I have a 2003 Jeep Overland with a 4.7 HO engine. When I am driving around 60 MPH the RPMs fluxuate between 1500 to 2000. the RPMs GO UP THEN DOWN THEN UP THEN DOWN. IT FEELS LIKE A VACUM LEAK OR THE TRANSMISSION DISENGAGING BRIEFLY THEN CATCHING AGAIN.This does not happen at idle. I have an emission diagnostic code of PO 325 suggesting possibly a bad knock sensor or weak air fuel mixture. What do you think might be going on ? Thanks Dan
P0325 is a knock sensor code, could be a sensor malfunction or a bad sensor, the RPM fluctuations sounds like you are shifting in and out of lockup in the transmission, could be a speed sensor misread, but fix the hard code first then go from there, don't forget to clear the ECM after the repair is completed.
Search Jeep Grand Cherokee Questions
Jeep Grand Cherokee Experts