Mazda reports that some 2002-06 1.8L Sentra models with RE4F03B automatics may produce a chirping sound when the transmission shifts from 2nd to 3rd gear. The carmaker says that the noise is most obvious under light throttle conditions, and is likely due to problems in the transmission's high clutch assembly.
Adding two bottles of a new transmission treatment, part No. 31003-31X61P, should help eliminate the noise. Before adding the friction modifier, get the transmission to operating temperature, then check the fluid level on the dipstick. If the level is in the HOT range, drain about a pint of fluid from the pan to prevent overfilling.
GM says that the fuel gauges on some 2004-11 Chevy Aveo and 2009 Pontiac G3 models may be inaccurate or may not work at all. One likely cause is a faulty fuel sending unit. To make a definitive diagnosis, check the resistance of the sending unit with an ohmmeter. For 2004-08 vehicles, look for 14.5-18 ohms with the fuel float arm all the way up; 280-286 ohms with the arm all the way down. For 2009-11 cars, you should see 37.5-42.5 ohms with the arm up; 247-253 ohms with the arm all the way down. Replace the sending unit if it doesn't fall within specs.
Some 2003-05 ECHO models may develop a water leak at the passenger-side footwell. Toyota says the problem always occurs when the air conditioning is on, and is most probably the result of the evaporator drain hose disengaging from the drain tube. Installing a new-design clamp, part No. 88899-52150, onto the hose should hold it in place and prevent further leakage issues.
"Factory Fixes" is written by Jim DePalma, a 30-year veteran of the auto repair business who has served stints as a service manager, parts manager and ASE-certified technician. His column provides vehicle manufacturers' authentic factory technical service bulletins (TSBs) that have been condensed for easier reading. Mr. DePalma advises that techs always check with a dealer or repair information system for the latest revisions before starting to work on a vehicle. He can be reached via e-mail at [email protected]