Once in a while when I slow down, the oil pressure drops down to zero and the buzzer goes off. Raises back up when I accelorate. any ideas?
Cross your fingers and hope the oil pressure sender is bad. If the pressure really is dropping to zero you have a mechanical problem. Zero oil pressure can destroy an engine very quickly, so have this checked out ASAP.
A mechanic can measure the oil pressure, or lack thereof, with an accurate gauge.
If you just had an oil change, or are way overdue for an oil change, it could be due to the filter. Had this happen to me once, changed the filter and everything was ok. Defective filter.
i would have some one check oil pressure with a guage,could just be a bad oil pressure switch , or pump.but have it checked A.S.A.P
You are not alone. I have a 2000 Jeep GC 4WD w/4.0L with the same or similar problem. However, my Jeep only does it when the engine is warm (after driving 20 or so miles), and I stop and shut off the GC, then restart within a short period of time. The oil pressure gauge will read 0psi on restart and check engine light comes on. If I stay at an idle, the op guage remains at 0psi and check engine light remains on. Once I start moving and put a load on the engine, the op jumps back up to normal operating pressure and check engine light goes off. Makes sense to have a manual op check to see if it is an oil pump or sensor problem?
How many miles are on the Jeep?
While it might be the pressure sensor, usually this is an indication of a worn out engine. Also try changing the filter as someone suggested, however filters have bypasses built into them so that if they get that plugged the oil goes around the element and you don’t generally lose pressure.
The system builds pressure by pumping oil against resistance, that resistance being that it’s pushing the oil through small passages such as the spaces between your crankshaft surfaces and the corresponding bearings. When the engine wears to where the spaces become too big, the oil flows past too easily and the pump has nothing to build pressure against. It’s like trying to build up air pressure in (inflate) a balloon with a pinhole in it. That usually shows up at isle when the oil pump is being driven at its minimum speed, exactly as you’re seeing.
The only real solution is to provide a slightly thicker oil that won’t go through the spaces quite as easily. Or to rebuild the engine. Try a higher weight oil and see if that helps.
Post back.
- mountainbike
Use a 1/8 inch npt fitting with your test oil pressure gage to screw into the hole where you unscrew the oil pressure sensor. IF the oil pressure is not too low, it’s a problem with Chrysler’s wonderful electronics system. The engine is supposed to cut off when the oil pressure drops too low; but, what is “too low”? ---- To read an explanation of the dash gauges, go to: alldata.com through your local public library or a $25 year subscription to alldata. Go to: Vehicle Level > Instrument Panel, Gauges and Warning Indicators > Oil Pressure Gauge > Description and Operation <. These directions should help you find the data … it’s not easy to “get there from here”.
From alldata’s description (on another Chrysler, a 1998 Dodge Durango) the oil pressure sensor sends it signal to the engine computer (powertrain control module - pcm), which uses the Chrysler Collision Detection (CCD) data bus to send the signal to the instrument cluster circuitry (a logic module?) which moves the oil pressure gauge hand to indicate the psi. And, if the oil pressure is low (what value?), the instrument panel circuitry will set the gauge to zero. If too high (how high?) the instrument circuity will set the gauge to 110 psi. — This is engineering!?
The Jeep GC only has 75,000. I fly a lot so it’s typical week includes several days in the airport parking lot.
The manual pressure check did confirm that the pressure is a bit low when the engine is hot. Thus thicker oil and STP.
Less than impressed with the engine.