I have a 2000 Ford Taurus V6 DOHC w/170K miles. When engine heats up, oil pressure light comes on, but only when RPM fall below 1500 or at idle. There is a burnt smell sometimes after driving the car. I do not see froth or coolant in the oil. Car burns a little oil, but no more than it has been for the last 50K miles. Just had oil and filter changed 300 miles ago; I was using 10W-30 but I believe the mechanic used 5W-30. (Also, if I drive more than 45 minutes, the “low coolant” light comes on-- however, the engine is not overheating, and the radiator/reservoir are full.) Any ideas as to what part(s) I should order first? Oil pressure sensor? Oil pump? (If at all possible, I need to repair myself, as I simply cannot afford my mechanic’s hourly rates right now.) Thanks for any suggestions.
The first thing I would do is get the oil pressure checked with a mechanical gauge when the engine is hot. The oil light coming on at low RPMs may be just a bad sensor, but it’s also a classic sign of worn engine bearings. If your engine has worn bearings, switching back to 10W30 (or a ‘thicker’ oil like 10W40) may enable you to get years more life out of it.
If your car has a temperature gauge, what is the gauge doing when the low coolant light comes on? Is it staying in the ‘normal’ range, or does it shoot up towards hot or down to cold when this happens? If the coolant is full and the temp gauge is behaving oddly, the first thing I’d do is to change the thermostat. If that doesn’t help, having a simple test done can rule out a head gasket problem.
Thanks; I’ll try putting in some heavier oil and see if that changes anything. The temp gauge stays stable when the coolant light comes on. I think it might be a thermostat problem.
That coolant light may just be a bad level switch. Not sure where it is but suspect it is near your overflow tank. When the light comes on, check what level it seeing. Maybe your level is legitimately low.
A bad thermostat usually doesn’t cause issues like that, I don’t think: If it is stuck closed, it causes overheating. It if is stuck open, it usually causes the car to take a long time to heat up.
The low coolant sensor is probably in the overflow tank. I know it is on the Ford Escort and sometimes the sensors get corrosion on them not allowing the sensor to detect the coolant and gives a false reading.
For the oil pressure problem I’d check around the oil pressure sending unit to see if it’s oily. Sometimes the sensor will crack allowing it to leak oil and pressure. This could explain the burnt smell and the low pressure both. If the sensor is cracked and leaking get this repaired ASAP I’ve seen them crack to the point oil was streaming out.
Check the Fluid level in the Radiator, not the resivoir when the car is cold. I have had cars go 30-40 thousand miles with the oil light on when warmed up at idle.
Does your engine have a sludge problem? Last spring after over 500K miles I had to remove the oil pan on my daily driver and clean the pick up tube screen for the oil pump, because of low pressure.
You said in the opening post that the oil pressure light was coming on. Then you said that the coolant temp light comes on. Which is it, or is it both??
If the oil light is coming on, it is either the pressure switch is faulty (or sludged up) or the engine is worn enough to lower the oil pressure.