The Oil Light

This is a real-life puzzle. We had a fella that came into the shop with an 85 or an 86 Dodge Caravan as luck would have it, with a 2.2. engine. The smallest engine that they make. And he had a bad camshaft and his mechanic had put a new one in there because this other camshaft was made out first.

So instead of having clack, clack, clack, clack, clack, clack, clack, clack, clack from a worn out camshaft, he had a relatively quiet engine. He replaced the camshaft and all of the hydraulic lifters and the rockers rather. Okay, so he had this new camshaft in there, and everything was great. Except that he had a little problem. The oil light was on all the time. So he went back to the mechanic and the mechanic checks the oil pressure and says, "You don't have enough oil pressure. That's why your oil light is on." So he said, "How did that happen?"

Because the oil light had not been on prior. So he said, "Okay, what do I need now? Another 300 bucks for a new oil pump?" And the mechanic says, "Yeah. Debris from the old camshaft must have gotten in there and chewed up the old pump."

And as you might suspect, he did the oil pump did do the oil. So the light didn't remain on, but an interesting thing happened. The light no longer came on ever, even when he turned the key on the on position. But what he didn't notice is that the engine was racing all the time. Oh, that's when he took the car to us, the court of last resort. We had the car for a month and we indeed verify that he had low oil pressure. But interestingly, the light was not on.

Well, we found the light was not going on because it was unplugged. Oh, so we plugged it back in. And lo and behold, the light came on.

The question is what's going on here? The hint is what's going there's nothing wrong with the rest of the motor. The engine is fine. At least, all the parts that could cause oil pressure, are all fine. But! Something else went awry on this job. So what is it?

Now, this is not an easy puzzle. This is tricky. It has to be tricky, because, yeah, we didn't figure it out for a month.

Answer the Puzzler »

Remember last week's puzzler?

The Sparking Tankers

It's time for the new puzzler. You're ready. You probably know I have an interesting puzzler. What's more interesting is that we're not sure of the answer, but we will have it.

I remember when I was but a wee lad, going for Sunday drives anywhere in Our Fair City that we would see large tanker trucks loaded with flammable or inflammable fluids.

And they all had somewhere, attached to the underpinnings of this thing from the carriage, a chain or some metal conductive contraption that went from the frame of the vehicle and touched the ground. And it would throw off a shower of sparks as this chain dragged along the ground when the vehicle was in motion.

The question is, part one: what are those big trucks that have these things?

And part B, I will preface the question with the statement that I see these trucks nowadays, but I don't see the chain. So part B is how do they make invisible chains?

Or Part B is, why don't they have them anymore? They used to have them, why? That's part one. And part B, they don't have them anymore. Why?