Mike, Scapoose, OR

On this week’s show, Mike called with a noise that he described as a bowling ball sound from his trunk when he came out of a stop. C&C went to the tranny, but an obvious thought occurred to me that could have been overlooked.

Often when a car is converted to biodiesel (as this was), an auxiluray fuel tank is put in the trunk, often in the spare tire well, complete with a coolant line running through it to heat the fuel so it will burn more easily. If this is in fact the case, seeing as how the problem was described as like a bowling ball in the trunk, the first thing would be to make sure that any such tank is 100% solid, with no sliding or rocking possible.