Considering purchase of a 1987 300D, what to look for?
 

Hi guys, I've had my eye on a '87 300D, but to be honest, I don't really know much about the vehicles (weaknesses, specs, etc), so, I'd like to educate myself before the car is looked at. My girlfriend is going to look at the car before me (I'm not in the area), and she'll take pictures for me to inspect.

1. What engine is it (OM603?) Are there any "troublesome" engine numberings / castings?
2. What is a typical yearly maintenance routine (belts / valves / glow plugs / nozzles / just oil changes / etc)?
3. What kinds of long term maintenance things should I be aware of?
4. Is the W124 chassis prone to rust? If so, what areas should I look at?
5. How does the climate control system function? Is it automatic or manual? Anything to look out for there?
6. Is there anything I should be aware of coming from a W123?
7. Anything else I've missed?

Thanks for the help,

Nate

I hate to post when my experience is limited to reading the forum, but I need the practice so I can try and help the regulars that might get tired of answering the same questions. I think much of this information can be had by doing a search or two.

I also think this is a very desirable car for its power, and I believe it was the fastest mercedes diesel until 1998's turbodiesel.

I think the typical W123 vs. W124 repair cost argument goes something like... the 124 is more expensive to maintain and more difficult to DIY, but there is a wealth of knowledge and expertise here so things can get done with only your ability as a DIY'r and access to tools, parts, money, and time to limit you.

I'd say weak points are the cylinder heads and AC. I think the #14 head is the most prone, but depending on mileage may have been replaced.

I think AC systems are problematic in most ACC equipped MB's.

Sunroof repairs can be expensive.

Rust seems to be the real killer, so yes I think it's important you examine the car closely and even more importantly pay the going rate for a qualified person to give the car a thorough inspection.

Hope I didn't make too many mistakes. Good luck!

Sorry for all the general questions, I just felt like I didn't know where to look. I'll definitely have a mechanic look at it before I hand over any money. I'll definitely look at the head. In the meanwhile, I'll poke around on the forum.

Thanks for your time :)

Look for excessive cooling system pressure. Sign of head or gasket failure.

Check for excessive blowby in the crankcase (pull the oil fill cap while running) Sign of bad rings.

Look for white smoke in the exhaust. Another head problem indicator.

Do the lifters "tick" excessively. If so, it will bother you later when everything else is fixed.

Bounce the rear end and listen for squeaks (carrier bushings)

Run the heat/ac selector through the cycle. See if the air comes out of different vents as it should.

Check the sun roof operation. Expensive to fix.

Check the jack holes for rust. Look very closely.

Check the under body for rust. You're in the rustbelt.

Operate ALL the windows to check the mechanism.

Pay attention as to how the tranny shifts. Does it shift crisply, or does it slowly slide from gear to gear. Crisp is better.

Check all of your rubber suspension components for newness. If they are original, they need to be replaced. 22 year old rubber is past due.

Check any repair receipts to give you an indication of how thorough the previous owner was with the maintenance.

I'm sure there are many other things to look at that are no different than any other 22 year old car. I wish I had checked some of the ones I listed prior to purchasing my 87 300d.

After you read this, do a search and you will find most everything you need.

Not everyone will agree with me but . . .
 

The '87 300D is a joy to drive. More powerful and better handling than the older W123 cars with their less-powerful OM617 engines, more fuel-efficient and aerodynamic, the '87 300D (W124, OM603) was the first "modern" Mercedes diesel. The body style was copied by almost everyone and still looks "new" today. A typical car will get 25 MPG around town and 30 MPG on the road. YMMV.

Mercedes started selling 124 gassers in Germany in 1985 and brought them to the USA in 1986. For 1987 the OM603 diesel engine was introduced. The engine came with an alloy head that was (and still is) more susceptible to cracking if the engine is overheated than are the older iron-head engines. Improvements were made to both the head and the head gasket and the later versions were sturdier but it is still wise to keep an eye on the coolant temp gauge and not "try to make it home" if it starts to climb above 110C or thereabouts.

The oldest head has a part number with a "14" in it, later models were "17" and "20" and the last one had a "22." I would not necessarily avoid a car with a #14 head but given a choice, take the later version. You might consider using as a bargaining tool the possession of a #14 head. My car has a #14 head and I have no problems with it. However, the cooling system is in good condition and I keep an eye on it.

I have never heard why Mercedes dropped the 603 engine after the 1987 model year. It may have been because of the head problems or because of tightening smog regulations. In about 1990 they came out with a version that had a 5-cylinder turbodiesel, the OM602. The last W124, in 1995, had the OM606 6-cylinder normally-aspirated engine. As the years passed, the W124 got more and more electronics. The earlier models are therefore simpler and easier to care for.

There are a number of things that are easy to overlook but very expensive to repair in this car. They are: cracked head or blown gasket, suspension (under the car, problems are easy to hide), climate control system (sellers always say "it just needs to be recharged"), sunroof (the W124 came with the first slide/tilt sunroof and there were some design problems). These items can amount to thousands of dollars. Each. The cruise control is another common failure point but is less expensive to repair. You can get a rebuilt "brain" for about $300.

On the other hand, there are parts of these systems that you can fix yourself. With your own labor and also saving money by buying from FastLane, you can fix some parts of the suspension and the climate control yourself. The sunroof is a bigger challenge, not a DIY job for most of us, but you can live without it. You can change the oil and the fuel filters and the glow plugs yourself. You can replace light bulbs and patch broken wires.

I am seeing many W124 gassers (300E) in the junkyards now. Since the body of the gassers is the same as the diesels, this means lots of inexpensive body, interior, and trim parts are available.

The W124 chassis has far more in the way of creature comforts than the older cars; this also means more to repair. The '87 300D has ABS and a driver's air bag. It has power seats (with driver's seat memory) and retractable rear headrests.

Some people are good at repairs, others avoid them like the plague. This is a personal choice that you will have to make for yourself. If you have to hire someone to do repairs for you and pay full list price for all the parts, you will quickly learn why we say that there is no such thing as a "cheap" Mercedes. You can save at least half by learning to do the work yourself.

The '87 300D has the 722.4 4-speed mechanical automatic transmission first introduced in the last W123 cars. It is a good transmission and is generally very reliable. Lifetime is usually 200,000 miles or more. It is about as expensive to overhaul as most other automatic transmissions and is not a DIY job for most of us.

Much more information is available here via the search function. Good luck with your shopping. Have a professional inspect anything you're seriously thinking of buying. A hundred bucks will save you thousands of dollars of grief (ask me how I know).

Jeremy

Thanks for the insight guys, I'll have my girlfriend write down the head casting number. Is there an easy way to describe to her where she can see it from? She's not too keen on engine components and I'm not too familiar with the layout yet. Is she going to need a mirror to see around anything?

If the preliminary photos and questions go well, I'll have it checked out by a mechanic. Are there any specific things they might not normally do that I'll ask them to look for? I don't mind paying a little more to have them check the pressure in the A/C system, check the coolant pressure hot and cold, maybe even do a compression test..? That should be worth my money, correct?

The car is a single owner car and is priced right about what I would pay for a solid vehicle ($5k). I expect a rather large list of documented repairs in it's long history. :)

The price is on the high end. They are desirable cars among the knowing, but don't command much of a selling price.

The 603 was dropped largely because of marketing. There wasn't much demand in the US for diesels during that era (thanks GM). And in the '90s, the smaller engine was put in the 124 so that it wouldn't out-perform the flagship S-class diesel. A very common tactic among German marques.

Thanks for the explanation, Jeff.

my #14 head has 478,000 miles on it.

Head number
 

The head number is cast in the aluminum. It is on the left (driver's) side of the head and almost exactly under the air pipe that crosses over the valve cover. You don't need a mirror but a bright flashlight will help and hope that there's not too much oil and dirt. You have to look between the injector hard lines and see a little bit of the number, then shift your view and see a little bit more. The number should be 603 016 xx 01 where xx is the head revision number. AFAIK, the choices for "xx" are 14, 17, 20, and 22. The "603" means it was first used in the 603 engine; the "016" means it is part of the air intake system, and the "xx" means the revision number. I forget what the final 01 is and it could be some other number too.

Jeremy

You may want to read this.

I have 2.
87 300D
87 300TD

Both of mine have the 14 head. The guy that sold me the 300D told me to change the belt and belt tensioner every 3 years, weather it needs it or not.
I have heeded his advice. one has about 225,000 and the other 210,000 miles.

These cars can turn on a dime. With good tires and suspension components you can make a u turn at 35 mph. These have lots of rubber bits in the suspension. If it doesnt have nice tight handling, some of these rubber bits need to be replaced. None of them are expensive, and most are not difficult to replace yourself. In the rust belt the rubber parts last a long time.

Rust is not near the issue on a 124 as it is on a 123, or some say even a 210.
Cost was not an object on building these, and the build quality is excellent.

Parts have been cheap,rebuilt starter $150, caliper $45, brake pads $30.
W210 rims bolt on for an updated look, and good tire options. Euro style Depot lights can be had on ebay for $150.

i drive mine like i stole it, every single day, and it always puts a smile on my face.

Ok, I had a lengthy conversation with the owner about the vehicle. Let me know if anything really sticks out as a deal breaker.

1. The owner is actually the second owner. He bought it from the original owner's son last November.
2. He's selling it because he has another vehicle and doesn't need two cars. He just uses it for commuting now.
3. Response to known problems: slow leak at the pinion seal (?), when he bought the car the shop that checked it out said the front struts could be replaced in the future.
4. Cooling system: the radiator had developed a hole, and was promptly replaced. He said it's never had any trouble with operating temperature. Mainly driven on the highway in his ownership.
5. Oil leaks: small, slow leak at the turbo. No noticeable oil consumption.
6. A/C: blows ice cubes, couldn't give a definitive answer if it was still R12 (I would assume so, as he said it works surprisingly well).
7. Sunroof: previous owner said it didn't work. His son tried it and they had to close it manually.
8. Front power windows work, rear do not (shop said it was the actuator arms that needed replacing).
9. Power seats work flawlessly. Drivers seat has wear (expected). Says the interior is in surprisingly good condition.
10. No smoke in exhaust. He said there might be a little if your really stomped on it. He also said there was a little bluish smoke while starting before he had the glow plugs replaced, now, none (is that regular?).
11. Trap oxidizer: no clue, said he doesn't recall seeing it.
12. Suspension: had rear control arm and rear bushings replaced.
13. Major services: transmission was rebuilt by previous owner, unknown time, he says it shifts solidly but smoothly.
14. Any rust: says there is absolutely none. He believes that the car was garaged by the previous owner (VA car all it's life). Paint is excellent.
15. Service records: all from his ownership.
16. Recent work: new battery and alternator, tires and brakes.

If he doesn't sell it, he says he'll just keep driving it on his 30 mile commute.

The sunroof can be expensive to repair but you can live without it. The rear window regulators you can learn how to replace yourself. If the trap oxidizer hasn't already been replaced, the factory recall campaign is still in effect and any dealer will do the job for you free. You might even get a new exhaust system out of it. Front shocks (struts) you can learn to do yourself. Nothing else looks worrisome. Have a shop look it over for you and then buy it.

That is a little too many items to justify a $5,000 price. Other then that, i agree with the poster above. $3500 - $4000 would be a fair price if there is zero rust and its a good runner.

yeah i'd say 3.5-4k price range, unless body and int are really good.

mines got 290k on 14 head.

couple things based on what you mentioned :

was that rad replaced with a Behr unit, or Nissen? You would only want Behr and those things are pricey. Not bad to RR, but $350 last i checked. Behr has the metal outlet sleeves, very important. Nissen is all plastic.

as for what ive seen "common failures" on mine -

igntion lock mechanism froze up, needed a tow and about 5 hrs of my time to RR. Happens to all of them eventually.

rear suspension 5 link had some arms wear, caused the "standing in a canoe" handling. not expensive to RR (mine was the upper front arms needing replacement, the rest are more difficult). accel hard and if it does the sine wave on shifts, take a closer look.

ACC can be flaky, mine stays on all the time and runs AC all the time but Im in Atlanta so thats a good thing.

Cruise - you can get the amp for $150 rebuilt, not a deal breaker.

engine - water pump, alt, aux pump, oil level sender, oil press sender, rad hoses, serp belt tensioner/spring - all of this is easy and cheap. starter went up at 270k, a real chore to RR but not too expensive. diesel heater t-stat - not hard but over $100 for that silly plastic part. glows twice in 60k, not that easy and be sure the metal fuel lines arent butchered because if bent will break. The metal injector lines are very hard to find, last I check MB was on an 8 month back order.

otherwise engine/trans are good but drip a little.

its a VERY VERY well built car, needs a bit more mtc than 123 but IMO well worth it. I think you will be satisfied, make sure to run carfax and get the title, ect... ect...

You most likely WONT find engine parts in the bone yard like a 617 but will find lots of interior goodies.

617 is still most reliable, cheap diesel they made and you will spend more on 603. But the refinements are well worth the hassles if you arent afraid to get your hands dirty.

There do seem to be some quirks. When I got the car, there were two sets of keys. I got it started with the well worn one after picking up the car from the pre-purchase inspection. It needed fuel, so I stopped at a gas station, added a couple of gallons, and tried to leave. The key would turn, but there wasn't any response. No lights, nothing. I don't think it would even glow.

I popped the hood, checked the battery leads (brand new, beefy battery). Looks fine. Still couldn't get it to respond. So I push it out of the way and a friendly passer-by offers to lend a hand with a jump. I figure it couldn't hurt. We get it hooked up, and then I decide to try the other set of keys I got (that the shop had - a set of brand new master and valet keys). Glowed, fired right up.

I've only used the new keys since, and I haven't had a problem firing it right up. Is this something I should be worried about? It doesn't look like I need to replace the ignition cylinder yet...but, if it might go out slightly down the road, I can replace it. From what I've looked at, it looks to be about the same difficulty as when I did my 240D (cake).

Other quirks include the drivers door not being able to unlock the car. It just doesn't turn. It locks the car just fine. I don't see this as an immediate problem, as the central locking system works well, and I can use either the passenger door, or trunk. Would this just need a new lock cylinder as well? I'd imagine that the door would need some pretty heavy disassembly, however, that's probably not bad, either.

The shop that did the PPI said there was a slight (very) fuel leak, and I believe the service adviser said it was probably at the injectors. They said it was nothing to be worried about, and it didn't need any attention. All of the other fluid levels were fine, if it burns any oil, it's probably not noticeable.

The car seems to run at about 95C here, in 90-95F weather, after the turbo has kicked in for an extended period (I've never driven a car with a turbo charger before, so the throttle response is still new to me). I'm going out to check on the aux fan right now.

The ACC seems to work as designed. All of the buttons re-direct the air, recirculate, turn air off seem to operate the pods as they should. The AC works, maybe not as well as I'd like, but the ambient temperatures are a little high (95F, and humid). I might think about using minor tint to keep the temperatures down a little more. The maroon interior has a way of making things warm.

It's got a #14 head, doesn't use coolant, and no 'cold pressure' symptoms whatsoever. I'm going to be really cautious with keeping the cooling system well maintained. I don't want to be paranoid, just careful.

When I finish grad school (very soon), and find a job, I'll have plenty of weekend time to R&R parts, and the money will be more plentiful :)

Are there any red-flags stopping me from driving 200 (highway) miles? I need to go back to Maryland and fly to defend my Masters in less than a week. I can always take the train, if needed. The previous owner had been using the vehicle as a commuter car (probably 30-40 miles a day) for a long time without any trouble.

Thanks for any input :)

I think I'm going to have to come up with a name for her soon. :cool:

Ok, I think I answered my own question.

I got stuck in a parking lot. Same starting issues as before. It is really odd, I'm not sure if it is an electrical gremlin or what.

The first try, it glowed, and then clicked (sounded like a relay, single click) when I went to start it. Subsequent tries (after making sure it was in park, and taking the key out and putting it back in), led to less results. It would light up in key position 1, but when I got to the glow position, the lights all disappear...more or less unresponsive. The weird thing is the response of the cd player. It wasn't on when I turned off the car, nor is it on when I try to start it, but it acts like it tries to do something (read a cd maybe) when / after my attempts of starting (but, it's fully off).

That's what's leading me to suspect some sort of electrical problem. I'm definitely taking the train to MD, and when I do get back, I'll have a multimeter and a battery charger on hand, as well as some free time. I'll start a new thread when I get to that point just related to this problem.

Oh, today, the car didn't hit 90C (probably 87-88 when it warmed up, without AC), I guess I was a little rough on the accelerator before (and I had the AC on).

Thanks for reading.

Sounds like a classic weak-connection to the battery symptom. If the dome-light stays bright while the ignition is dead however, more likely ignition switch or neutral-safety switch (try starting in neutral or hold the key in start position and shift around).

A great car for your trip if you sort out the starting issue. Also, you can bypass the starter switch circuit with the connector on the inner-firewall just ahead of the brake booster.

Fuel leak might be the rubber/cloth fuel return lines, typical. Replace with good fuel line from Mercedes (there is a kit, click the parts button above).

The door locks are a cinch to remove. There is a plug in the doorjamb, behind which is a set-screw that holds the door lock portion of the handle in place. The larger plug in the doorjamb is to un-plug the electrical portion of that same lock.

well if it lites off on a jumper then the battery is either flat out dead or just isnt getting charged. the alt's on those things are really weak 65 amp units (but oddly, the cores are in high demand for some reason). once you get it running check battery voltage, make sure its over 14v idle, then turn on all the acces, it shouldnt really go lower than 13.5 or so. if it does, suspect alt. You can replace it w/120 amp unit from a later 124 (or even 140, 150 amp units from 98-99 E300) they all fit (but you need to swap over your pulley on the 140/150 amp units). I just used the 120 amp bosch, cheaper than 65 amp! You need to grab the wire harness from alt to battery though unless you feel like making your own. Call the Benz Store in Atlanta, Ken will send you everything needed. He hooked me up!

I had it not start twice while being jumped, and the battery ($143 interstate) and alternator are brand new. I'm leaning toward it being an electrical issue. I'll probably change out the battery wires and make sure that they're making very good connections. The odd thing is, the problems usually happen when the car is warmed up. If it has been sitting, fires right up. I think the previous owner had the same problem, and just didn't mention it. The maintenance documents seem to point that way (hard starting -> got new glow plugs, alternator, battery, etc).

I'm waist deep in thesis work, so, I'll post back late next week. :)

New doesn't mean good in alternators, and I'd still suspect the wiring.

Paul: Who wants these 65a alternators? I have two or three I pulled from my cars when upgrading, ... you mean someone will PAY me for them?

Also check the wires on the starter to make sure they are tight.

I have no idea, but thats what Ken at benz store told me when I bought the 120 amp from him. he said the 120's were dime/dozen and he didnt even care about cores for that 1 but the 65 amp core was worth something...go figure...

hey connect a jumper from + lead to starter motor when it wont crank, to see if it is faulty 4 ga wire from bat to starter. careful, connect starter end 1st!!

Hmm. I have a 65 A just sitting around as well.

One thing sort of mentioned is the neutral safety switch. Did you try starting it up in neutral? One thing that fails in these is a little rubber bushing on the shifter connection. When I got my wagon I had intermittent starts and the guy I bought it from told me I would need a neutral safety switch. All I really needed was the shift bushing, which is about a buck and not very hard to replace. If the bushing gets really worn you can have trouble starting in neutral as well.

You have presumably read gsxr's buying guide. There are some important things like the vacuum pump to check right away. If you had the compression tested during the inspection and cylinder 1 was off you probably have a blown head gasket at the famous oil passage -- it may not manifest in typical ways. Mine didn't. Probably a good idea to replace the coolant and thermostat unless you know the coolant is mercedes approved. Doesn't cost much and is probably a good idea.

Like a2t I had to replace the d*mn ignition tumbler a few months ago. It is really easy to do if it isn't broken. It is a huge PITA if you have a key stuck in there. You don't always get much warning as I found out.

There are plenty of easy little upgrades to do, some of which, like changing the fan/fan clutch and adding afterglow can improve how the car runs.

Have fun.

Hey guys,

Just a little update and some pictures. Everything has been pretty smooth running since the temperature drop. I think there might be a glow plug out, I'll have to check it whenever my multimeter gets here (c'mon fluke, I bought it a while ago!). Haven't had any issues with starting, but I'll still look over the cables and connections (and keep track of resistances when doing so), just to see if anything makes a difference.

Hmm...vacuum pump...how would I go about checking that? I've seen a few horror stories about that.

I'd love to get some of these moderate repairs done in the future, however, I'm still hunting for a job at the moment, so, only the critical ones are getting attention. Hmm, afterglow does sound nice. :cool:

Now, some pictures for your viewing pleasure. I just washed, ran a clay bar over all the paint, and waxed (Meguiars Gold Class). Enjoy!
http://memimage.cardomain.com/ride_i...0011_large.jpg
http://memimage.cardomain.com/ride_i...0009_large.jpg

The rest are on the cardomain page here. I even put my list of future repairs (page 4). :D

PS. Anyone got any tips for cleaning the original wheels? I can keep scrubbing them with a brush, but I don't want to damage them (I'm not sure what kind of finish they've got)

The wheels are painted silver. Clean is difficult in the holes, best of luck. Most likely by now the brake dust has made a permanant home there and the only way to clean it up is to paint.

The 15-hole wheels look brilliant when freshly painted, when the holes show silver inside, well worth it but they're difficult to keep that way.

Wheels, etc.
 

The wheels are painted. They will never look beautiful; they didn't look beautiful when new. Best for now to leave them as-is. Don't get "dust shields" as they are said to block air from properly cooling the brakes. In the future, consider the chrome version of the same wheel, which you can find for sale here and there (some think chrome looks tacky, YMMV). There are also later-model wheels that are similar but have fewer holes (less to clean). They should fit your car -- I don't know the details.

Inspect the vacuum pump by looking at it. If it has four screws on the front surface, it's a new one with the sealed bearing, you're OK. If it has a smooth sheet-metal front with no screws, it's the original, think about getting a new one. About $300, you can do the job yourself, lots of threads on that subject here, make sure the new pump comes with the correct gasket or it won't fit, search this forum for pictures and instructions.

Euro headlights are nice (I think the wipers look silly) but expensive, about $600 the pair, maybe more. You have to get (and paint -- they come in primer only) new trim panels for below the headlights, ones without the wiper hole. There are also wipers for the Euro headlights, even more $$$. Here is my '87 w/Euro headlights. I put X-pel protective plastic film on both the headlights and the lower trim panel, it does a good job of preventing rock chips.


http://i323.photobucket.com/albums/n...D/IMG_2266.jpg


Jeremy

There's an occassional old bearing vacuum pump with a new style cover. There should be a plate over each end of the bearing completely blocking view of the balls in the races.

Euro style headlight wipers are available used from 94-95 124s.

Sixto
87 300D

Well, my suspicion has been confirmed. I'll probably replace the vacuum pump soon. It looks like it might be original. It's a little hard to see in the picture, right under the s-belt is a star. What is the consensus about quality of vacuum pumps? I'm probably going to want to replace it and never have to worry about it again. Any difference between OE or OEM (or does Pierburg make them all and I should just go with whichever is cheaper)? Are the differences in gaskets something you can discern while purchasing, or will I notice it when I have the pumps side by side and have to make a decision then?

I managed to give the wheels a good scrubbing with a small nylon brush, but some of the brake dust is pretty well stuck on. Guess that'll have to do for now :D

So many questions! Thanks for your patience, guys. It's really appreciated. :)

Looks like the original VP.

Nice car; looks just like mine!

same VP in my 87 300D. 305k miles on it. guess i should think about changing it?

That is the common wisdom here.

Here's what I've found on the vacuum pump:

OM603: Vacuum pump explosion, bearing intact! Injection Pump Timing device wrecked
Look what came out of my oil pan today (bearings)
How to replace a 603 vacuum pump. (SDL)
"New style" OM603 vacuum pumps may not be "safe" (pictures of vacuum pumps, shows visible differences)
vacuum pump in OM603 (recommended life on vacuum pump)

After seeing what could happen, I'll sleep better knowing my pump is new :cool:

Early engines require the dam gasket, the rest can use the outline gasket. IIRC non-MB label Pierbergs come with the dam gasket which should be fine for any engine. The instructions with non-MB label Pierbergs say to ditch the basket behind the vacuum pump. You have to ditch the basket when installing the dam gasket. You can keep the basket with the outline gasket. Say that three times quickly.

http://www.w124performance.com/image...mp_gaskets.jpg

Sixto
87 300D

how common is this failure on 603s?