I need to positively identify my tractor!

[Looking4new]

You could send a sample of the oil out for testing. The results that come back will tell you what all is in the oil.

[saracenas]

It might also be, that the rings could stick to the pistons in case if an engine has had many cold starts and stops within the sales phase without normal warming-up. In that case needs to work hard for a while with max loads to clean up the rings. The usual thing of big engines is - they love workloads. Check also engine breathing system (pipe from the valve cover to the atmosphere) for behavior of gas/steam stream.

To answer your question I would say 'yes' and 'no'. Yes, means it is good that the engine flushes itself of the deposits. No, when it means an engine has excessive wear of cylinders/rings, and the oil is being mixed with exhaust gases.

In your case I would start from hard working/loading first taking under special control oil level. If an engine isn't worn-out, just sticked the rings, it could "eat" some oil at the beginning, but will stop "eating" it later. The oil still could be black, but after the oil change it may be (again after 50 h or more), well, not completely clear, but about semi dark compariing to what you have now.

But if an engine is worn out, it "eats" (and not stops "eating") oil then nothing will help, except reman.

[saracenas]

Ah yes, about noise. Some older engines make "metal" noise when just started. That noise should disappear right after warming-up phase has ended. That's normal.
You may also hear costant, a bit hammering "metal", but not terrible, noise from the upper part of engine. It could be valves, which need to be adjusted.
There's no recipe for all the noises, but just listen to all abnormal appearances from that point of view. In case of any suspicion, talk to local dealer or well experienced guy. Or indeed TBN.

[D7E]

If the engine oil is getting as dirty as you say and bearing in mind we do not know the tractor history , it might be useful to try one of the industry flushing oils through it to clean it up or even dilute oil with 50% diesel and run on that for a couple of hours (no hard work) the diesel flush can work wonders at cleaning up an old dirty engine !!

It is quite normal for old high houred tractors to black the oil in a few days work but yes flushing with diesel is very common and i have done it to a few but it has to be bad for me to do it .

[PierreR]

I can't thank you all enough for these fantastic advise! So much experience here! Thanks for all the hints !

I`ll flush with the diesel mix you guys mention. Then I`ll see if I need to go deeper.

I don't hear noises like you describe Saracenas, just a smooth diesel sound, much like in the old "Thunderbirds" programs of my young years... but I`ll keep listening.

Being at it, I have one more question: when I saw oil coming out of the steering column, it looked gray, not much like the clear oil that goes in... would that be water mixed with the oil?

I hope I can help you guys in turn when I can!

PierreR

[cyrush]

The gray looking oil sounds like there may be sone air in the oil, possibly through cavitation on the steering pump circuit. air will eventually rise out of the oil with the machine at rest!!

Or it could be water mixed in the oil, which has emulsified and turned the oil a whitish gray !!

[tcreeley]

I knew somebody who used kerosene in his gas engine instead of oil, for 3 min to clean it. He killed his engine. Just change the oil a bunch of times. Use a commercial product if you have to- but I wouldn't. May not run after.

[PierreR]

Hummm... now that's a red flag! it must indeed be safer to just change the oil many times over... rince, repeat

[JD 4520]

Being at it, I have one more question: when I saw oil coming out of the steering column, it looked gray, not much like the clear oil that goes in... would that be water mixed with the oil?

PierreR

Definitely moisture, it may be water or heavy condensation. If its worth it to you I would change the oil and then you will know what you are working with from there. If it returns you will have more info, if it doesn't return you will know why.

[saracenas]

I knew somebody who used kerosene in his gas engine instead of oil, for 3 min to clean it. He killed his engine. Just change the oil a bunch of times. Use a commercial product if you have to- but I wouldn't. May not run after.

I second this point. You might have very bad consequences while flushing an engine with either fuel mixed in oil. I don't like any commercial flushers too although they are available in the market and it's quite safe to use them. Oil not only lubricates, but also flushes engine in the best way. Black deposits in the oil prove that.

Hummm... now that's a red flag! it must indeed be safer to just change the oil many times over... rince, repeat

Change the oil (you've done it) and try to load an engine while working with a machine for a few tens of hours. And just look what's going on.
Very good point is that you have smooth engine sound from the beginning.
BTW which one(s) Thunderbird(s) have you owned? I never had one, but loved those of 10th generation.