Indica Engine Oil Issue

Wohnort:
New york

Hi,

I own a 2005 Model indica dls bsII. I have changed oil when odometer reached 35000 , now it turned black and thickened on 38600.After running just 3600 kms. Is this a problem with indica? Shall i need to change oil now.? Or can i go for any engine oil treatment/additive ?

Any idea?

Please help.
Thanks!

I didn't find the right solution from the Internet.

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