Hi, i have a 1990 honda crx ef project car. it has a d15b in it currently, Running on 3 and blowing smoke so maybe head gasket. But no oil in water and vise versa so not sure. i also have another healthy d15b thats been pulled from another car. i was just wondering if it would be easier to try and find the problem with the motor and fix it, or to swap in the healthy d15. keep in mind this is my first proper project car and i have never pulled or dropped a motor but i know more experienced people that would help. got a sufficent garage with all the basic tools needed to pull something like that off. what would be the best way to go?

 

I would swap the motor, can be done in a couple hours if you have the right tools and a cherry picker then fix up the bad one for a backup..

 

Agree - swap the engine, then if you want, see if you can fix the one that's down a hole. I would do a compression and leak-down test on the one that's currently in the car before you pull it out...unless you plan to just do a full tear-down and rebuild. That will help diagnose the issue. Being down a hole could be several things ranging from a hole in a piston or a bent valve to something as simple as misadjusted valves that wouldn't require pulling it apart. Smoking is likely indicative of either rings or valve seals, though.