Some 1998 Ford Crown Victoria, Mercury Grand Marquis and Lincoln Town Car models may deliver less-than-adequate air conditioning performance, often accompanied by a thumping noise whenever the compressor clutch engages.
Both symptoms causing the problems are most likely the result of an overactive clutch cycling switch due to the switch's location, according to Ford.
To make a definitive diagnosis, hook up your pressure gauges, then start the engine and turn the a/c controls to MAX. If the clutch switch cycles off at a pressure higher than 24 psi or you hear the thumping noise every time the compressor engages, the switch needs to be repositioned. To do it, you'll have to install a revised accumulator, part #F8AZ-19C836-AA and suction hose, part #F8VZ-19867-BA.
An owner of a 2000-04 Saab 9-5 model may come to your service desk with a complaint that the engine won't always crank over when the ignition key is turned.
One possible cause for the intermittent no-crank problem, Saab reported, is a loose retaining nut at the positive starter terminal. The loose nut causes oxidation to form at the starter connection. That, in turn, leads to poor electrical contact, causing the intermittent no-crank issue.
Start the fix by removing both battery cables. Next, remove the positive cable retaining nut and cable from the starter. Using a stiff wire brush and penetrating oil, thoroughly clean the positive terminal on the starter, the retaining nut and the positive cable lug.
Now reinstall the cable and retaining nut and torque the nut to 7 foot-pounds. To complete the repair, reconnect the battery cables and check for proper starter motor engagement.
Toyota said 1996-2000 4Runner trucks are susceptible to vibration problems while braking at speeds above 40 mph. Excess thickness variation in the front rotors is the most likely cause.
To get rid of the shimmy permanently, the Japanese vehicle maker recommends turning the rotors with an on-car brake lathe, then installing newly designed front brake pads, part #04465-35240, that are easier on the rotor surfaces. The old pad shims can be reused unless they show signs of heat discoloration. If they do, also install a new shim kit, part #04945-35040.
“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. He can be reached via e-mail at [email protected]