Replacing 15W40 with syn 5W40 issues on old/high hour engine?

[Wolfy]

One of my tractors is a 1977 Ford 1600 diesel. It was a DPW mower and has about 3,700 hours on it. Every time I check/change the engine oil, it is black as licorice. I just did an oil change with Valvoline Premium Blue 15W40 and a Napa Gold filter. Within like 45 seconds, the new oil was as black as the old. So I was wondering, has anyone had luck changing oil to synthetic on an old engine like this? With the high hours, and it does have some blowby. I know it would start easier in the cold, and I've heard after a few oil changes, the syn will "de-sludge" the internals?

 

[murphy1244]

I am by far an oil expert but I believe that is normal soot removal.

 

[Wolfy]

You might be right. Our construction equipment engines also have black oil.

 

[Gary Fowler]

If you are prepping for a cold winter and intend to use the tractor a lot, synthetic 5W-40 will aid your starting by being a lot thinner. Your old tractor might use a bit more of it between changes though so keep that in mind if you go for the synthetic.
As for black oil, all diesels have black oil within minutes because the high detergents in the diesel rated oil keep the carbon deposits in suspension. If you have been using diesel rated oil all the time, I doubt there is any sludge to clean up. Black oil is a good indication that your HD oil is doing its job.

 

[Wolfy]

Thanks Gary, that eases my mind. You and Murph are saying the same thing, and it sounds logical to me. Yes I only use diesel rated oil. Besides starting better in the cold, I could see the synthetic running cooler in the summer, esp since I mainly mow with the 1600.

 

[Gale Hawkins]

One of my tractors is a 1977 Ford 1600 diesel. It was a DPW mower and has about 3,700 hours on it. Every time I check/change the engine oil, it is black as licorice. I just did an oil change with Valvoline Premium Blue 15W40 and a Napa Gold filter. Within like 45 seconds, the new oil was as black as the old. So I was wondering, has anyone had luck changing oil to synthetic on an old engine like this? With the high hours, and it does have some blowby. I know it would start easier in the cold, and I've heard after a few oil changes, the syn will "de-sludge" the internals?

Wolfy we went to 5W-40 Rotella T6 Synthetic and after the first oil change the oil seems to be less black but black is normal for diesels. We wanted ease of start. One is a 1976 265 MF and the other diesel is a very very worn 1983 JD 310B back hoe and it does not use much oil and NO more than when it was running dino.

Our Archoil AR 6200 fuel additive and Archoil AR9100 oil additive come this past week and will see if it helps clean up the gas and diesel engines as it claims.

I think all oils today are super. We went with Rotella T6 because it is rated for all of our gas engines as well as the latest diesel specs.

 

[Wolfy]

Thanks Gale. I agree that we have very good oils today. I have not used synthetic Rotella, but I have used regular Rotella, and have no issues with it. About every parts store near me stocks it.

 

[Diamondpilot]

With that many hours I don't see pee say with going to synthetic oil but I can see it finding some new leaks by removing sludge in gasket areas.

Chris

 

[Jay4200]

One of my tractors is a 1977 Ford 1600 diesel. It was a DPW mower and has about 3,700 hours on it. Every time I check/change the engine oil, it is black as licorice. I just did an oil change with Valvoline Premium Blue 15W40 and a Napa Gold filter. Within like 45 seconds, the new oil was as black as the old. So I was wondering, has anyone had luck changing oil to synthetic on an old engine like this? With the high hours, and it does have some blowby. I know it would start easier in the cold, and I've heard after a few oil changes, the syn will "de-sludge" the internals?

The oil turning black means it is doing what it is supposed to do, which is hold contaminants in suspension. You could always do an engine flush if you thing there is sludge in there - put in 3/4 cheap oil and 1/4 kerosene. Idle the engine for 5 minutes, then dump the oil/kero. That should clean it out. Also, 5W40 and 15W40 are the same operational viscosity (once hot) - the only difference is at start-up, where the 5W is thinner and flows easier when cold.

 

[Wolfy]

Thanks for the replies Diamondpilot and Jay4200. A big part of the thought to go with synthetic is for winter plowing, although, it starts decent on the 15W40. I was doing some math and it might be cost effective to go with the synthetic. The owner's manual says to change the oil every 100 hours. I would think with synthetic I could bump that to 200 hours. Probably would not save much oil wise, but that would be one less oil filter.