Oil Pressure Gauge Diagnosis

Oil Pressure Gauge Diagnosis

An oil pressure gauge malfunction can result in any one of the following conditions:
- pointer dies not move,
- pointer moves but indicates an oil pressure that does not correspond with the actual oil pressure,
- pointer moves to the top of the scale and remains there,
- pointer pulsates.

Refer to Diagnosis and Repair Simplification (DARS) Charts 4 or 5 for a systematic method of locating the causes of these abnormal conditions.

Calibration Test

If an oil pressure gauge is suspected of indicating pressure that does not correspond with that actual oil pressure, perform a calibration test before performing electrical diagnosis procedures in Diagnosis and Repair Simplification (DARS) Chart 4 (CJ) or 5 Cherokee, Wagoneer.

1. Remove oil pressure sending unit from cylinder block. Install T-fitting in cylinder block. Connect sending unit to T-fitting.
2. Connect oil pressure test gauge to T-fitting.
3. Start engine. Compare pressure indicated on vehicle gauge with that on test gauge. Conduct comparison at idle and at higher engine speeds. If both gauge indications are same (within 10 percent), vehicle gauge is acceptable. If gauge is not within specifications perform gauge test as outlined in Diagnosis and Repair simplification (DARS) Chart 4 or 5.
4. After performing test, remove T-fitting, install sending unit and inspect for oil leaks.