The car is a 2001 Jeep Grand Cherokee Laredo, with a 4.0L straight six. The past week we drove down from Pittsburgh to Myrtle Beach. Ever since we bought the car, the engine Pressure gage has given readings from 40 to 60 on everyday driving, and during the trip it gave readings of 40 to 70. The driver’s manual says that these readings are normal. Now the Check Gages light is on and after checking the other gages, the pressure gage is the only one that is not at an average reading. Any help or information would be greatly appreciated. Thanks
Check for codes using the (NOT START) ON:OFF:ON:OFF:ON(LEAVE ON) method and look at the odometer display.
There is no code for variance in oil pressure on the Jeep.
You haven’t said whether the oil was just changed …is due for changing …or is neither. But I don’t see a true issue either way in regard to the CEL.
If you’re seeing higher peak pressures, then you either have a higher visc fluid, the sensor is going slightly whacky on the higher side, or your oil pressure relief port is getting varnished/constricted. This is not likely since you report higher HOT temp pressures too (the relief would be out of the picture).
Change the oil and filter to start factoring the pressure issues. Don’t bother with paying for a verification with a mechanical gauge unless you’ve got money to waste. Replacing the sensor will be cheaper.
I used the method you described and the only thing the odometer said was “done”, then switching to the normal odometer display. Does this mean that there is nothing wrong with the car?
also, we were planning on changing the oil as well because we don’t know when the dealer or previous owner changed it
It means you shouldn’t have a CEL.