What year is your Kia? In some 95 the plunger in the oil pump is to short and the presure can get low at idle. If your pump is getting weak it could do the same thing. Kia fixed mine under warranty but that was years ago. You can check with Kia and see if they have a service bulletin on it.

Dennis

95 Sportage, gone but not forgotten.
98 Jeep TJ, 4" Zone springs with RC Long arms, Ford 8.8", 4.56 gears & Detroit locker rear, D30, 4.56 & Detroit Trutrack front.