I sent an engine oil sample for testing, before my extended warranty expired. Test showed a high fuel dilution of 9.5%!! My dealer wasn't aware of any concerns with this GDI 3.3 liter engine. I wasn't experiencing any problems before, or during my series of tests. They did an external pressure test and results were within specs. I drove it for another 3800km and sent away another oil sample for testing. It came back 8.55%. Dealer rechecked and said it was the secondary pump that boosts the fuel pressure for direct injection. Thankfully they replaced it under warranty.

But my concern from the start,is how much damage has already taken place because of potential lack of lubrication? No noises are noticeable, yet. Dealer says I'm good to go; they are confident there won't be any issues. I don't share that conviction, because once I drive off the dealer's lot, my warranty expires. I'm right at 120,000 km. The test results don't show a high level of metal wear happening yet, but I'll test again in awhile.

I write this to make other Hyundai 3.3 liter engine owners aware that you should consider sending away an oil sample for testing in case your pump is leaking.