Larry,

A little oil sure will not hurt....
The 'ounce of prevention....' so to speak.

I've been using Citgo and BP diesel for over 10 years in my diesel farm equipment and for the past 5+ years in my MB diesel engines. I have never had a probem.... yet!

I, too will be tossing in my ounce of prevention on each fill-up.... because you can never be too careful when it comes to our multi-hundred dollar pumps...

PS. You're welcome

------------------
William
76 240D (W115) - 550K miles
78 300D (W123) - 200K+ miles

Ah, yes, now I have something new to worry about... I've read on alt.auto.mercedes that some people who added ATF to their tanks had problems with clogged injectors. Also the red dye can make it look like you're using red dyed off-road diesel.

I stopped using Redline DFC a couple tanks ago, but now I'm thinking it might be cheap insurance against problems with my injector pump. At least it is designed to be added to diesel fuel, and I almost think I've noticed improved driveability with it.

Another thought, I know there are some chemistry gurus out there; can I dissolve powdered sulfur in diesel fuel and would this restore the lost lubricity? How much would have to be added?

------------------
Robert W. Roe
1984 300SD 172K mi

To Jay:
The cam of the injection pump and its bearings (the lower section of the pump) are lubricated by the engine oil. It is the barrells and plungers (upper section of the pump) that are lubricated by the fuel oil. It is in the upper area where the sulphur helps to lubricate the barrel and plungers.
P E H

Robert,

ATF would probably not be the best choice for this. I believe that ATF began being used by us shade tree type guys many years ago in crankcases, because of the increased cleaning capabilities. For this reason, people have, over the years, thought of it as an additive for what ails you(r car).

Good clean, cheap engine oil is a better choice for this, and it takes very little to get the job done. I believe that ATF brings nothing additionally necessary into this. All you need is just a touch of OIL.

William,

Actually in my diesel farm equipment, I haven't been as dilligent in adding oil to the fuel and have had no problems. I don't know if the low sulpher restrictions hit the farm fuel at the same time or not. I hope I never find this out the hard way.

Good luck,

------------------
Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

look here for GOV. info
http://www.ott.doe.gov/decse/

All of these governmetn bozo's pie in the sky theory's do not take into account reality. Reality involves people being forced to add lubricants, which as a net effect add more sulpher than if the government had left well enough, alone. The people adding the lubricants are doing it to protect their pumps.

We're talking about the poor people who have older cars that cannot handle the lack of sulpher (lubricant).

The net effect is more pollution in the air than if our government in their infinite wisdom had left it alone in the first place.

Albert Einstein once said "Elegance is for tailors, don't always believe in something because it's a beautiful mathematical formula".

My $0.02,
Larry

Larry, you've sold me on the "ounce of prevention" concept with adding oil. Tonight I bought a quart of Chevron Delo 15W40 at Walmart, and poured about 2 oz in before refueling.

I wonder, is it better to add it before or after adding fuel? I always added Redline or Techron before filling the tank, and I figure the fuel going into the tank will maybe wash some of the oil down off the filler neck.

Does this sound right? Or should I add the oil after the pump stops, since I don't top it after the first time the pump shuts off?

I resisted the 74 cent/quart 30W non-detergent, figuring if my car ever needs oil, I'd have the right stuff to top off the crankcase. I wonder, though, if the additional thickeners in the 15W40 might be bad. Or, should I get some synthetic single vis stuff? I know, many questions.

Results? Too early to tell, I know, but I did notice a bit of smoking on the way home. But then again, my car has always smoked a bit, anyway. I just hope that the oil I added didn't mix with only the last 3 gallons of diesel fuel on the bottom of the tank. The car seemed to idle a bit quieter and smoother, but this could definitely be my imagination.

This wouldn't improve throttle response, as in lubricating the throttle linkage, should it?

I do remember seeing a price of like $999.99 in the Impco catalog for a rebuilt injection pump, so this does seem like cheap insurance.

Thanks again for the advice.

------------------
Robert W. Roe
1984 300SD 173K mi

Robert,

This is not a critical operation involving specific ingredients. Just dump in a little oil then fill it up. The inrushing fuel should mix the oil reasonably well. If you don't put it in before fueling, it will eventually mix anyway.

This is the kind of thing that will not show up in performance, feel or anything, but it should protect your injection pump for the long term.

Good luck,

------------------
Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Would this cheap oil insurance be advised for a 92' 300D 2.5 turbo?

Or a 1991 300D 2.5 for that matter??

Just a general question in regards to MB diesels that may or may not be applicable to this topic. Do any of the MB's diesels have cat converters on them? My 300SDL has two mufflers or one muffler and a cat converter. Not really sure ,but I figured some one on the forum would know for sure. The reason I posed the question, other than to determine mufflers or cat on my car is that if by chance MB is currently or previously putting cat's on their cars then it would be advisable to add only oil with low ash content. High ash content is not a good thing for cat converters.

Thanks for the advice on adding oil. I think it is a good thing to do, for peace of mind and your wallet as well.

I have never added oil to diesel fuel in a vehicle within any sort of catalytic converter. I would do a lot of research before I did so. I think if the car is that new, it probably has the hardened barrels due to the decrease in sulpher content in diesel fuel in Europe at about the same time.

Good luck,

------------------
Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

O.K., stupid question, but how are you getting oil out of a bottle into your filler neck without it ending up running all over the place? Or do you actually have a little oil can squirter or funnel in the trunk?

Greg

I bought a quart bottle of oil, and even when full it was easy to get it up to the filler neck without spilling a drop. I do carry a funnel, but it's in a ziploc bag and I only use it to top off transmission fluid.

It probably seems a strange place to put this warning, but it is very important. The ATF funnel in the bag reminded me.

DO NOT USE THE SAME PLASTIC FUNNEL FOR FILLING THE TRANSMISSION THAT YOU USE FOR ANTIFREEZE!!!

Even the tiniest traces of antifreeze can destroy the clutches in an automatic transmission. You can not adequately clean the antifreeze from a plastic funnel.

Don't think that you can adequately clean the antifreeze from a funnel. If a plastic funnel is used for antifreeze, consider it CONTAMINATED as far as automatic transmission filling is concerned.

This is not a joke. Your automatic transmission is much too expensive to take this chance. Be careful.

Good luck,

------------------
Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, manual, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles