I have a 2000 Jeep Cherokee 4.0 (I-6). Never had any probs other than the evaporator for the A/C. 75K miles. Very regular oil changes and very well cared for. Cranked it up this wkd for a country trip and the oil pressure guage pegged and stayed pegged the whole weekend. Never went back down. Less than 500 mi. on last oil change. No temp problem and oil is not overfilled, leaking, ect....

Any ideas?

TIA