Rep Power: 211

My son and I plan on pulling a Mazda 2.3L engine soon to swap out the oil eating, rod knocking, dud that's in his car presently. This will be his and my first engine pull and replacement. My auto repair knowledge is intermediate and I'm pretty confident that we can get it done without too many issues.
The yard provides a hoist and the cars on on rims. I'll list tests that I assume are good prior to pulling an engine however, please provide more suggestion and/or tips .

1) Manually cranked compression test; My concern with this one is that by EPA laws all fluids are removed from engine/vehicle before parts can be removed and sold. If that is the case could manually cranking an engine (for compression test) cause scoring on internal parts such as crank, pistons, bearings?

2) Leakdown Test: Obviously one of the most comprehensive test but, does it find loose tolerances that leads to oil consumption?

3) Visually inspect intake manifold, throttle body, exhaust manifold ports and spark plugs for signs of high oil consumption . Excessive buildup in intake ports and cylinder head intake ports could mean excessive oil consumption

4) Inspect spark plugs for coolant, lean or rich fuel condition, oil on threads: valve cover + spark plug tube gaskets breach.

5) Move each piston just past TDC on downstroke and use a long flathead screwdriver to test for rod knock . Same concern for manually cranking engine listed on #1.

 
Rep Power: 519

Deal with a reputable recycler who stands behind their sales with a decent warranty period and not a lot of hassle to get warranty coverage.. At work we use LKQ the most, they seem to ship nationwide and have scads of specialty yards.
http://www.lkqcorp.com/en-us/

Don't slack off, get that sucker changed and running ASAP so you can figure out if it's gonna be a winner before the warranty runs out.

If pulling it DIY, see if you can hear it run BEFORE you commit to purchase.
1-I don't think I'd do it without oil in it.....and a compression test cannot tell you anything about the oil rings. You want to do compression test hot too.
2-yea and nay, it may be a decent idea but it can't tell about oil rings....and you'd have to plumb air pressure to the location?
3-you don't know that for sure.......I've received used engines that were almost preserved by drowning in oil, they fog oil in while it runs-- until it dies-- so all the internals are coated and somewhat protected. Most manifolds get crud and goo in them anyway, from EGR and PCV systems.
4-plug check yea, crusty white ash buildup is long term oil burning
5-interesting idea....maybe, but there would be little oil in the bearings.



Do any boats use the same engine?

 
Rep Power: 230

Are you swapping to a new engine type or just replacing the same engine?

If you are replacing with the same engine type I would suggest rebuilding the original engine.

That way you will know everything is up to par.

-inspect the head replace any damaged components/seals
-pull head replace head gasket and inspect head for damage/warping.
-replace piston rings/re-hone the block (check piston wrist pins and crankshaft bearings).

Here is a link walking you through this process for a honda it should be similar for the mazda.