Oil pressure gauge always read very high, and did not fluctuate. Brought to dealership, they replaced the oil sending unit. Get five lights away from dealer and now my oil pressure reads low when car is stopped and engine is idling. I bring back to the dealership because now the check oil light comes on because the pressure gets so low. Now they tell me I have to replace the oil pump and because of its location it will cost me $1800.00. this is ridiculous. I bought the truck at 50K and should not have had this problem.