Nov 04, 2023
Time for the new puzzler. This one was inspired by a fan who wrote in with a problem in her minivan. And it just sounded like it would make a great puzzler, so here we go.
She wrote to us, years ago, and said this.
"I recently had a problem with my Chevrolet van. Anytime I stopped the van at a stop light if it was warmed up, the oil light would flicker on and off.
So I checked the oil and discovered I had plenty of oil in there. I'm becoming concerned about this happening, that I might have low oil pressure.
Oh, and by the way, I don't know if this has any bearing on the situation, but I have very little heat as well."
Okay to recap, her oil light flickers on when she comes to a traffic light, and she thinks she has low oil pressure. So, why is her oil light coming on, and what does the heat have to do with it?
Good luck.
So what is happening with this Chevy van, its flickering oil light, and the lack of heat and low oil pressure?
So why does she have low oil pressure, and what does the heat have to do with it?
She did indeed have low oil pressure and that was because the oil was diluted with gasoline. And the key to the thing was in fact the poor heat. The reason her oil was diluted with gasoline was that her engine wasn't reaching the proper operating temperature. And as a result, the coolant temperature sensor, which tells the fuel injectors how much fuel to use, says the engine is cold. This causes what is called a rich condition because the engine is not warm, so it throws extra fuel. And that extra fuel does not get combusted, and it sneaks down past the pistons and ends up in the crank and it dilutes the oil.
And it dilutes it so much that when your engine is idling at very low speed, like it does at a stop light, it is enough to make the oil light flicker on because the oil pressure really is low, because you don't have just oil in the crankcase. You have oil diluted with gasoline.
Love that one.
