Diesel purchase question

I'm looking for a nice older MB TD. I'm seeing 5 cyl & 6 cyl, and hearing only rumors of what is best. What are the recommendations of such knowledgeable folks as you?

Reply to
L A Davenport
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As new as you can afford... full service record is best... bring a buddy who knows alot about MB or take it to a MB tech to have it inspected...

And test drive it well... so you get an idea what is normal and what is not.

Reply to
Tiger

The 5cyl in mid 80's and older diesels has a cast iron block and head, you can't kill them. The later 6 cyl's (3.0 L) had aluminum heads, that could warp or crack if overheated. The 3.5L 6's had trouble with the cylinders...not sure of it is the correct term, warping, changing from round to oval shape.

Reply to
sdp1

I've owned a 77 240D, 80 300SD, 84 300SD and (currently) an 87 300TD, so I've had experience with 4, 5 and 6-cylinder diesels. All are excellent, but I feel the best engine overall is the

6-cylinder in the 86 and 87 models. It is the smoothest, most powerful and gets fuel economy comparable or better than the older diesels. Yes, if overheated the head can warp. Mine has over 220K and I've never had the head replaced. I had a new radiator installed two years ago. If you're careful and keep the cooling system in good condition head warpage should not be a major issue.

I would definitely stay away from the 3.5 liter 6-cylinder diesel found in the early 90's cars. They had a disasterous record.

Reply to
jav

The only diesel i have owned is my current 86 300SDL with the inline

6, which gets 22city/25 highway, compared to (told from owners) the same generation 300SD's with the inline 5 with gets 28city/32 highway. They get almost 600 miles to a tank where i am on empty just over 400 and i have a bigger tank.
Reply to
sdp1

Those mileage claims for the 5 cylinder are bogus, unless the gallons are imperial gallons! 24 mpg in commute driving is about the real number.

Reply to
T.G. Lambach

The five cylinder diesel is really the old 4 cylinder 240D with an additional cylinder grafted on. That was done in the mid 70s to achieve about 77 HP. In 1978 the internals were strengthened and a turbocharger added for the first 300SD Turbodiesel (110 - 120 HP). The engine's technology is old and quite simple, a great engine for a DIY owner.

The engine's maintenance is oil & filter change at 5K miles, valve adjustment at 15K miles and filters at 30K miles. The engine will be good for 250K to 300K miles if it is so maintained. These old fives are all cast iron and very durable machines. Their other advantage is that lots of them were sold so finding a used engine isn't difficult.

The newer six is a more powerful engine (148 HP) that's also inherently smoother, being a six rather than a five. It's aluminum head is not as durable, its cooling system must be well maintained to avoid overheating that causes cylinder head and or cylinderhead gasket problems.

The internal condition of any diesel will be revealed by a compression test and I suggest you have one done before, not after, buying one. Its $$ well spent to know that you have a good car or to avoid an expensive lesson later on.

Reply to
T.G. Lambach

I was a hair off, but not much. Original EPA ratings were 26city, 30 highway (for a 300SD w126). Any idea why they stopped production of the w126 diesel after 87 until the 350SD and SDL came out? If the body style was still popular and diesels were still being used in other models and again in these, why the gap?

Reply to
sdp1

The gap was likely the falloff in sales of diesels in general because of the decline in fuel prices in the late 80's, not any inherent flaw in the diesel engine themselves. Among the most talked-about and highly sought after diesels are the 86/87

300SDL and the 87 300 TD-T. Low mileage specimens in excellent condition are readily sold on the used market.

Regarding fuel economy, I maintained my diesels in excellent condition, used primarily Mobil 1 oil changed regularly, Red Line Diesel Fuel Catalyst and got regular valve adjustments. My 80 and 84 300SD's got about 25/25 in mixed driving and 27/28 MPG highway. The 87 300TD gets 26/27 MPG in mixed driving and

28/30 highway. As I said, I liked all the diesels but given the choice would pick the 87 6-cylinder as the best all-around engine. (Just make sure the trap oxidizer was replaced under the factory recall - and you get a new exhaust system in the process!)
Reply to
jav

My newly purchased UK spec '95 250D (non turbo) has just covered it's first

300 miles in my hands on 34.58 litres of Diesel.... 38MPG (imperial) or thereabouts????
Reply to
LaoFuZhi

Is anyone here running their diesels on biodiesel?

Thanks

Reply to
DemMan

My girlfriend has been running her 1984 300d on Biodiesel for six months. I just picked up a '79 300sd that I will also be running on B100.

I changed the fuel filters after the first tank, and that is about all I had to do for the change to B100. Smells better, runs smoother, smokes almost not at all. I recommend it!

Plus it keeps the money you spend on fuel, much closer to home, which I really like.

Bernard

Reply to
Bernard Farquart

Actually this is a bit of specious argument. Go look at the fertilizer used to grow the crops for your biodiesel and you will see ammonium nitrate fertilizers derived from imported oil...

Marty

Reply to
Martin Joseph

Are you saying that the same amount of money goes overseas to buy part of the fertilizer?

Or is your argument a bit disingenuous?

I believe self reliance in energy is a vital component of national security that is being completely ignored by the vested interests in power. I feel the need to act as an individual in a way to bring change in our energy policy (at least my own personal policy) I am willing to pay more, for fuel that is not drilled and shipped from places full of those who would do us harm. If there is some amount of oil in the fertilizer that is used to grow the soy, that is used to make the Biodiesel, then it is not a perfect answer, but I think it is *better* by large magnitudes.

Bernard

Reply to
Bernard Farquart

The point he was trying to make, I believe, is that any lessening of reliance on foreign fuel is not happening because the fertilizer could be using the same supply of fuel that you're trying to save, your attempt to feel good about burning less imported fuel is a false savings.

Reply to
127.0.0.1

Biodiesel is nice.... but straight vegetable oil is the best... used one which is free... although it does take a bit of work...

Reply to
Tiger

I lived with a guy who used rape oil for his 190D. He told me he used it a couple of years. The only thing he had to do was cleaning the fuel filter. He also told told me that it made some trouble in winter time. He removed earlier installed special installations for rape oil. He told me, there was no worth for it - just using the diesel engine is the best. But he said, older diesel engines (e.g. the one of W123) might need additional installations (e.g. a preheater).

Right now, there might be a big advantage of using such "fuel"!? BTW, that guy got his rape oil in portions of 50 to 100 litres by a local oil mill.

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Reply to
Roland Rickborn

I find it very unlikely that it takes 100 gal of petroleum in fertilizer to make the soy that is processed into 100 gal of Biodiesel.

It would tend to be *less* in fact alot less, so even if you are using the same supplier, you end up using less.

Unless you think the agriculture industry is so inefficient in this country that the amount of oil used is the same.

I actually meet the guy who makes it, so how does he make any money, or the farmer, or the trucker, if it is a zero gain proposition?

I have never understood the resistance people have to the idea that an easy, profitable, low impact way exists to start to wean ourselves off of what must inevitably end someday relatively soon.

Bernard

Reply to
Bernard Farquart

so much for the 25+ mpg just for getting a diesel + the face that a good diesel will last 300+k miles per engine saving the cost of down time & cost of 2 motors

hell screw the fry oil, if it was meant to run on the stuff Ronald would be driving it.

300SD 260K

the case, minus a few cans!

Reply to
pool man

I have never understood the small mindedness of people that won't look at the whole situation, but want an easy answer.

Like "electric cars" are so great, as long as you don't look at how the electricity is produced. Hydrogen cars are fantastic as long as you don't examine too closely where this hydrogen comes from, and Biodeisel is a panacea as long as you close your mind to the goverment subsidies the deforestation and water usage as well as petroleum derived fertilizers that support it.

That's not to say I think biodeisel is bad, only that it is no great "solution" to our energy problems. it's simply another idea, which has some promise, but must be scrutinised critically and in great detail before we all go bananas for it.

Also, biodeisel is no way "low impact". Think about the cleared land to grow the crops and the water that has to used/moved to make the crops grow, and the fertilizers and pesticides... These are relatively high impact when compared to pumping oil out of the ground.

Sorry to rain on your parade, but ultimately I am afraid that the best real approach we can take to making a difference is conservation, not just a different flavor of fuel.

Marty

Reply to
Martin Joseph

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