Rebuilt or Low Mileage engine

Rebiult is better,you keep the original engine,may cost a little more than just buying a used engine,but in the long run you will have like anew motor when rebiult,instead of a engine you dont know anything about.

You might want to consider which of the two options provides you with the best warranty. Rebuilt engines can have slightly lower performance than an original engine because of the machining that's done in the process. A low mileage engine is more like a new engine since there's no machining of internal parts. In my opinion it comes down to warranty coverage. The longer the better and the best one would include no labor charge to change it out if it fails during the warranty period.

Ok thanks for the advice. I'm having issues with this car & a few mechanics couldn't find the problem. Long story short.... I had the engine rebuilt but needed a valve adjustment. Got that done but now has low compression (like 50 psi) in cylinder 1. Also I saw black smoke so I'm thinking it's dumping too much fuel to. I'm not a seasoned mechanic. I'm lost after a oil change. Lol! I'm just searching for the best way to repair my car & not break the bank! Any ideas...?

A properly rebuilt engine with warranty would always be better than a used engine. You will likely never know if a used engine was abused or how it was serviced. A properly rebuilt engine will likely have slightly more power than a used engine due to it being put back into spec. and the carbon that accumulates on the back of the intake valves being removed. Perhaps the low compression is caused by a valve that is set too tight making it slightly open when it is supposed to be closed or maybe the valve is bent.