From the previous posts, I found two liqui moly products.
One is "Engine Flush"
Other one is "Ceratec".
For older cars (like I have), its good to use engine flush first. And after that use ceratec liquid.
Engine flush will remove all oil related impurities. And Ceratec will coat a thin film of chemical inside the engine which is good for 100K and this will also keep pushing back the incoming impurities.
Will it be good to use above chemicals instead of pouring disel engine oil ?
Advise of experts would be v. helpful.