1992 toyota previa. When I turn on my headlights at night, only the parking lights come on but it will indicate that my brights are on. What are the possibilities for what could be causing this?

SOURCE: 1992 Toyota Previa van,Oil dripping onto exhaust manifold, replace head gasket? need a free manual!

The toyota previa uses a formed silicone gasket for the valve cover and the cover is held in place by metric shoulder bolts ( 10mm). The valve gasket leaks because you can't get enough preload on the bolts to re-seat the old gasket when it gets old and shrinks. The shoulder bolts only allow you to tighten the gasket enough to seat the shoulder on the bolt. If you continue to torque down the suspected bolts, you will snap the bolt off ( don't ask me how I know this ). You can either 1.)replace the old gasket with a new one or 2.) remove the existing bolts around the leak area and put in new metric bolts that do not have a shoulder. You may want to put in a small sleeve into the existing bolt hole but shorter than the thickness of the valve cover to account for the smaller diameter bolt. You can now torque down the bolt and get enough preload to seal the valve cover without removing the old gasket. Make sure you use a torque wrench ( in-lbs) or be very careful not to snap these small valve cover bolts.

SOURCE: Headlights turn on by themselves when vehicle is parked.

Do you have auto lights when it gets dark out? When they come on is it in a parking garage or home garage where its dark If so chances are your switch/relay unit is bad. (or do they come on in daylight too)?

SOURCE: headlight assembly switch does not work properly

I would say try replacing headlight switch...I have the same problem and will be doing that tomorrow

SOURCE: i have a 19991 toyota previa. the oil level light

If the light is flashing there could be problems with the electrical wiring. The easy places to check are at the bottom of the oil reservoir (pass. side under the hood) and at the driver side of the oil pan under the vehicle where the wires plug into the sensor. If this doesn't resolve the problem then it isn't easy, and testing the circuit will have to be done by someone who knows their electrical "stuff." Even the pump motor for the reservoir could be out.

If the Oil Level Sensor light stays on and you have already checked to make sure the oil level read on the dipstick under the driver side seat engine compartment is reading adequate, then you have a sticking oil level sensor float. Replacing the oil level sensor is easy, but extremely expensive ($485 in 2012). You can try to clean the plastic spool that the float slides on, but the problem is usually that it has swollen or expanded (likely from heat in the oil). One could try to sand it down but this would be difficult. I have made a new part out of nylon 6/6 on my lathe and replaced the plastic spool so far with excellent results. I'm considering selling it as an aftermarket part when I see if mine works. It would be a lot less than $485 dollars from Toyota. Or possibly have people send it to me and I'll repair the sensor myself.