Mercedes 300D Suggestions

prequillart

thank you mr shiftright, i'll have a closer look at the maintenance book. It had only one owner who did all the required services on it, the car and the engine look great at first glance and the engine starts as you turn the key. They are asking $5000 Australian (US $3750.

Mr_Shiftright

Kinda high in this country for that many miles but I don't know the market where you are, so....I think you are doing the best thing by checking maintenance records.

Starting right up when cold and/or warm is a good sign for a diesel...if they crank and crank before they start, this is usually an indication of a worn engine---since compression is the only thing used to start the engine....

Also make sure the heater controls work and that the rear tires don't show extreme negative camber.

prequillart

forgive my ignorance. English is also my second language, but what is negative camber?

Mr_Shiftright

That would be when you stand in front of, or behind the car, and you look at the wheels, and the tops of the tires seem tilted "in" towards the center of the car. On an old Benz, in the rear suspension, this means a worn hydropneumatic compensator.

dyates773

I need help and advice. My 1987 300SDL is smoking to the point where it is now undriveable and will not idle. Here's the basics: 245,000 miles, new glow plugs in 2005, new injectors in 2005. Smoke is blue(clouds of it) but oil consumption is less than a quart in 2500 miles. Starts right up but will not idle, will run smooth above 2000 RPM. The turbo boost seems fine and the car runs great at 75MPH with steady light smoke.

I'm thinking the injection pump may be dieing. Any thoughts?

Any tips on pulling the pump to be overhauled? Thanks

Mr_Shiftright

I bet you are sucking oil through the turbo. If not that, and smoke is in fact blue, you could have bad valve stem seals and worn valve guides. If not that, then the rings are wearing out. Diesels run at very high compression, so the rings have a lot of work to do.

All this is testable. I don't think the pump has anything to do with it unless the smoke is actually black and sooty.

Odd that your oil consumption isn't more given all the smoke. Have you had someone following you to report the ifs and whens of the smoke?

A leaking turbo usually smokes worst at start up and gets better as the engine warms up. Bad guides and stem seals smoke mostly on deceleration. Oil rings smoke all the time.

prequillart

hello Mr Shiftright. Thank you for your very useful insight. I went to look at another 300 D today, it's a wagon and again the body looks great, here in Perth Australia we have weather similar to southern Cali. It's done 175,000 miles and the guy wants A$4,000 (US$3,000) Anyway, the engine started on the first crank, no major oil splashes on the underside, the AC works (although when i turn the heater on and the AC off, cold air still comes in the middle vents and hot air comes from the two side one ???)doesn't look like it's got any negative camber at the back although all 4 wheels are unevenly worn(all 4 more worn on the outside)So far so good (except that funny AC/heating problem) BUT

-The engine idling sounds a bit high pitched, even after it's warmed up , could that be the valves clicking?

-no history or records of maintenance.

-took it for a drive and when switching from 2nd to 3rd (automatic trans), it stays in neutral and the engine revs up and then it decides to properly switch. also when slowing down, it doesn't seem to down shift fast enough, as if the car is just rolling in neutral. Is that VERY bad or does it need only minor adjustment or maintenance

Any suggestions?

by the way the wagon looks great with the chrome roof rack, i love it.

Mr_Shiftright

The wagons usually are more valuable, so price seems right. The transmission symptoms are troubling...you might take it to a shop and have a look. Is the fluid dark and does it smelled burned? Perhaps a good transmission service might help. You can always drop the transmission pan on the car and look for bits of metal debris. If you see a LOT of metallic particles that's not good, especially brass.

If the tranny is bad, perhaps you can bargain way down. A diesel wagon would be worth putting a new trans in if the rest of it checks out well.

lsimon

Help...I have oil in my air filter! I know this is not right. I have a 1979 turbo deisel that was not orginally a turbo, but they converted it to a turbo deisel. I'm not sure how to keep the oil out of my filter and what steps to take next. I have been get blackish smoke when I start the car. I also have recenly been getting 100 miles less per tank...oops. SO, where do I go from here? Laura

prequillart

thank u mr shiftright, i 'll have the transmission thoroughly inspected. What do you reckon of the simultaneous AC and heating?

Cheers

Mr_Shiftright

Sometimes those climate control systems are just SLOW to respond. You may find if you give it a minute it will correct itself. If not, there's probably a vacuum leak somewhere...I presume you mean *cool* air out of some vents and warm air out of others---not that the AC and heater are actually on at the same time.

Mr_Shiftright

Probably that's "blow-by" from a worn engine---fairly normal on old diesels if the engines haven't been rebuilt. what happens is that the compression rings are worn, and so part of the explosion of the diesel fuel zips past the rings (which it shouldn't do), blows into your crankcase, and the subsequent pressure blows oil and gases into the upper engine---where the air filter gets a small dose of it.

As for black smoke this is the product of incomplete or poor combustion. This could be bad or clogging fuel injectors, or a malfunctioning injection pump or a filthy fuel system. You might try a very strong injector cleaner in your fuel tank, and also change both your fuel filters when you do this. A product called BGK44 is very good. You may have to repeat this dose a few times to get results.

If your injection pump is bad you probably need to look for another car.

As for the blow-by, there's really nothing you can do as a rebuilt engine isn't worth the cost on this car.

soybenz

Injection pump overhaul will be VERY expensive - probably more than the car is worth. Try other options first. If you are not using much oil, then you might still be OK. My '84 300D had similar symptoms, but after valve adjustment, new injectors and injector timing adjustment: no more blue smoke (well...just a little bit when it first starts up).
I would first get the valves and IP timing adjusted. Then I would do a diesel purge - remove the input fuel line and stick it straight into a can of sea foam, so the car is burning straight sea foam. Start it and let it run till it drinks it all. Should smoke like hell. The unused portion will return to fuel tank via return fuel lines - that is OK. Hopefull this will clean things out a bit. Search for diesel purge at dieselgiant.com.
Good Luck.

Mr_Shiftright

Oh yeah, valve adjustment is a good idea. Pump timing can be checked but only by a very qualified shop...no amateurs playing with pump timing PLEASE!

I also like the diesel purge idea for step one, and checking valve adjustment is easy.

benzbound

I am currently looking for a new family vehicle and have read this entire forum to get familiar with this car. Having recently relocated to a rural area I find myself on small texas farm to market roads that have speed limits of 70 mph. My question is this: Are the mid 80's 300's any safer than the early 90's? In the price range I'm looking, I can get a mid 80's 100K mile car for about the same $ as an early 90 with higher mileage. Also, are the older ones any better built than the 90-91 models? I read a pitch on an ebay sellers description that claimed the 350's were "just bored out versions" on the 300 and had lots of engine problems. Any opinions out there?

dyates773

The valve adjustment was one of the first things I thought of. I've done the adjustment on my '79 300D but the '87 300SDL is a Six Cylinder with no rocker arms. I didn't see the adjusters as it appears the overhead cam operates the valves directly. Did I miss something?

Mr_Shiftright

I think the SDLs are hydraulic. Forgot about that!

Mr_Shiftright

I'd agree the 350 engine is not good, and I'd avoid it.

As for safety, you can't beat a car with an air bag.

However, if you are in a really remote area, the simple the Benz you own the better off you are in my opinion. Personally if you are really REALLY in the sticks, I'd buy a toyota!

Old cars are old cars, and they will break down.

benzwagon

hi guys, new here..read thru alot of these messages prior to buying my 83 300td, learned alot before even looking at any cars..this is a great site, heres my question, 205k on this original trans..shifts good when warm, w/ the occasional flare between 1-2 i think? but flares alot! when cold..but if i shift manually, it snaps right into the next gear like it has a shift kit. i did change the fluid and filter hoping for a clogged filter, inside pf pan was super clean, and the fluid looks and smells as good as new. im willing to bet its been along time since it was ever changed just do to the condition of the outside of the pan..(20 minutes of cleaning prior to pan removal)the previous owner said its shifted like that for the 9 yrs he owned it, second question is i see alot of the cd manuals on ebay 83 thru new? should i be careful of the quality of these cd manuals? thanks for any info..again.. really enjoy this forum.... Rob

burdawg

What do you mean by a "flare"? A hesitation?

Mr_Shiftright

I think I know what he means...a kind of slow, sloppy shift...a "soft shift".

Probably just hardened seals in the valve body...old age...not much you can do but live with it until it gives up...

benzwagon

welp....guess all i can say is too long of a space inbetween shifts...which allows the engine to speed up...way up..then it engages..on the rest is fine..but again..shift manually and all is perfect..also..seems slow from reverse to drive ...drive to reverse.. when warm no flare..(that ive noticed) but shifts too soon...in fourth before u know it...thanks..rob

goldcar

What should the air filter look like on a 300D? Mine is covered in oil, but otherwise clean. Is that normal? Should it be changed?

Mr_Shiftright

how can it be covered in oil but "otherwise clean"?

burdawg

Have to agree with shifty on this one -

arife

We own a 79 300SD. Last winter no heat. Replace AC vacume behind gloove box. Beginning this winter our heater went out again. Needed to replace the main vacume unit at great expense and the AC vacume behing the glove box. Today the blower stopped completely and the glow plug light started flashing after the car is started. We still have heat but it doesn't help to defrost the windows in the morning because there is no blower.
Fuses good. Ignition switch seems good. Please help.

benzwagon

well again the sellar claimed its shifted like this for a long time...maybe once i find some manuals, there might be some adjustment? we'll see.. so back to the manuals. still looking on ebay, i see the cd style manuals which interest me because my pc is right in my shop, so refrencing it wouldnt be a big deal, my concern is the few ive see have stated they cover from 83 to presant? why doesnt that sound right to me?..hate to get something that ends up as useless as a chilton's or.... very impressed w/ this car so far..going to pick up a parts car tomorrow, i need to replace the rear tailgate and graft in a new rear corner..but other than that the car is pretty nice..amazed w/ the ride of this 23 yr old car w/ 205k on it.. thanks again...rob

Mr_Shiftright

You want the 3 volume factory manual set...anything else is useless for transmission work. I'm not sure which CD you are referring to, but if it costs $19 or something like that, it's also pretty worthless.

I'm fairly certain your symptoms are just old age....do a service on the transmission if you haven't already, otherwise don't fiddle too much with linkages, etc. You could end up worse off than you are. But if you had the 3 volume set at least you could adjust everything within spec properly--though I don't think it's going to help too much in this case. But hey, who knows with these old beasts? Sometimes they heal themselves!

benzwagon

hi, i agree ,, u never know..ill try to adjust things in when i find the right manuals, maybe ill luck out, or maybe when its cold.. ill just shift it manually, anyways, just got back from picking my wagons sister haha..same guy had a parts car..its really rotted but pretty much all there, gonna strip it right down to nothing save what i need and maybe sell the rest, my good car was a basic model? no power windows or climate control(which i was happy to see..this parts car has that all and it seems to be all working, maybe ill list it somewhere in this forum for others to view? (if thats ok?) trying to get the parts car running..cranks real well, but no glow plug light, and not even a hiccup out it..the glow plug relay doesnt seem to be even clicking..just wanted to hear it run before pulling the motor, its been sitting a few yrs..but i expected atleast a cough or sputter? ill keep my eyes out for the 3 volume set.. thanks for the info....

benzwagon

hi, been reading thru the posts...found a post about clogged roof drain, my 83 300td is almost rust free except to soft spots ot the rear seat foot pan, notice after bringing it in the shop today after a brief rain water was leaking from these 2 "soft " spots in the floor..checked door seal and headliner..all see dry,,,pushed a rod thru the drain holes in the rockers..nothing came out? thinking maybe a clog at some point w/ maybe water freeze bursting a hose in the door pillars? am i thinking to much? haha..any known problems? also...have 83 300td parts for sale from parts car..place to post them other than ebay? ill be honest havent read everything about this forum, dont want to offend.. i do enjoy reading all the tips..great site...rob

brakeengr

I have bought the 2 CD set from ebay- other than some basic stuff, it's junk.

benzer2

I just purchased an 87 300D TD and I'm having some trouble with the switch that lifts the rear headrests. I'm not even sure where the fuse panel is.(I just bought it yesterday.) Also, shouldn't there be a plug located on the outside of the car somewhere to keep it from freezing?

benzer2

I just read the post that gave instructions to add redline diesel additive to each fill up. Is this easy to find? The only diesel I've ever owned was a 91 Ford p/u and I was very happy with it's performance. Of course the 300TD I bought for extremely different use but I've heard great things about Mercedes diesel engines. The previous owner let the diesel freeze so I'm replacing the fuel filters. Is there anything else I should do before driving it?

300d

Hi shifty,

I've noticed that the HP # for the 617 engines are higher in 83 and 84 than in 85. the only reason i can see for this is the adding of the EGR valve. SO what i'm propsing is to put an 83 or 84 manifold on my 85. It seem simple enough but with the vacuum system being so complexe theses cars i would hate to screw somthing up. Do you know of any one who has done this before and if so what problem they ran into? Do you know the system well enough to point in the right direction? also does the engine require an back preasure? So if i choos to run a strait pipe back the engine will still run correctly?

thanks,

JJ

Mr_Shiftright

Keep in mind that anti-gel additives aren't necessarily the same as regular diesel fuel additives. If you are in a really severe climate you can add a little gasoline but check with Benz to get the right proportion because I don't remember.

Yes Redline is easy to find. Read the back to find out what application you are buying it for. Kragen and Autzone should have it. It should say "anti-gel" right on the front.

Mr_Shiftright

I really don't know if this is possible but certainly manifold design can affect HP to some reasonable extent.

All engines require backpressure for the right balance of fuel economy, power and longevity, yes...at least all normal passenger car engines...a P-51 Mustang fighter plane, maybe not. It has been shown on dyno testing that even too large a diameter exhaust pipe can decrease engine HP.

benzer2

I live in Nebraska which is definitely a cold climate, save for this year, and if there is a block heater on this car I sure can't find it. After the diesel gels, is it just a matter of letting it thaw before it will work?

capthavoc

Hi. I just found Desmond in a field, traded a lawnmower for him and towed him home. He's a little rusty, with 285K to his credit. I adjusted the valves (found a newly rebuilt head and new crankshaft under the goo) and he runs fine. I had a lower radiator hose heater and put it in, but it doesn't seem to warm the block. Is this due to the vacuum controls? I'm in northern Maine, so I kind of need it. Thanx, Jay :

Mr_Shiftright

Could be. You may need to bypass that valve system.

You can spot an engine heater very easily because there's an electrical cord hanging out somewhere in there!

focusintexas

Same problem with my 84 euro benz 300D Turbo. 1st to 2nd gear it short of gives me whiplash... or i have it already. is this part of the model? also, lately i notice a "whirring" sound coming from the rear differential. is it damaged from the whiplash gearshifting? HELP! what should i do to remove the whirring and beginnings of vibration in my car.

Mr_Shiftright

Those transmissions shift very hard, especially as they age. If yours is equipped with a vacuum modulator, replacing that might help a bit. The whirring is probably just differential gear wear. That could last a long time without worries. Vibration is often a driveshaft or rear tire balance issue.

swiftsure93

Hi: I have just bought a 91 300 TD and have the smae issue. ALong with the rear headrest switch that doesn't do anything the trunk and license plate lights are also out. Let me know if you get an answer that will help both of us. The fuse box is under the hood in front of the driver (sort of over his knees). It's easy to get to and the circuits are labelled on the inside of the lid. I've checked and moved all the fuses on mine and no joy.
Paul

capthavoc

Thanx for the info on the hose heater. I leave it for 4 hrs when below zero, and presto! Now, does the sunroof have drain tubes along the side runners? It appears to be full of 25 yrs of detrius. I changed the glowplugs, siliconed the rear windshield with black rtv, and I'm styling! What a great car! Prices on parts are a third of volkswagons (ex-diesel jetta owner). Reading thru the posts to try to cure the transmission/vacuum/linkage issues, sounds common. I'll keep you posted if i discover anything helpful J

focusintexas

Thanks! i will look for the vacuum modulator and replace it. mr s can i email you personally because i want to show u the pic of the engine and i have a few questions to ask you about it. let me know

Mr_Shiftright

sure. Will help if I can.

280ce81

Backpressure? I have a 300D that is laughably (actually hazardously) slow. Previous owner said turbo is gone. Also, downpipe from turbo to exhaust non-existent. A reliable(?) mechanic said that as long as the car starts fine (which it does), then rings and compression are probably o.k. Does this suggest some (not-too-costly) diagnosis-repair, or is it engine time? It's a second car for me, but I would love to drive again...

Mr_Shiftright

Well if you have a turbo diesel with a non functioning turbo it will be even a worse cow than a non-turbo 300D. You can't use the car without the turbo---that's the whole problem that needs to be fixed. The engine was designed to be used with a turbocharger.

benzer2

Hi there,
After doing some reading and experimenting I discovered that the rear headrests are only let downwith that button. They have to be raised manually by the passenger(s) in the back seat. This feature is for the driver's added visibility should those headrests be left up. I was under the impression that they went both up and down with the switch. If it's the bulbs on the trunk and license plate that are out those are a pretty simple fix. If not, and no fuses are out, then you might have to have an electrical system check performed.

hookedup4door

Hey! I'm new to the forum and the car. Is there a wanted/for sale section? I'm looking for a third row seat with belts, front lip and middle seat headrests.

Mr_Shiftright

nope, no direct classifieds are permitted in these forums. For something like that you should cruise the speciality Benz forums. Those parts will be hard to find so you need to zero into a really narrow user base type of forum. Or eBay of course.