I keep cars forever and it has been my experience that other parts fail on the car long before the engine gives out. I had a Honda Civic wagon with 262,000 miles, the engine ran fine, but the transmission was making a noise, the CV joints were clicking on both sides, plus quite a few other little problems. When I added it up, it didn't make economic sense to spend $1,500 on a $500 car so I sold it for $300. My old Acura, I decided to spend $1,500 on it when it had 160,000 miles old. It now has 183,000 miles and the engine is just fine.
Unless you see a problem with your engine I bet it will be fine for many years to come. BE SURE to change the oil often. I do know that buying a re-built engine instead of getting a brand new engine is usually the best way to go, if your engine ever should fail. I have no idea what the cost of a new engine would be though.
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2001 & 2004 Toyota 4Runner SR5 4X2
Both V6 and both Natural White
"Yeah, I like white and I like 4Runners"