Q I have a '93 Pontiac Grand Am with the 3300 six-cylinder engine. The temperature gauge doesn't work, which is a problem because the car has a history of overheating. Any tips on how to get the gauge working, or install a new one?
A Is it the gauge or the temperature sending unit? The easy way to find out is to unplug the temperature sending unit harness, located under the alternator near the front of the engine on the passenger side of the engine compartment. The forward-most connector is for the coolant sensor that supplies a signal to the engine management system. It's the rear connector you're looking for -- this one is for the temperature sender for the gauge. With the connector unplugged, use a short jumper to ground the "A" terminal of the connector. Turn the ignition switch to "run." If the gauge moves to "hot," replace the sending unit. If it stays "cold," check the instrument and its circuit.
Q My mom and I both have 1997 Toyota RAV4s, and we both had timing belts replaced at 65,000 miles as preventive maintenance. Both RAV4s now have 118,000 miles. When do you recommend we replace the timing belts again? We both plan on driving our RAV4s for many more miles. Any other preventive maintenance we should be doing?
A The timing belt service interval recommendations from Toyota say: "On 1997 and prior models, under normal service conditions, manufacturer does not recommend a specific maintenance interval. On 1997 and prior models, for vehicles operated under conditions of excessive idling and/or low-speed driving for long distances, replace at 60,000-mile intervals. On 1998 and later models, replace every 90,000 miles or 72 months."
Leaves you and your mom in a gray area, doesn't it? Unless both of your driving patterns fit the "severe service" described above, I don't see a need to replace the timing belt until at least 150,000 miles. To ease your concerns, have the timing belt visually inspected at about 120,000 miles to check for evidence of oil, cracking or deterioration.
Toyota's "normal service" recommendations at 120,000 miles include changing engine oil and filter, air filter, coolant, spark plugs, and the differential oil in limited-slip differentials.
Q I have a 2001 GMC Sierra 1500 4x4 pickup with the 5.3-liter engine. When it gets below 10 degrees the engine starts with a surge, then dies, and even though the engine turns over, it won't start. When the weather warms up, it starts like a charm. I am worried about the same problem this winter. The GMC dealer says he can't diagnose the problem if it doesn't present itself, and he needs to look at it when I'm having trouble starting the engine. But I want to be proactive and fix the problem now. Any suggestions?
A The fire/die followed by a no-start sounds like a fuel-pump issue. While someone is behind the wheel engaging the starter and cranking the engine, pound on the bottom of the fuel tank with a rubber mallet. If the truck starts, the fuel pump is failing. If it doesn't, check by feel to see if the fuel-pump relay is engaging. Or try another relay with the same part number.
