Possibly this car is mixing either oil with water or diesel fuel

I tend to agree that there are some red flags. Will they allow you to do a couple tests? The smoke from the crank case is not alarming by itself as it is a diesel and they tend to do that.

However, the picture of the coolant appears to be fine as it looks clean and red. The oil cap appears to have something on it which would give me pause. However, if we can do two tests that will put all this to rest. First is a head gasket test. Here is a guide for that:

https://youtu.be/5zpNjYmmiYY

If you use the chemical to detect hydrocarbons then that will work for diesels as well.

Also a compression test. It sounds ok but we need to just confirm that you don't have one cylinder lower which would point to the issue.

https://www.2carpros.com/articles/how-to-test-engine-compression

If those two check out then I would not be too concerned. Let me know if I am not seeing something in the pictures that you are concerned with. Thanks

Hello, thank you very much for your reply. Unfortunately i do not have the resources to do neither tests! About the oil cap, i checked it while the engine was cold and it had absolutely nothing but then after about a 30 minute test drive the engine was warmed up, only then this appeared as shown in the photos. Were you able to notice the diesel fuel all over the engine? it's a bit difficult to notice on the picture!

Interesting. Unless you are getting a good deal on it and without running those tests, I would pass. If it was not there before and the smoke started after it got hot. Then I would think it has a head gasket issue. I did not see the fuel on the engine but that is just another red flag. Again, if the price is right this is not anything that can't be fixed but I would not pay full price.

Let me know what questions you have.

Thank you for your help! Your knowledge is helping me a lot on my decision! Wish you all the best!