Hey guys,

I recently did an oil analysis with black stone. I was running 5W-20 15k mi Mobil 1 synthetic on my 08 V6 with 130k. The oil had about 11-12k miles on it. The oil analysis came back as having developed a coolant leak, which the lab said is evident by sodium and potassium in the oil. I did another analysis about 6mo ago with a sample from the same oil as this sample but with only 5k mi on it. That first sample had 0 potassium and 10 sodium (not sure what those values indicate). This sample, which was a full oil change had 159 potassium and 39 sodium.

I also did a water pump replacement a few weeks ago. I didn’t think I had an issue with the pump but when I picked it up the shop showed me some crusty pink spots where it had started leaking. I used an OEM pump and gasket, but the shop used zerex coolant. A few days after, I noticed my coolant tank was almost empty. Figured the shop didn’t do a good job with the fill and I put more valvoline brand pink asian zerex coolant. I’ve since been on a 2k+ mi road trip and haven’t noticed any more coolant issues, still at the ‘F’ line since refilling it.

Got it, it’s a V6 so head gasket may be an issue. But it’s an 08, so hopefully not. My 04 had a head gasket leak and I feel like I was always putting coolant in the tank. I guess I’m wondering if during the water pump maintenance, oil could somehow have made its way into the oil supply?