a year ago I bought a Ford Focus 2006 1.8tdci diesel engine with 112.000miles on it and engine oil light comes on every cold start and it stays on about 4 secs and then goes away. When engine is hot and has been driven already oil light disappears as soon as car starts but as said when engine is cold it stays on for about 3-4 seconds and then goes away , is that something to worry about? Car runs just fine oil and filters changed on time
well if the light is correct (test with gauge), then yes I would fix the problem asap. You don't want the engine to be starved of oil when cold starting.
Maybe the oil pickup is blocked or came loose. An oil drain channel is blocked, or the pump is worn out ...
many possibilities
could just be the engine is just worn out. It's not uncommon for the junk Ford produces. The dealership typically fixes it by dumping in additive. (it only makes the light go away. not fix the issue)
Measure the oil pressure and compare it with the specs.
You could be using the wrong weight oil or an oil additive that's too thick. See your owner's manual for the correct weight oil for the ambient temperature you're operating in.
