is an excellent idea for you and you should investigate how to get it operative. I presume this is a WATER heater, not an oil heater. But if it doesn't work, just keep the battery warm with an electric heating pad isn't a bad idea, or putting a shop light under the engine to warm it up a bit.
Also, sometimes glow plugs can come up to temperature quickly (8 seconds), so you need to be more specific than "right out". Depending on your climate and season, the glow plugs may come up to temp fast and not need to be on for long. If you are trying to start the car at 60 F or higher, it should start without the plugs, FYI. Let us know...
zak
1985 300td
195,000 miles
WVO converted
10,000 miles
2. If the battery and glow plugs are good, Is the ignition gone? I put in a generic one after using the screwdriver for a bit, when I took out the old one!
3. When my 1983 almost stopped (max speed was 20 km) while I was driving, it was a totally dirty transmission filter, which should be changed occasionally. After sitting all night, enough drained through to start it in the am, but soon after same thing happened. The mechanic topped up my filter!!Not good, had to change it.
4. Good luck! These are good cars.
If anybody has any suggestions on what type and best place to buy it let me know
Thanks
You'll probably want the factory engine manual if you are going to tackle all this, and of course, a good machine shop to rebuild the used head.
Sounds to me like your best bet is to find a good low-mileage engine, which isn't a small task for this age of car. With 240K I'm not sure it's worth rebuilding this engine, especially with possibly catastrophic damage lurking somewhere else.
I'm not an expert on diesels, is the cam tower casting a seperate part from the head like on the old straight six gas engine?
Unless the owner is rich and a masochist, this engine would seem to be toast. You might as well pull the head and see what happened to the pistons. Might there be a small possibility that a replacement head would do it??
Thanks for the help!