Audi said some 1998-2001 2.8-liter A4 and A6 models can produce a lower-than-normal or “lumpy” idle.
Dirt or carbon deposits on the throttle plate and/or bore are the likely culprits.
To make a definitive diagnosis, remove the intake boot from the throttle valve control housing and take a good look at the throttle plate and bore. Lightly coated surfaces can be cleaned with a soft, dry shop towel. For caked-on or oily deposits, Audi recommended soaking a cloth with a strong combustion chamber cleaner (Wynn's X-Tend or equivalent) and thoroughly scrubbing the plate and bore surfaces.
Once you get everything clean, you'll have to send the car to an Audi dealer to perform a throttle valve control module “relearn” procedure.
Some 2002-04 Ford Explorers and Mercury Mountaineers, as well as 2003-04 Lincoln Aviators, may turn on the ABS light and store trouble codes C1235, C1236 and/or C1237 in the ABS module, Ford Motor Co. said.
According to the car maker, all of the above codes signify problems with the differential-mounted rear ABS sensor—either glitches in its signal or a complete output failure. Regardless of which problem you encounter, replacing the sensor with a revised unit, part #4L2Z-9E731-AA, should prevent further troubles.
General Motors Corp. reported it now has a universal PAG oil for use with all of its R-134a air conditioning compressors.
The new oil, part #12378526, is backwards compatible with all prior oils used in GM R-134a systems, and comes in convenient 8-ounce cartridges for easy injection into the system. The cartridges come packed six to a case.
Some 2001 Lexus IS300 models may form condensation at the bottom portion of one or both headlight assemblies, the car maker said.
Installing new-design headlamps (part #81110-53040, right-side; part #81150-53040, left-side) and sealing off the hole(s) at the top of the fender panel with a special self-adhesive tape, part #90950-06073, should eliminate the problem immediately.
“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]