QuestionI just came home from a long trip in my PT Cruiser. (2004 model, autoshift, 2.4Litre, non turbo) I bought the car in late July and until now, it has been trouble free. I drove the car about 180 miles from my home and it was no problem. I stayed a few days, and drove the car around the town where I went without problem. When I was on my way home, and just outside of town, (about 30 minutes of driving) there was an accident and all traffic was stopped including myself. While standing still, the "oil lamp" came on, and it was my notion to stop immediatly. I stepped on the gas to get into the safety lane, and the light went off. I checked the oil level, and it was on the "MAX" mark on the indicator stick. I got back in, started the car, and the light did not come on. I drove about another 30 minutes, and it came on again when I stopped to get some coffee. I checked again the oil...same thing. I drove the car about 90 miles to the next town. When stopped at a traffic contol, the light came on again, and went off when I pushed the gas to go.
Of course I called my husband who asked me some questions. They were, Do you hear "clacking noises"? (no), Do you smell burning? (no) Is any smoke coming from the tail pipe? (no) Is the car running rough? (no) Does the light come on when you are moving? (no) Is the temperature guage registering higher than usual? (no)
He told me to continue home, and unless the light comes on while the car is moving, it is probably OK. Well, I drove the car, at highway speeds about 90 more miles. The light only came on after I got into the city and stopped at various traffic control features, including a long one at a "sobrety checkpoint".
Now, sometimes the light comes on, and sometimes it does not, but only when the car is not moving, such as at a traffic stop, but the car runs fine and the oil level is fine also. What is the problem? Is it serious or an indication of a serious problem that may befall my car? My husband told me to ask "Is it very unusual for an oil pump to give out gradually?" How can this be fixed. The chiming kinda gets on my nerves, as it was designed to do I am sure.
AnswerHi Zanubiyah,
This is quite common and usually is not a problem. There is a minimum oil pressure requirement for an engine at idle speed (4 pounds per square inch). There is an oil pressure sensor near the oil filter which is supposed to alarm at about that level or less but it can be inaccurate. So one possible service would be to verify exactly what is the oil pressure when the sensor is alarming, using a calibrated pressure gauge substituted for the sensor. If it is alarming at too high a pressure setting, then replacing the sensor is the solution to put your mind and ears at ease.
The other possibility is that the pressure is indeed at or below 4 psi at idle when the engine is warmed up. If that were the case, the easiest fix for that is to change the engine oil and substitute the next higher "weight" of oil. If you have had 5W-30, use 10W-30 instead, if 10W-30 then 20W-40 etc. The higher the number the higher will be the pressure at idle, so chances are this will solve the problem equally well.
I don't think the pump is likely the problem, but if you would like to know that also get the pressure measurement at 3000 rpm which should be 25-80 psi. If it is in that range then you will have no concern about the pump or the oil system.
I would begin with the oil change with substituting the next higher weight of oil. In wintertime you may want to drop down to the present weight for ease of engine cranking, and because the oil will not be so hot (thin) as now the problem will likely not resurface.
Only one caveat here, you did check the oil level on the dipstick, but also observe whether it is cloudy or foamy which would indicate that there is also engine coolant in the oil (which would cause reduced pressure readings) and that would require immediate attention because of potential damage. But if the oil is normal-looking that can be put away as an issue.
Roland
