Hi, i have a tdi ( 1.4 pd) with 123.580 kilometers, at that mileage is it preferable to flush the engine with a detergent before oil change or is it a meaningless activity for the engine. What's your opinion ? .
Take it for a drive and get it up to temperature. Drain the oil, don’t burn yourself! Leave it until it stops dripping. It will then be as clean as it needs to be.