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I've roughly calculated the miles per gallon I get with my 1980 300D and it comes out to around 12-14 MPG each time (city driving). I know that's really poor, but other than that the car seems to be in great shape (130,000 miles). All filters have been replaced and I've added additives in the fuel tank, and I've run Lubro-Moly Diesel Purge directly through the injection system, and it still performs the same.

I've heard that the injectors need to be replaced at 100,000 miles, so I'm wondering if that is the problem. Also, just recently the fuel line that runs from injector to injector (one of them nearer to the firewall) which has braided cloth over it, seems to be wet with fuel. Any ideas?
 

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82 300D, ISU Formula
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Those braided fuel lines can be a real PITA

I know mine were popping off and leaking while i was driving. I guess all you can do is run the car and look for the leaks. Maybe replace those lines. Also check for a leak in the canister fuel filter. Sometimes those leak just after replacement.
 

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fuel and oil consumption are related. numerous Italian
tuneups will help. City driving ca...


fuel and oil consumption are related. numerous Italian
tuneups will help. City driving can sludge rings causing high fuel consumption high oil consumption.
Have a 130K parts car this happened to before I bought it. PO forgot to add oil, and toasted engine.
It is a 77 300D.

To stop and reverse the sludging, leave it in "2" so it does not get out of 3rd in the city. Poor fuel economy will comtaminate the oil causing a vicious cycle.

I have taken old sludged diesels from 200 miles per quart to 600 and 800 miles per quart. I have put 2 bottles of CD2, then changed oil at 1000 miles. CD 2 is kersonsene based but does not describe it as that on the bottle. Some people have put 50% kerosene on the engine and idled it for 30 minutes. Then changed the oil. Very risky, it can work just great after one or two tries. Or you WILL BE CHANGING THE ENGINE. Because all the garbage has came loose at once, or the pistons never seal again.

The CD2 is slower and safer. Many people bite the bullet and switch to Mobil 1 15-50. Expensive in an oil burning engine. But it can reach a stable point at much higher mpg and less oil consumption.

If you want the safest route, slow, can take 5 to 20K miles. Some even report improvements up to 50K Mobil 1
15-50 is the quality safe way to desludge an engine aling with plenty of beating it.
John Gregg
 

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83 300TD/97 E320/98 SL500
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Everything you ever wanted to know

about motor oil:
http://theoildrop.server101.com/cgi/ultimatebb.cgi

Several types of additives are discueed that safely dissolve sludge/deposits and loosen rings are discussed.
 
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