I'm removing a 2008 2.3L out of a 2008 Mazda 5 (91,000 miles with thrown rod and block damage) and installing a used 2009 Mazda 3 2.3L engine in its place. I noticed the replacement engine (80,000 miles) has oil residue in the manifold. I removed the manifold (engine is out) and cleaned it. Does anyone know if it is normal to have oil residue in the manifold...slight puddle in the sump of the manifold. Intake ports on the head do not look clean except where the injector spray pattern is. Doubtful the manifold has ever been removed. No history available on replacement engine.

Also, the original 08 2.3L (thrown rod) had an oil cooler on the filter housing, the replacement 09 2.3L does not. I was thinking of swapping the cooler/housing to the replacement engine to keep it simple with the existing hoses and tees since none were on the replacement engine. Any thoughts? I have read threads about issues with the cooler leaking.

Since the engine is out I'm considering replacing the timing chain, guides, etc., I read 90,000 is the recommended interval. Any other parts that are good to change at 80,000 while the engine is out? There are no leaks on the engine.

Thanks

 

Strip everything off the old & new engines and use everything off the old engine on your new engine. ( eg brackets, sensors manifolds etc. )

 

Oil gets in there via the PCV valve. Yours needs to be changed, because Mazda NEVER does..
You could also have gunk via the EGR valve, a good cleaning of that should help. Clean your throttle body and MAF. change all related gaskets, o-rings.

 

Thanks much! What about the injectors/fuel rail? I've heard the PCM could have issues with the different injectors but not sure why.

 

Are you re-using your old ECU? If so re-use your old injectors.