Join the Car Talk Community!

Pump Down the Mileage

The Puzzler


RAY: We did, by putting in the new pump, make his mileage drop. We missed something. We missed something. What we missed is that there is a piece of tubing that goes between the tank pump and the main pump, and it had a little pinhole in it.

TOM: So the little pump inside the gas tank pumps fuel along this tube into the main pump. The main pump then pushes it the rest of the way to the engine.

RAY: Now with the intake pump broken, this little pinhole did not cause gasoline to leak out because there was suction created in that tube. When we replaced the feeder pump, we created positive pressure in that line between the two pumps. Even though most of it was being sent to the injectors, just enough was leaking out through this little pinhole to cause this 12-point-7-5 percent drop in mileage. So he was right, even though we didn't do anything wrong.

TOM: I mean that's an interesting...what if that were a -- this brings up an issue, a legal issue. What if this were a life threatening thing.

RAY: What if his car had burst...

TOM: What if it burst into flames and he died? Then he wouldn't be able to see. Well, what if he didn't quite die, unfortunately.

RAY: Burned beyond recognition?

TOM: Burned beyond recognition.

RAY: But his memory was intact, and he could call his lawyer.

TOM: He still had enough energy left to call his lawyer, right. The thing is are you required then to look to see that there are no little pinholes, which could never, ever happen except once in a while because you would install the pump, you get in the car, you turn the car, the thing would run like a dream, and you'd say it's running like a dream, everything is fine.

RAY: Yeah, we never saw the pinhole because it was pointing up and spraying gasoline on the under side of his car.

TOM: Sure, and you wouldn't even see it.

RAY: Right near that hot exhaust system.

TOM: You wouldn't see it. Interesting.

RAY: Interesting.

TOM: Yeah.

RAY: Yeah, whose responsibility is it? Ours.

TOM: It is.

RAY: It is, unfortunately.

TOM: I don't think so.

RAY: Well, the judge thought so. Anyway, who's our winner?

TOM: The winner is James Nofi, N-o-f-i, from Flushing, New York.

[ Car Talk Puzzler ]

Support for Car Talk is provided by:

Donate Your Car,
Support Your NPR Station

...and get a tax break!

Get Started

Find a Mechanic


Go



Submit


Rocket Fuel