Hi,

It looks like our 2017 Audi Q7 3.0 V6 has burnt a valve. It currently has 105,000 or so miles. Rebuilding the head with the burnt valve would be around $8k, but I worry that a valve on the other head might fail. We also had pretty severe oil burning that I was going to try to fix with a Liqui Moly flush and pouring a potion of marvel mystery oil and sea foam in each spark plug hole, I saw several people say this had reduced their oil consumption significantly, but there's certainly no guarantee. For this reason I was thinking about getting a rebuilt engine is around $15000.

I'm assuming the remanufactured engine is maybe not quite as good as a brand new engine, so I'm conservatively assuming it's life would be 90,000 miles. How likely is it that the rest of the car will go another 90,000 miles? Consumer Reports says the transmission is very reliable, but not the drive system which they say consists of:

Driveshaft or axle, CV joint, differential, transfer case, four-wheel-drive/all-wheel-drive components, driveline vibration, electrical failure, traction control, electronic stability control.

Replacing a CV joint or an ABS/traction control sensor wouldn't be too bad, but a differential would be. What other problems would this car be likely to experience?

Thanks