Mercedes 300D Suggestions

elrod1

ha ha ha....yeah i know about the little thingy. i suppose replacing the fuse can't hurt regardless. thanks for the advice guys, i'm looking forward to having her running healthy again. oh i've had the fuse panel off a few times and it's a real pain to get it back on as far as manuevering it amongst everything else...have any of you perfected a technique to make it easy?

wvoplush2

Well, just thought id share a bit of potential advice regarding the leaky valve cover. An experienced german mechanic said that if my valve cover is warped, a trick he uses is that once you have the VC off, you turn it upside down, and file down the round casting areas slightly where the 4 bolts mount the VC to the head. he said normally u cant tighten it any extra, because those castings prevent any further tightening by bottoming out. by filing them down, u can put extra pressure on the gasket--hopefully enough to make up for slight warpage and consequently prevent further leaks. he says shifty is right, dont use sealant. well, if anyone has experience or opinions, id like to know. otherwise, tomorrow the job will be done. I guess the worst that could happen is that ill have to buy a new VC.
i still dont have a good solution for the leaking bolt on top. maybe the only thing to try is a very small amount of sealant there--or make a rubber washer??? the mech said he hadnt seen that, and try this maybe.

one question if anyone knows---How do u access the speedo cable to lube it?? my disk manual doesnt address this---anyone know??? i plan on using "kable eaze"....

Mr_Shiftright

I think your instrument panel just pries out. Your mechanic should know.

brightbus

been a while since ive posted, but i have a 76 300d. just wanted to know where to check to get the master lock system working again (hasnt worked since ive had the car) but i havent had others problems associated with vacuum leakage (engine not shutting off etc) so i dont know where to start. any suggestions?

fintail

Not a diesel question...but are Mercedes batteries superior to others? The (aftermarket) battery on the fintail is about 5 years old now, and on cool mornings cranks slow. I was talking to my mechanic, and he said a MB unit is the best bet, even though they cost about twice as much. Is this true?

burdawg

In my opinion, no. Any good name brand heavy duty battery of the correct size should be sufficient.

countsmackula1

Anyone know if it's OK to run "farm" /off-road"diesel in these things? It's about 30 some cents cheaper. $2.41 here in VA versus $2.78 for 500ppm diesel. Not all our stations here have the new 15 ppm diesle yet.It is priced about the same. I know it's probably illegal, but will it work mechanically? It would have better lubrication properties( removal of sulfur naturally reduces lubricity), so will it clog up anything? Thanks in advance! --the count

brightbus

as far as i know its illegal, and the reason its cheaper because it doesnt have the "road tax." is actually died a different color, so if you got pulled over and had that in your tank, you could face a serious fine. and as far as i know yes mechanically it would work in any diesel

in other things, anyone gonna respond to my vacuum question?

fintail

I thought it sounded odd. The battery in it now is a "truck" batter per the label on the battery. The old beast takes a large battery, which always amused me in comparing it to the small one in my 126.

This is the only vintage MB thread, so I'll gripe about the fintail here. It's been in for some work...so far, one of the spark plug wires I bought was defective, the generator bracket that was supposed to fit the car doesn't fit, and the clatter I've noticed that I thought was from a wheel bearing or misadjusted brake is apparently some kind of driveline bearing, not easy to fix. The fun of old cars. The one week trip to the shop is at 3, and counting.

burdawg

A diesel engine , because of the high compression ratio, needs a large battery to turn it over reliably when starting.

Mr_Shiftright

You got THAT right...and in winter weather a really HUGE battery would be in order. When I worked in Alaska, sometimes they wouldn't shut the big diesel trucks off at all. They just ran from November through March and idled all night. If they were traveling, they'd shut them off for quick rest stops and service, of course. Most had ether injection operated from the dashboard, as I recall.

fintail

My car is a gas, FWIW. It still takes a huge battery though, and the factory battery frame is bigger yet.

burdawg

I also should mention that the glowplugs can use quite a bit of current in cold weather (well, sometimes any weather) when warming them up to start.

ryan66

I have 1982 MB 300D turbo. Trans sometimes slipped ( going
into 3rd ) for a year. I could live with that. Now I must drive slow for about 4 miles before it will even try to shift. Had filter changed, no help. Would like to check modulator, need help finding it. Thought someone went through this mess and had some tips. THANKS

raybona

Ryan,
I just got through changing out my modulator on my 300d, and I can tell you it's kind of a pain in the neck unless you have a lift. Nonetheless, it is located on the driver's side of the transmission and has a vacuum hose running to it. You should test your vacuum system including the modulator before taking it out. Your problem could be a simple vacuum problem or much worse. Use Google, there are lots of internet pages on this topic. If the vacuum test seems daunting you should seek out a good mechanic who is familiar with mercedes to help you.

rustics

Been reading past messages for the last 3 weeks and learned lots. Planning on buying a good late 80's 300D if I can find one. Does anyone have experience running these engines in cold climates? Assuming a decent running engine with <200-250k miles, good battery etc, will it start at 5 pm after standing around all day at -20C/0F? That is the coldest usually expected where I am. I ran a VW diesel for years, it would start OK as long as the battery and glow plugs were good, but any weaknesses in those areas and....no start. I would expect the MB to be similar. Haven't seen many messages about this topic. Any comments or experiences welcomed, thanks!

Mr_Shiftright

At zero F, I think you'll need all the help you can get. Yep, strong battery is good, new glow plugs are good...but you'd better count on a)synthetic oil, b)an anti-gel fuel additive used regularly and c) if it's practical, an engine heater. But at least A and B, because you have no slack otherwise for cold starts. My experience is that 300Ds are not good starters below 20 degrees....and if you go below 0 you may even need to resort to the extreme of adding a small amount of gasoline to your diesel fuel---if all these other measures don't work. It worked for the Russians in World War II, and it could work for you! You'll have to look up the recommended gasoline/diesel fuel ratio, I just don't recall...probably no more than 20%.

rustics

Thanks. More or less as I expected. I'm in NB, eastern Canada, and most people have block heaters on their cars for winter use. An hour or so was usually enough to allow my VW diesel to start right up, but the problem comes at the end of a working day on those frigid days in late January... and then you want to get in quick ...start up...and drive home!! A no-start then is miserable. Sometimes a shot of ether-based quick-start into the air intake will do the trick, but if this doesn't work first time you're usually out of luck. This again is experience with my VW. A battery heater also helps when it's really cold. Still cogitating on a MB diesel...

Aren't most diesel "additives" mostly ethanol/methanol? Adding gasoline might lower the viscosity a bit, but winter diesel here is already formulated for the cold weather.

Cheers.

Mr_Shiftright

Ether is okay but you have to be judicious in its use, as it is a highly effective solvent as well as very explosive. So really, pouring tons of it into an engine using 21:1 compression really doesn't sound like a good idea. One or two squirts.

When I worked in Alaska, the diesel trucks there solved the problem of sub-zero starting. They just never shut the engines off from November through March. They idled all night at the roadhouses.

nrkmann

Mr Shiftright is correct, about 20% gas, synthetic oil, and don't get in a hurry to start you car.

I did this for a company of military vehicles in Korea when it was -20 without windchill and -40 with the windchill calculated.

Let the glow plugs go about 30-40 seconds past the glow plug light going out and then start. There is a timer in the circuit that turns the plugs off after about 45 seconds after the light goes out. Try it you will hear a click as the relay turns the plugs off.

Best to use an engine/oil heater, MB has one built in and you should try to wire it and test it in the good weather.

As the battery gets cold it is weaker. Use a trickle charger at home and it will help to keep the battery warm. Another item is a battery hot blanket that you can plug in with the engine/oil heater.

NRK

rustics

Tks NRK. Interesting. Yes, here too sometimes heavy diesels are idled all winter, e.g. rail engines. Not a very economical or sustainable practice and not one I'd like to adopt with any car of mine!

On my VW diesel I used a battery blanket and block heater, most of the time not absolutely necessary, except on the coldest days. Those are the real tests of how good a diesel is. Interesting that MB has a built-in heater! I had never heard of that.

I am looking at a 76 300d , not winter driven, 165k miles, everything working, recent engine/trans service, brakes done, little or no rust. Any estimates on what would be a reasonable price?

cheers.

Mr_Shiftright

$1,200 or so. If it looked like it came out of the box, maybe $2,000.

bcparsons

I have another situation now and that is that I changed the fuel filters today and crushed the seal on the pump shaft when I bled the air out of the fuel line.
Obviously I haven't called the shop but what is the fix for this problem?

Many thanks

Mr_Shiftright

Not sure what you are referring to...you mean the line coming out of the injection pump?

ryan77300d

Hi, I recently bought a 1977 Mercedes 300D for my first car last week, and I must say up to this point I am not impressed at the least. I researched 300D's through this site and others, and really liked the concept of the car, and the fact it had an inline 5cyl diesel. Everything is decent on this car, except for the fact that a day after I brought it home, it started to leak anti-freeze. This car is only tolerable when it's in perfect working order, but not at all when it's spewing out green liquid all over the garage floor. It leaks out from, what I can see, the seal where the water pump is. I'm certain it isn't comming from the over-flow tube, as I checked that obvious spot first. There's anti-freeze all over everything, from the alternator to the steering arms, to the front right brake drum, yet it only leaks about 1/2 cup of anti-freeze when stopped. There are no leaks when it's driving, only when it's idling in Park, or at a stoplight. It leaks more when it's just sitting in Park idling though. I hope that makes the least bit of sense. I am new to these cars, any car for that matter, as it's my first, but I'm very mechanically able and am curious as to why my hard earned money, while not much, has gone towards a :lemon: . Many thanks. -Ryan

PS- The last thing I want to hear is that I have a cracked block. According to the dealership, the car has never been winter driven, (I'm in Ontario) and has 113,000miles.

burdawg

Check to see if the upper radiator hose is dripping on the bottom. It could be running down around the water pump. It's possible that since it only happens when your idling the coolant temperature could be going up (normal) and causing a loose or worn hose to leak at the thermostat elbow.

Mr_Shiftright

Certainly could be the water pump. That's not too big a deal. After all, this is a 30 year old car, and mythology aside, it's going to show normal wear just like any car with 113,000 miles. That's more than enough miles to wear out a water pump. Best thing is get it on a lift and see what's what.

burdawg

Could be. My experience though is that if your water pump is leaking it leaks all the time.

Mr_Shiftright

not always...if it's spinning fast enough it will hurl the water through the outlet rather than the weep hole in the shaft bushing.

ryan77300d

Thanks Shiftright and burdawg, I suspected the same. Upon closer inspection, it is infact the bottom of the water pump seal, where the leak is. This morning the car totally blew out the entire contents of the rad through that leaky seal, so I'll just have to wait for the gasket to come in on Monday. Thanks again, -Ryan

bcparsons

I was refering to the primer pump, which bleeds the air out of the fuel lines and filters after changing them. After more discussions with others I just bought a replacement pump which has been upgraded and will instrall that.

Thanks though for your reply.

Mr_Shiftright

Okay the little pump...got it...most of them don't work on those old cars anyway, so you probably did what was necessary in any event.

bcparsons

I have a new primer pump and it takes a 17mm wrench to install. The old original pump takes something larger than a 19mm which I don't have and my micrometer is in inches so I am not really sure what size wrench I need. Plus the fact that the part is in a really restrictive space and I'm figuring that I will have to cut the wrench down a bit to make it work.Do you know is what the correct size wrench?
I may just use (ugh!!!)a vise grip.

Mr_Shiftright

11/16 is the rough equivalent of 19 mm

5/8 is the rough equivalent of 17 mm

burdawg

A crescent wrench (or adjustable wrench) would be a better choice if the correct metric size isn't available.

bcparsons

OK OK OK! I got it off using a 15/16 wrench that I cut down to about 6 inches and with a little pressure it came right off. I've been taking some breaks since it's about 95/95 heat and humidity here and spent the time cooling off bugging you guys. Thanks for all your answers and help. Now I just have to go back to the dealer and get the right part,the one they sold me does not fit.At the very least I can replace the o-ring which is where the leak is anyway.
Thanks again.

rustics

Hi all, another cold weather question. I read a lot about malfunctioning "climate control" in the MB in this forum. Where I am, A/c is nice, but a person can survive without it. Nice about 30 days per year. Heat is another matter. A Must Have. More than 100 days/year. Are the MB diesel model heaters up to snuff for significant cold (below 10F/-12C?). When the climate control is not working properly, is this usually due to electronic controls, sensors, failure of blower fan, or something else? In other words, what usually goes, and how easy is it to fix? Thanks!

Mr_Shiftright

The heat is fine when it's working, and yeah, usually it is an electronic fault. The entire climate control is absurdly complex, which is typically German. The usual joke is that a German directional signal has 147 parts,is made of titanium, works most of the time and costs $500 to fix; a Japanese one has 17 parts, is made of high quality weighted and shaped plastic, works all the time, and costs $50 to fix.

There are *different systems* on 80s cars and some are worse than others, but all are pretty lame. Sooner or later, you or any 80s Mercedes owner will have to deal with it. The Mercedes AC sucks altogether, but I did manage to keep my working rather well, although I had to charge it and fix leaks at least once a year to get any kind of efficiency out of it. But I ran AC in the desert for hundreds of miles, no problem---it cost me about $250 a year to keep AC working.

Your results may vary, and I hope so! I personally never had a heater problem per se but the climate control was always lazy and erratic.

Sometimes if you spin the climate control dial and count to 100, it'll work. Be patient, cross your fingers, pray and buy a rabbit's foot.

wvoplush2

Thanks in advance to Mr. S and all others who keep this going....

I've been away from a computer for a few weeks, but thought Id share some results and post another question. Hope you dont mind my encyclopedic rambling....

Ive been on a big road trip with my 82 3ooD. a few weeks ago my speedo hit 200k and 2 miles later started malfunctioning--it began clicking like a metronome. of course i followed some good advice and removed the instrument panel to see what was going on. i was able to use a small square drive to attempt to reverse the speedo where the cable inserts, but found that it would only reverse the trip meter. in desperation to avoid the annoying clicking, i tried to reverse the miles from the front of the odometer by using a tiny screwdriver, which actually worked without breaking anything. i had to start from the right and work my way left thru the tiny gears, but once i tested it, it stopped the click, and joyfully I removed many long miles, and added new life to my engine and tranny!!! just a little bit of magic for anyone plagued by the clicking speedo. Note: I see that this had been done before, as when i registered the car it "had" 195K, but the woman at DMV said it had a reported 196K.

Another note on my valve cover gasket-- I took more good advice from a mechanic and filed down the castings on the V-C where the V-C bolts mount to put pressure on the gasket--about 10 thousandths. i also checked for warpage with a straight-edge. ignoring some advice, i used copper spray adhesive to "glue" or seal the gasket to the V-C, as this didnt leave any gloppy silicone to clog oil ports and nicely kept the gasket in position during installation. Long story short--it worked, no leaks after 500 miles.

Now to my question:

Yesterday my alternator stopped charging. I started up in the morning ok, but after shutting it off and restarting, it cranked at half speed. it started and the next time was even lower. 3rd time wouldnt start. from previous posts i suspected the voltage regulator on the alternator went bad, if not the whole alt. i bought a new VR, but not installed. what baffles me is that today in the 90 degree weather the temp guage for the first time ever went above 60 C (its been off and on 90 for a month). It happened several times while idling in traffic, but if i put it in neutral and revved it up, the temp guage went down. it never went above 80 C and never boiled coolant that i could see. once i started driving, no temp increase. How are these two problems related? I could see that if it was an electric fan, then the low battery/ bad volt. reg would cause a fan malfunction, but its a belt drive clutch fan. Any ideas?? thermostat??

Sorry for the long post, but hope its useful. Thanks again and i still love my car. :shades:

rustics

Thanks for the useful info.
On the same logic I guess French-built indicator signal would be made of one part, out of rolled sheet tin, look ridiculous and sort of -loosely- work, when it didn't fall off, but be unfixable when broken. I'm thinking of the gear shift on a 2CV, for example. Well I hope my MB will have strong heat, and weak a/c is OK! Thanks again.

Mr_Shiftright

I think you'll be fine. At worst, the climate control usually gets "lazy" and takes time to work. Just keep punching buttons like I did and 99% of the time you'll get your heat.

The AC is, well---it is what it is and ain't what it ain't. The Germans just couldn't design efficient AC for the longest time. Between their temperate climate and the large glass areas of their cars and some of their whacky engineering solutions, the poor AC just lagged far behind American units.

ryan77300d

I posted a mesage a while ago about my '77 300D leaking anti-freeze out of the water pump seal. Does anyone have a clue as to how to go about removing the water pump? This is, in it's entirety, a crazy task. Not only did the fan and pully have to come out, so did 5-6 bolts that hold the water pump to the engine. THEN, there's still two bolts holding the pump in there, and, of course, one is behind a huge steel contraption, that holds the A/C compressor, A/C pulley, and idler pully on to the front of the engine. THEN there's the second bolt, which is conveniently located 1/4 inch behind the crank shaft dampener and related engine pulleys. Just close enough to it that there is no hope of losening the bolt and backing it out all the way. Classic German Engineering. I'm ready to spend $300 to get this car towed to a garage to finish what I've started, even though it's all for a seal that cost me $1.75. Has anyone removed a water pump from a 300D? Any sort of guidance would be greatly appreciated, especially when the local M-B dealership wants $195.00 for a shop manual that's on 3 CD's.

-Ryan

burdawg

Your not running into anything new. It's quite common to have to take a good bit off the front of the engine to change the water pump. Most likely you'll have to take the A/C compressor loose from the bracket and set it aside (don't disconnnect the hoses). You may have to remove the damper and pully also.
I hope you made sure the water pump isn't leaking from the shaft seal, and just running off the bottom of the pump, causing you to think just the pump gasket is leaking.
I usually take the radiator out for access. It's a good time to have the radiator cleaned (rodded out) and checked also.
It's not anything to do with German engineering. That engineering is not to make it easier to service and repair, but to make it run and operate smoothly.

ryan77300d

Excellent. I think I'm just going to buy a new water pump and get someone to install it, and then add $500 to my selling price of this beater when the time comes. If I owned a shop or garage, sure I would care enough to do everything myself, and do it right. But I have half a suburban garage and a few tools, never mind the patience to put that work into a car with this amount of mediocre performance and handling. Thanks for the reply, as I re-read my previous post and it seemed biter, just frustration, I can assure you.

-Ryan

brakeengr

Yesterday I started having trouble turning the ignition key. It goes in OK, but does not turn. I made sure the steering isn't "locked" or stuck. After a lot of juggling, it did turn- then starts up fine. Today again the key didn't want to turn.
Anybody run into this problem? Is it OK/ safe/ helpful to spray WD40 in the ignition?- Thanks-

Mr_Shiftright

NOOOOOOOOOO! No WD-40!!!!!

Use graphite lock lubricant please.

lemmer

Why not WD-40? It is almost as useful as duct tape for fixing stuff, especially cars.

brakeengr

Thanks for the graphite lock lubricant suggestion.
What form does it come in? Powder/ paste? And how do I apply it and where can I get it from? Autozone/ Murray kinda places?

Mr_Shiftright

It's available either as a spray. I prefer the powdered form in a kind of squeeze tube, like toothpaste.

WD-40, or any lube for that matter, isn't good for locks. It's an oil-base and it gets old and gums everything up. You'll may get results but then later on bad results. Graphite just stays the same regardless of how long it sits in there.

oregonboy

Graphite just stays the same regardless of how long it sits in there.

... until someone gives it a squirt of WD-40 and turns the graphite powder into graphite paste.

james