Mazdaspeed 3/6 Custom Oil supply line “Built engines only”

We have seen a few Mazdaspeed turbocharger returns lately and all of them were oil contamination related.  All of the customers had built engines, and all the turbochargers had under 3-5K miles before they had oil smoke or a “not making boost target” issues.


We first would troubleshoot the problem by checking the crank case ventilation (catch can) and also restrict the oil volume entering the turbocharger (restricted banjo bolt).  When the customer took those steps, and the problems still existed, we requested that they return the turbocharger for inspection.  Here  are examples of what we find when we open the turbocharger!



Engine break-in material contaminates the oil being supplied to the turbocharger.  The bearings inside the turbocharger are made of bearing bronze which is a soft material made to absorb some contaminates but still function properly.  Too much contamination will cause pre-mature turbocharger failure.   Smoking and boost issues are the usual symptoms of oil contamination.   *Oil contamination issues are not covered under BNR’s warranty!*


Repairs typically range from $150-$400 to repair or replace the center housing rotating assembly.  If the turbo grenades, sometimes the end housings will need replaced which would add to the cost of the repair.


BNR Supercars highly recommends that built engine speeds have a custom, filtered oil supply line to protect the turbocharger from engine break-in debris.


Order these oil line parts from various locations.  Make sure oil lines are clean internally before installation!  This is not a kit and will have to be done custom!


(1)  Forced Performance Red inline oil filter-$65

(2)  Ebay M12 Banjo adapters-$14.99×2

(2) Summit Racing -4 an hose ends (SUM220490)-$5.97×2

(1) Summit Racing -4 an braded hose (SUM230406)-$23.97