Mercedes 300D Suggestions

skeeter3

300cdveggie,
I have a 1982 300D. I am having the same problem as you. How did you get power to the switches to get you window up? I have checked everything possible. Changed fuses,Swaped out the relays that are located on the drives side wheel well located under a black cover. I tried supplying power to the switches and did not succeed. I even took the switches all apart and cleaned them. I am pulling my hair out!!
Thanks!

brakeengr

On my 1982 300D, I had similar problem on my driver's side window- couldn't get it down. Other windows were fine. Just by accident I discovered that if I pressed the switch down very hard, it worked. Getting the window up was no problem. Now, it works normal. Just pressing the switch very hard a few times seemed to set it straight!

skeeter3

I took all of my switches apart and cleaned them. So i think its not a switch problem. Thanks for your input. I finally got them to go up by jumping the switch with 12v. Now i just need to find out the main problem.

coldbenz

I need some help, I have a 1982 300d the heating system is the problem, when the car is at idle I'll get some heat more like luke warm air but as soon as I start to drive it turns cold. The aux. pump works because at idle it's running and I get some warmth. Is this a monovalve problem?

mercbguy

Are there any pros and cons to using #1 in place of #2 diesel ? I have an '87 300SDL and I don't seem to get any soot on the bumper over the exhaust when using #1. When I used #2 consistently I did. My access to #1 is through one supplier but #2 may be through 3 or 4 suppliers. All are high volume stations so would imagine the fuel is "fresh". There is no noticeable difference in mileage or performance. Does anyone have any experience with both fuels ?

mizzmugg

Thanks for the advice, but after calling a locksmith I am having the tumbler replaced. Few people can do this because it requires a "special" tool that only MERCEDES technicians have access to. It may turn out to be a fairly expensive repair. Did mwulfe solve his problem in
#850 message?

brakeengr

check your coolant level. If low, you won't get heat.

dpotter1

Can a 1975 300d hood fit a 1979 300d?

Mr_Shiftright

Depends if they are both W123 chassis or if the '75 is a W115 chassis.

mwufle

Thanks, but nothing worked. I had to have the tumbler replaced by my Mercedes mechanic - it was a very expensive repair.
Good luck. mwufle.

focusintexas

Mr. Shiftright, I recently bought a 123 euro 300D turbo. question: its a 300D turbo but it has virtually no pick up compared to my 300SD. do they have the same engine? the 300D is i suppose from the gray market. also, on the freeway, the speedo reads 80 mph when i know for a fact that i am running only about 60 or 65. Is there a difference between the euro and U.S. versions? Thanks and I hope for a speedy response. I love my 300D though althoug I know it needs TLC by now.

Mr_Shiftright

Yep same engine (OM617A). If the 300D has a lot of miles on it, maybe it's just tired or perhaps the turbo isn't boosting properly. People expect these cars to run forever but they wear out just like any car does after all. If you've over 200,000 miles your engine is probably in need of at least a compression test to see what's what and the turbo should be checked for boost, leaks, etc.

zmeister

Hi. Bought an 82 300D Turbo about 2 months ago. My first MB. Reset valves and patched vacuum leaks so that now tranny shifts smoothly and get okay power. (well except for Low end power).

Few days ago, popped a hole in my exhaust, either front pipe or front muffler. Low RPM power improved dramatically. slightly noiser but GREAT power. I was amazed at the improvement. Wondered about the impact of 1. leaving hole and keeping windows open. 2. patch hole but removing one muffler to reduce obstruction. 3. Going to a larger muffler to reduce obstruction. Anyone???? ZMeister

Mr_Shiftright

On a turbo car, which has the turbo in the exhaust stream ahead of your "hole" anyway, the effect of a free flow exhaust system might give you oh 2-4 HP.

Just keeping a hole in the exhaust is not a good idea...you can harm your valves doing that, so that's a no-no. You need some "backpressure" for efficient operation of your engine.

Is it worth 2-4 HP to spend $300-$400?? Probably not.

zmeister

Thank you Mr. Shiftright.

Your point is well taken about the need for back pressure. It's just that I still get queezy pulling out into traffic from a stop. The extra 3 or 4 horses at low RPM seem to make a dramatic difference.

Would patching the hole and then removing one of the two mufflers make any difference do you think?

Thanks again for your expert advice. ZMeister

Mr_Shiftright

Do you manually shift the car at all? This can certainly help, if you start in L and work up through S and D.

You might gain a little power taking off a muffler but the car is going to be very noisy at highway speeds I think. You could try it.....

zmeister

Hi,

Yes, when rapid access is a concern, I will put trans in 'L' to try get boost up quicker, but it still will shift from first to second while in 'L'.

I just got home and again, subjectively, with the small hole, it seems so much more responsive.

I did wonder whether one of the mufflers could be clogged (although the entire exhaust system appears new) or else if it mufflers were aftermarket and not synched properly to manufacturer specs (although they have the MB style brackets for the rubber rings).

Thanks for your thoughts on this compadre.

ZMeister

focusintexas

Thank you for the response. if it will be prudent i will invest in a used 300D engine that is available. i like the size of the 123 and the power it can give, if i have an engine that is not so tired.

Mr_Shiftright

Certainly a clogged or incorrect muffler can seriously affect performance, yes. They don't "clog" so much as deteriorate internally, sometimes rusting, and then baffles or packing inside fall into the exhaust stream.

zmeister

The exterior of the mufflers look clean and rather new, but I have a suspicion they are not MB units but rather aftermarket lookalikes. The front pipe looks rigged. I'm going to pursue that option. First I'll remove the front muffler and see how the car works, and IF it's too noisy, I'll order an MB muffler to replace it.

Thanks.

zmeister

The rear springs on my 300D Turbo are less than perfect. I noticed that the gross weight max allows me like 900 pounds additional weight for passengers and luggage, and with 4 people in the car it rides REALLY low in the back.

Am I better to replace the springs or to use spring adjusters or other spring helpers, or to get spring assisted shocks? (current shocks seem ok)

If the better way is new springs, should I remain with MB replacement springs or get heavier duty springs? If adjusters are better, what style would you recommend?

Thanks.
ZMeister

Mr_Shiftright

This may be a problem with the hydro-pneumatic compensator rather than the springs.

corv

I have an 85 300SD. I have balanced all wheels and at 60 MPH it feels like the wheels are out of balance. I have checked and am shure the wheels are not damaged. New tires are in great shape. At 60 MPH the steering wheel begins to shake as if the wheels/tires are out of balance but I know they are not. Please advise. Thanks in advance. Ed.

Mr_Shiftright

Back to the balancer...have them put a run out gauge on the tires, or switch tires front to rear. I think you still have a balance problem and you might need a more clever shop to cure this (with better equipment). If this doesn't do anything you'll have to examine the steering shock, alignment values and front end parts.

corv

What is the smokey white stain/color on the back of my 300SD? It appears on the bottom left and right of the back wendshield. How can I get rid of it? New glass? Please advise and thanks in advance. Corv.

Mr_Shiftright

Well I can't see it but it sounds like a typical form of delamination, so new glass would be in order.

nectarpro

what is this cone like gadget that is connected to the breather hose. does the bottom connect to anything? I recently changed my air filter and do not know if the cone thingy's bottom connects to anything or not. right now i got it connected to somekind of pipe coming out of the manifold area. do not know if this is correct or not.

nectarpro

Just to clarify. I have a 1980 300d. In all the books I have it does not show this cone in the pictures and I can't figure out what it is. There is a black hose coming from the engine that connects to this cone which is inside the air filter housing. Anybody know what this is? anybody????
A tube runs through the cone and I am not sure if it is supposed to connect to something on the bottom or not, or what it's function is.
If anybody can help please reply. Thanks!!!!

partzee

My son has a 1984 300D turbo 4dr sedan automatic and it stopped shifting into high (4th) gear.Other shifts seam to be OK.
Any and all help will be appreciated.
thanks,

Mr_Shiftright

Why don't you pull the dipstick and smell the fluid. If it is very dark brown and has a burned smell, then that's a pretty bad sign.

partzee

Thanks,
I should have said, we checked the fluid and it's in good shape,nice color, and at the right level.
Thanks

Mr_Shiftright

Well there are no electronic controls on the shifting process so one would have to suspect a gummed up valve body/clogged filter or defective internals. You could do a trans flush and filter and see what happens; otherwise you'll probably have to at least drop the valve body.

ppilot1

Guys, this a great discussion forum. I have read most entries. My question has to do with pricing of the 1985 300D / Turbo and earlier 123 body styles. Suddenly I am seeing prices locally in the $5K range for 150K and above miles! Has every one lost their minds, or do they know something I don't know? Appreciate your input/thoughts!

Pilot

partzee

Many thanks,we'll try that.
Thanks,

Mr_Shiftright

Well it's supply and demand that's driving prices. Where I live, there are a lot of these cars so prices are lower. But for $5K it had better be one HELL of a nice car. A person might ask a premium price for an extra clean, low miles turbo, but paying a high price for a non-turbo 300D is kind of silly.

150K isn't too bad---there could be another 100K left in the car before you start throwing serious money at it.

Over 200K with no engine work? forget it---no way I'd pay $5K or even close to it. Let the unwise buyer buy those cars at those prices.

ppilot1

That's what I thought Mr. Shiftright. *Making a mental note to move to Mr. Shiftright's location*. The Dakotas, is that right?
Thanks for your wise and valued input. I have my eye on an 85 300 Turbo. It is almost perfect inside and out, with 119K on it, but the guy is asking $5500 (and he does NOT have service records) Drives nice and meets all the "things to watch out for" criteria this forum has discussed. Next step is to get a Benz expert to go thru it. Will report here what I/we find.

Pilot

Mr_Shiftright

It's a premium price but not unreasonable if the car is really top notch and if the miles are correct.

rjp3

HELP PLEASE!!
I have a '99 300D Turbo w/70,000m. I've had an ongoing problem that seems to be fuel related. I changed the fuel filter which helped for a while, then when I got to a 1/4 tank it began stalling. I added injector cleaner which helped but then at start-up the car began stalling out. I'd spray starter fluid before the air filter and the car would fire and resume normally. I noticed air bubbles in the clear hoses @ the fuel filter which the local service manager hesitantly to me that I was sucking air due to bad hoses/o-rings. I've just replaced the hoses and I'm dead in the water. The hoses remain clear of fuel after several trys at starting.
-Do I need to prime the hoses?
-Is there another fuel filter other than the front canister filter?
-Is the fuel pump mechanical or electric?
-Is there a manual/CD out there-The dealer doesn't offer one?
Thanks in advance-rjp3

Mr_Shiftright

Yes you may have to bleed the hoses while cranking the engine, unless your pump has a manual primer. I'm sorry I'm not entirely familiar with this late model. No doubt you have a mechanical fuel pump for a diesel car.

I'm not so sure about this "sucking air" theory either. If air can get in, why can't fuel get out?

I think you may have dirty injectors and that was your problem from the get-go.

rjp3

Thank you for your reply.

Well, I got it started, but I still have air bubbles in the lines. One thing I failed to mention was that the dealer was out of 2 of the 6 lines which I'll get tomorrow and install.

I just took it down the road and it seemed to run better than before. Then it stalled at the same location it used to, only this time it wouldn't re-start. I got a tow.

-Do you have a recommendation where I might get a service manual?

Thanks Again rjp3

Mr_Shiftright

must be a fuel delivery issue...it's very odd for a diesel engine that's warm not to start, unless it isn't getting fuel. I wonder if you have a helper pump that pumps fuel to the main injection pump.

jrlncal

I had that same problem, a real mess. The problem is that the oil pressure gauge on the dash has a live oil line to it, not an electric line. That line has a leak. You want to fix it prior to if filling up the whole dash area with oil.

John

rjp3

Update-I replaced the remaining 2 fuel lines Friday and the are bubbles disappeared. The car runs great! I guess these lines are on the suction side of the fuel pump allowing the air in but keeping the fuel from leaking. I don't know about a "helper pump", in fact I know very little about this engine, but I'm learning. Thanks again for your input. I just found this forum out of desperation last week and can't wait to have the time to browse throughout it.
Thanks Again, rjp3

ike7

I have a 1984 300D Turbo with 145k miles. It ran strong until recently. It seems to be fuel starved. I changed all fluids/filters 5k miles ago. I can still baby it up to freeway speeds, but if I go up hill I drop down to 40MPH - at best. The turbo charger seems to be working, it starts and idles with no problem. Any ideas before I am at the mercy of a mechanic??

Mr_Shiftright

How do you know the turbo is putting out proper boost? You need to check the boost. Also another filter swap wouldn't hurt. Fuel tanks on old diesels can get pretty foul.

dropnosky1

hello, I just recently picked up a 1982 300D non turbo, and I am running into serious starting problems. I have tracked the problem down to one of the glowplugs failing and messing up the others. My question is this, on this paticular model, a german sold car that was actually imported by a private party, hence the non turbo of that year, it has the j shaped filiment plug style. I would like to change to the pencil type plug, but would that need an alteration of the wiring? and is it really advisable depending on the difference of the plugs? What I have read on the subject is that after 1980, they mostly came with pencil type plugs, and were wired in paralell. My feeling is that someone put the wrong style plugs in which may have caused them to fail. Can you do that? or is it just another one of the million differences between the german and us import cars. I am new to this subject, and any info would be much appreciated.

prequillart

hi there, I am thinking of buying a 1982 300D. It has done 460,000k. Any idea how much mileage it has left in it. I realize it depends on a lot of variable, but what can I reasonably expect? Anyone?

Mr_Shiftright

Glow Plugs are expendable, they wear out normally and should be replaced every couple of years. Just replace what you have in there....they are fused so I can't see how one could case the others to fail. The non-turbo 300D W123 chassis was made all the way up to 1985, so there's nothing unusual about a 1983 300D without a turbo.

Mr_Shiftright

If it's got the original motor in it, you can expect it to fail any time now. That's close to 300,000 miles. The car is basically done for unless it's been restored previously.

But if it's cheap and runs well, no harm done in buying it---just don't put much money into it---I'd rather see you spend more for a lower miles car or a re-furbished one, than for an old beater. Whether an old Benz costs $1,500 or $15,000, it costs about the same to fix it.

bnsbnz

I am not sure you have solved this problem but I can help. There are a few reasons why you might have oil on the floorboard, and the oil pressure gage is pretty unlikely to cause it unless the line has been fairly abused at some time. Another reason can be a deterioriating engine stop. This is located at the end of the injection pump and is how the car shuts off via vaccum. If it is slowly deteriorating it will bleed oil into the system. Since many under dash components (heating vents primarily) are run off of vaccum the oil is sucked into the engine compartment. If the oil line was off the gauge you would more likely have a swimming pool in the footwell not a small pool, it constantly would poor oil into it.