Mercedes 300D Suggestions

benjamin2

captron

This looks like a great site. Just wondering, on cold starts, my 300D turbo will turn over, but won't stay running unless I give it some diesel for about 20-30 sec. I poured some fuel injector cleaner for diesels in the fuel tank, which helped performance a bit only. Occasionally, I get some white smoke coming out of the exhaust pipe, too. Pretty random, though. Glow plugs need changing? Thanks!

Mr_Shiftright

Glow plugs definitely if you haven't in the last 2-3 years. Also change all your filters.

captron

will do. thanks! I heard there are two fuel filters, one by the gas tank and one up front. True? Any place I can get a repair manual? Thanks again. Definitely using this website!

Mr_Shiftright

The filters are the little white one right by the injection pump and the large cannister type filter on the left front of the engine. Best repair manual is from the dealer, not cheap but really there is nothing like it. I recommend buying all your filters either from the dealer (just a few bucks more) or from a specialist who knows MB diesels.

Also these engine need a valve adjustment every 30,000 miles or so.

captron

thank you! Will do. it's got 238K on it, so I should just overhaul it. Too good to sell, though. take care, Mr Shiftright!

Mr_Shiftright

Well if you take good care of that engine, no reason why it shouldn't run efficiently up to 275K or so....after that they get pretty tired, although they might stagger along. Usual tip-off is oil consumption and lots of puking (sorry) of oil over the engine from blow-by, and severe contamination of the air filter.

mb300d

I have an ongoing problem with my car E300D, been with my mechanic almost every month can't seem to trouble shoot the problem, the car is hesitating on 50-70 miles and spewing really black smokes when you stepped on the gas pedal. He tried to clean the intake manifold but it's still doing the same problem. I have 229K miles on the car and still running strong just this problem.

Anyone can help?

bznupe14

How did you repair the vacuum problem? I am having the same problem.

cody2105

I have a 1987 300TD inline-6 which i just installed another motor,everything is fine except I cant start the car with the key but i can shut it off with the key once i jump start it at the starter motor.Someone suggested that i check the Neutral Safety Switch. Where is the neutral safety switch located?any idea/suggestion? please help.

tim21

Mr Shiftright - My son pulled the knob off the pass. side doorlock on my 1979 300D. It is stuck in locked position - I'm not very handy - should I attempt this or take it to the shop.

Mr_Shiftright

First thing I'd try is to buy a new knob and then try to "catch" the rod that it screws onto by fishing around in the hole with a small flashlight. If you can get the new knob over the rod, you can screw the new knob onto the rod and then pull it up!.

Also, you might be able to tease it up with longnose pliers. If you want to pop the door panel off that isn't too hard. You take out the armrest screws (two long phillips heads), then pry out the black backing behind the door opener, then remove the screw that holds the chrome backing plate behind the door opener, then remove the small chrome piece for the door striker (on the edge of the door, up high). Then you get a ruler or putty knife and pry along the door panel, popping the clips. Once you have them all, you lift UP and the door panel comes off. You'll see the little rod with the missing knob and you can push it upwards and screw on a new knob.

Mr_Shiftright

Sounds like an injector with a bad spray pattern....try some BGK 44 injector cleaner in the tank and of course, my old manta, change your fuel filters. You might also add a "biocide" to the tank to see if you have some gunk growing in there. Oddly enough, algae likes diesel fuel.

Mr_Shiftright

I think the safety switch is under the PRNDL facia, inside the console. You have to take the console out I believe but I'm not sure quite how to access it or whether you can reach it from underneath the car. It's been too long, I forget, sorry. But yeah, the neutral safety switch is a good guess if you can crank the engine by hot-wiring the starter solenoid itself. This means that current to the ignition switch is being interrupted either by the NSS or by a bad ignition lock.

mb300d

Thanks a lot, I will asked the mechanic to check on this. He mentioned about the
intake manifold and throttle. Is this part of the fuel injector? Sorry for my ignorance, I am not educated to learn this things, maybe I need to find a new mechanic.

Mr_Shiftright

Well maybe he knows a lot, I don't have the car in front of me, but the throttle idea doesn't sounds so good---maybe he means making adjustments to the throttle rod as it manipulates the injection pump.....I dunno what he's thinking exactly.

People think diesels are "simple" engines but they really aren't--it's just a different kind of knowledge.

mb300d

Mr. shiftright, I did some researched and found out about BG44K is for gasoline only and BG244 is for diesel. I will get the Fuel Injection service recommended by BG Products who manufactured these additives. Thanks again!

Mr_Shiftright

Oh great, sorry if I was a bit sloppy on that...it's been a while and I've forgotten the details on the product. All I can tell you is that I had rough idling, stalling and black smoke, ALL DAY LONG...I went to the guys who now work on my porsche and who are expert engine builders---they handed me some BGK and told me to hit the freeway...within 15 minutes the car was purring. The skeptic was converted on the spot, because this was a persistent problem. Obviously, it cleaned out one injector or improved its spray pattern.

dpotter1

My diseal engine is very load inside the cab and out side any suggestions on quieting it down. Also it vibrates when it idles. any suggestions.

dpotter1

Ive heard of people mixing there diseal with vegtable oil. is there such a thing if so how does it preform and do i need special filters. also what is the ratio of gas to oil.

Mr_Shiftright

If it's real loud this may be a function of injection pump timing. You need to go to a diesel specialist to have this set up properly.

You can also make sure you have your hood insulation in place, and I also added dyna-mat soundproofing against the firewall from inside the car (under the carpeting).

But injection pump timing and a valve adjustment may do wonders for you.

Also, one last thing, you can try a "cetane enhancer" which is like an octane enchancer, but for diesel fuel.

dpotter1

I checked the instalation and it is almost all gone. what should i put in its place

dpotter1

I can feel the springs in my seats . and one is sliced up. any suggestions on were to buy new ones

Mr_Shiftright

do a google search for Mercedes parts and see what comes up. I think various independent suppliers provide cut-to-fit material. Heck you may still be able to buy it from the dealer. But don't expect dramatic improvement....but you will notice less noise.

Mr_Shiftright

Usually the springs just break. What you need to do is have an upholstery shop repair the springs (wire them together again) and then re-pad and shape the bottom of the seat. Basically you have to rebuild your seat as best you can. Figure a couple hundred dollars.

ryan66

I recently got a '82 300D. Tach worked correctly twice. Needle keeps bouncing
around. Any ideas???
Also, engine keeps running after turning key off. Can get it to stop right away
by pushing "stop" on linkage. Can't find the solenoid that the Hayes book says
is the fix. Anyone know what to do?

Mr_Shiftright

You might just have a vacuum leak somewhere. ANY vacuum leak will cause this to happen as the shut off valve works off vacuum. What do you mean pushing "stop"? You mean forcing the linkage shut? There's an actual little lever in the engine compartment for this problem at the back of the linkage near the firewall.

ryan66

Just bought the car. Was told there was a vacuum leak that kept locks from working. Wonder if it's the same leak.
On the linkage in engine compartment is a red "stop", I can push it and engine
stops. I thought the shut off solenoid would completely close the throttle. Can
not find one on my car.

Mr_Shiftright

Yep I think the vacuum leak (wherever it is) is causing all your problems. The shut off valve needs vacuum to shut off the fuel to your engine (as you have no ignition system to turn off)....so no vacuum, no shut off.

300cdveggie

Magically last week all four power windows stopped working in our '84 300CD.

I've checked the fuses and they are intact. There is power on both sides of the fuse block. The motors and switches work because I was able to supply power to the switches with a wire from the battery and they went up.

Is there a relay or another fuse between the fuse block and the windows? Something sitting in the dash perhaps?

Any ideas would be greaty appreciated.

Mr_Shiftright

Does this car have a lock-out button for the windows?

300cdveggie

Yes, but we've tried the botton in both positions. Could the lock-out fail and cause the windows to not work?

260eman

I just purchased an '89 260E with 100k. Engine runs great. Car shifts fine, except it will not go into 4th gear. The transmission is so smooth that you wouldn't even notice it if you were not looking for 4th gear. Anyone have any ideas? I would hate to have to get an overhaul. If I did, how much should I expect to pay? Thanks.

ryan66

I have a 1982 300D. I haven't found an owners manual yet. Anyone know how
to get dash lights brighter. Also, there is a thumb wheel on console. Can't figure
what that's for. Thanks.

Mr_Shiftright

just pop the lock out switch and by-pass it and see what happens.

87mb300d

I have a 1987 MB 300D with the original radio. The car is stored some of the time (due to weather) and the battery occasionally goes dead which locks the radio. This is prior to the code radios where you can type the code into the radio and it will unlock. Therefore I have to take it into the dealer to unlock (a pain) but they don't charge me. The dealer said they cannot sell me the tools to do it myself for security reason. Is there a place\website I can get these tools? Or better yet a way to make a home-made tool? Also what is the process for unlocking once you have the tool? Thanks.

opsterusa

I have a 380 SL 3.8 Automatic. When I shift into drive with brake depressed the car Rises up about 2 inches. When I go into Reverse it lower the same amount. I have replaced the differential mount and transmission mount. Engine mounts are good. Anyone have an idea?

Mr_Shiftright

Weak suspension would be my guess...shocks/struts. Does the car bounce around a lot and feel wiggley in the curves.

ryan66

More questions. As for the dash lights, is there a control knob to make them
brighter? Used car last night. Had heat, but only high fan speed. Is there only
one setting?

goldcar

If it is the thumb wheel by the hazzard light switch, that is the radio fader. It should shift the sound between the front and the back speakers.

goldcar

I kept isolating the vacuum system from various sub systems until I found the problem. I discovered that if I disconnected and blocked off the line from the interior components, the engine shut off fine. I checked the door lock system again and determined that it was fine.

Eventually, I disconnected the line going to the climate control and blocked it off. Now the engine shuts off fine and the door locks work. As I live in San Francisco and rarely drive out into the heat, I have yet to be motivated to tackle the climate control. Plus, some of the settings seem to work anyway.

I have noticed that the middle two vents on the dashboard never blow, but the side ones blow fine. I suspect a bad actuator or a vacuum problem with the main control unit.

samcat1

Wife's car -- quit on road. Starter turns over and engine fires for a couple of seconds then stops. Only tried it a couple of times to avoid exascerbating damage. No oil or other fluid leaking.

Could it be starter somehow engaged while running?
Great car with really good maintenance and for the record, the forum is dead right regarding windows and A/C problems and repairs! Once all problems fixed, they stay fixed..

Mr_Shiftright

Change your fuel filters (both of them) and try again.

pilotpatc

there is a little ceramic pot on the back of the instrument pannel. they burn out a lot. they can be replaced or just wire around so it's max all the time, which isn't very bright. also replace the bulbs while you have it apart. i painted the needles also. careful not to get any paint where it touches the pegs on the speedo and the oil pressure. they will stick afterword if painted.

pat

samcat1

Thanks for quick reply
Both filters just replaced -- turn key and starter sounds "normal"; engine starts nearly immediately then high-pitched sound and engine quits. Sound is roughly like an engaged geneva gear. Any thoughts??

ryan66

Thanks for responding, pilotpatc. Do MB's have adjustable dash lights? How do you brighten/dim them? Also,is there only one speed for fan?

samcat1

Found the answer! Stupidity! Air Conditioning compressor frozen! It was a damn rebuilt. I never thought to turn the A/C off. Of course, as soon as I did, car started up immediately and runs perfectly.

Horrible noise was brand new belts trying to slip.

Mr_Shiftright

Ah beat me to it!! Anyway, you got new filters, which is good. Which compressor do you have in there...the high mounted one up top of the engine or the low mounted one on the drivers side? The high mounted compressors are total junk, don't even bother to rebuild those.

brakeengr

try crutchfield.com for the tools

captron

so, I finally have the glow plugs. How do I replace them? I'm totally illiterate. My buddy has tools, but no diesel no how. Diagram? Schematics? Thanks!