Ever wondered why diesel oil turns black soon after servicing your engine? Have you in any way accused your mechanic of lying because you thought he never changed the oil as claimed? In this article, we will focus on why diesel oil turns black after service.
Reasons Diesel Oil turn black after service
Few reasons why diesel oil turns black after service include heat cycle, soot resulting from incomplete combustion, presence of amorphous carbon, trapped black oil, and oil change blunders by mechanics.
But for a few reasons, it is not outrightly abnormal for your diesel engine oil to turn black almost immediately after service. Without further ado, let us get started.
First, let us talk about the heat cycle. By heat cycle, I mean the occasional exposure of your car engine to periods of high heat whenever you drive around. For example, during a typical driving cycle, your engine reaches standard heating temperature, and in the process, colouration oil becomes inevitable.
Another cause of diesel oil turning black is soot contamination. This type of contamination is almost inevitable because no technology is always perfect. Soot is a by-product of incomplete combustion that usually gets into the engine through the combustion chamber due to the gap in the piston rings. Also, it takes very little soot to turn the oil into inky black diesel.
Another reason your oil may turn black after service is if trapped black oil mixes with the new one. If you fail to drain the old oil fully, it will pollute the new one within minutes after an oil change.
Also, blunders from your mechanic may lead to diesel oil colouration. If a mechanic carelessly or intentionally tops up the contaminated oil instead of draining it, your new oil will surely turn black.
Another reason why your oil turns back almost immediately after service is a dirty engine. To correct this, make sure the black oil is drained properly before pouring in the new one.
Also, the kilometre (s) your vehicle travels determine how much buildup of carbon your engine will have especially, the old ones. However, a new one will still maintain the golden engine oil colour for some time before turning black which shows that the oil is okay.