Synthetic oil
 

My 84300td now has 81K on it would it be a good idea to start running synthetic oil in her? Could this cause her to start leaking oil?

Mrhaney

Synthetic oils per say don't really cause oil leakage. However, if you have sludge that is holding the oil in the system and the syn oil cleans it off, you might have a leak then. In any case, I don't think you need to bother with syn unless you are trying to extend your oil changes or you are running really hot on your turbo. That was why I switched to syn.

Use the syn man,

Mobile 1 15w-50 baby yeah!

or at least Mobile Delco 1300 all good stuff

I did notice a few more leaks ( I think) than I had before, after I switched to synthetic. Of course its 0w-40 mobil 1, I plan on going to 15w50 soon.

If I was told right, the "W" in 5W-40, or 10W-30, does not mean weight. It stands for "Winter"

In Canada during winter months for example, the use of a low viscosity oil such as 0W-30, or 5W-40 would be recommended. Too thin of an oil in older engines I am told will increase bearing wear.

Recently, I stated that I was switching to a 5W-40 Rotella T synthetic, then I read about what I've just mentioned above......Anyone in Canada want to buy 8 quarts of Rotella T synthetic cheap?

I'll stick with the Mobil One 15W-50.................. :rolleyes: BB

Naw, you just about got that engine broken in. Synthetic is recommended in VERY cold weather but pretty much considered a waste in the 123 diesels, unless you just want to baby them :D

I was just looking at an '81 300D with only 76K miles on it (actual miles!)
Sheesh! low mileage cars like that make me envious!

1971 220 (gas) 4-spd manual 106441
1979 300TD w/ ’85 turbo engine 296650
1983 300D 243280
1985 300TD 223470
1987 300D 262300

A 10W30 oil is a 10-weight oil that will not thin more than a 30-weight oil when it gets hot. http://www.chris-longhurst.com/carbibles/index.html?menu.html&engineoil_bible.html

An oil sold as 10w-40 is no thicker than 10 weight oil under Winter (10w) conditions, meaning below freezing. The 40 means it is no thinner than 40 weight oil at 212° Fahrenheit. So, the first number tells us the performance of the oil at or below the temperature of freezing water, and the second number tells us the performance at the temperature of boiling water. The chemicals added to the oil to accomplish this are called Viscosity Index Improvers (VIIs).
http://motorcycleinfo.calsci.com/Oils1.html