Some engines have had the problem of the crankshaft pulley bolt coming loose. This will make a rattling noise as the engine idles. Our technicians tell us that the pulley bolt should have a thread locker applied and then retorqued.Google+
Car Problem Reports
Toyota Tacoma Crankshaft Pulley Bolt May Come Loose
Toyota Tacoma Problem
Engines Affected: 2.4L 4 Cylinder, 3.4L V6
Average Mileage: 114,250 mi (70,000 mi - 187,000 mi)
Visitor, 1996 Toyota Tacoma, 3.4L V6, 83,000 mi
Pulley fell off completely, bolt and washer are gone. It looks like the pin broke.We haven't fixed it yet.
Visitor, 1995 Toyota Tacoma, 2.4L 4 Cylinder, 187,000 mi
Bottom pulley fell off, very cold, approx 5 degrees F., about a mile after leaving home with it.
Visitor, 1997 Toyota Tacoma, 2.4L 4 Cylinder, 70,000 mi
Loss of charging and oil pressure, Both lights came on.