When vehicle stops the oil pressure drops to zero and the check gauges light comes on. when vehicle takes off the oil pressure picks up to normal again.
So you either have an oil pressure problem or a sender problem, you need to hook up a manual gauge to find out the actual oil pressure is.
you probably have a cracked head, the 2000 to 2001 cherokees had that problem. if you caught it early enough, you can swap the head from a 02-04 grand cherokee. if not, your engine might be gone.
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