If you don't see any coolant leaks, suspect a leaking cylinder head gasket. Your mechanic can do a chemical test at the radiator to verify that, or you can add a small bottle of dark purple dye to the coolant. After a day or two search with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. If you see it inside the tail pipe, a head gasket is leaking. Many auto parts stores that sell the dye also have the black light to rent or borrow.
If the speedometer always stays at or below "0", look for a little stop peg and the pointer is on the wrong side of it. There's three ways to reset that. The easiest is to simply drive faster than half the maximum speed on the speedometer. This is no longer a spring-loaded pointer that goes back to "0" on its own. It is pulsed electronically to various positions by the computer in the instrument cluster. Sometimes a glitch, especially when reconnecting the battery, will send the pointer all the way around. From there it only looks for the shortest way back to "0" and that may be the wrong way, then it gets stuck under that stop pin. Once you drive fast enough, the pointer will go counter-clockwise when that is the shortest way to the actual speed. From there it will follow the car speed back down to "0" like normal.
Saturday, September 7th, 2013 AT 9:43 PM