I have a 2000 Jeep 4.0 I-6 that has an engine rebuild at 107K but they used the original head not knowing that the 2000-2001heads are prone to cracking. I bought the Jeep at 117K so 10,000 miles after the rebuild, sent in a UOA which came back with high levels of coolant contamination. Found a crack in the head letting coolant into the oil. Replaced the head with a Clearwater and changed the oil. After 175 miles I sent in a sample, potassium was down from the initial 1879PPM to 139PPM. Changed the oil again and drove 700 miles, sent in a sample, potassium was down to 42PPM, changed oil, drove another 700 miles, sample came back at 26PPM. Changed the oil again, drove 1,000 miles, sample came back at 26PPM again, so no improvement this last time. I was careful to get the oil very hot before each drain, and let it drain completely even jacking up the front once it stopped draining to get everything out of the pan which resulted in another ounce or two. The filter was also replaced each time.
So I'm asking anyone who has been through this scenario is this normal to see the contamination level off like this?
Note: I did change brands of oil this last time to Quaker State All Mileage 10W-30 conventional, I had been using Valvoline Synthetic 5W-30 before that.
So I'm asking anyone who has been through this scenario is this normal to see the contamination level off like this?
Note: I did change brands of oil this last time to Quaker State All Mileage 10W-30 conventional, I had been using Valvoline Synthetic 5W-30 before that.