If an engine makes no noises, does not appear to consume much oil, and appears to run just fine, is there any point to rebuilding it if it has over 100k miles on it??

I know later roller cammed cars supposedly do not experience as much wear to the cam as earlier models. To use my Formula as an example...103k miles, no noises, starts up, only blows smoke on start up (valve seals I assume??), and was down 2.5 quarts of oil when I got it...but had gone 9,000 miles on that oil change! So less than 1 quart burned in 3k miles isn't a bad thing!! I assume she never added oil to it...its doubtful a 55 yr old CPA had ever popped the hood

So if an engine is running strong, doesn't make noise and doesn't burn excess oil, is there any major benefit to a tear down?? I won't do it for awhile solely because it is running so good, and it needs other things. Just wondering if I am losing much performance by having a higher mileage engine...

 

Acouple of years ago I had a freeze plug go out in my 89 GTA that had 92,000 miles on it...I was faced with the dilemma of whether to lift the motor and replace the freeze plugs,or just yank it and rebuild it.My car was the same way,ran great,valve seals were shot, but the car was fine..
I decided to yank it,and I'm glad I did because there was nothing wrong with it.The rod and main bearings looked like new,and the cylinder walls were in good shape.So I had the cylinders honed instead of having to bore them,and didn't have to put any oversized bearings in.So I'm glad I did it even though it really didn't need it.............

 

if it is running fine then unless you want to do it for your own pleasure, then wait, My IROC-Z has over 170K miles and it still runs like a champ!!

 

Here, mechanics recomend the following (aprox.):

- Volvo cars: overhaul over 300k miles.

- American cars: overhaul at 250k miles.

- Korean cars: 75k miles (impossible overhaul).

But , the miles depends of the driving conditions : normal (city), extremely or highway (I knew a Toyota truck with 500.000 miles without overhaul).

Chilton's manual recommend: "when the compression is at 80% from a new engine" . Mechanics recommend wait until 70%.

My experience: wait! you have a good engine. Be happy.