Hey guys, my car has leaked oil since I have rebuilt the engine in 2021 and in 2023. I have always attributed this to the oil pan, because the leak is heaviest near the left hand side (port side) motor mount; however, upon further investigation, it appears that the leak may be attributed to the oil pedestal. I have found small puddles of oil around the rear housing by the Mazda logo. Both times I have used new oil pans and installed the Banzai brace, when rebuilding. This last time, me and the builder were very careful in installing the new oil pan. We even waited a week before flipping the engine upside down and applying any pressure to the pan or mounts. When rebuilding and installing the engine this last time I installed a Banzai oil filter pedestal, so the o rings underneath the filter pedestal have been replaced. I am starting to think that maybe mounting surface underneath the filter pedestal is warped itself. Could this be the case? I have ordered OEM Mazda o-rings and will be pulling the UIM and filter pedestal to investigate further, when I have the weekend time to do so.

Does anyone have any thoughts or theories on how to combat this oil leak?

 

First off, if you're using the Banzai pedestal, are you 100% sure its leaking from O-rings and not from the oil cooler banjo fitting/pipe that attaches to the pedestal? When I first put on my Banzai pedestal, after a few heat cycles mine started to leak a little bit from the banjo fitting - I re-assembled the banjo connection with a new crush washer, and being very **** about FSM torque specs solved that problem.

I think it's less likely that any of the metal sealing surfaces are warped, but it's possible that the O-rings used may be the wrong size (SAE vs. metric rings?) or perhaps they were misaligned or pinched a bit on installation. Usually a poor O-ring seal here will be a gushing leak that's hard to miss, but sometimes it's less severe. IIRC, there are no O-ring grooves cut into the rear iron where the pedestal sits; it's just a flat surface, so you'll need a pair of O-rings that correctly fit the groves in the Banzai pedestal - check with Banzai for the correct size, not sure if they are the same exact size Mazda used on the OEM pedestal. To keep the O-rings from moving around or getting pinched on install, I like to use some Vaseline to keep them in place in the O-ring grooves during installation. Then torque the nuts to OEM specs.

 

a leak there will eventually get to that corner of the oil pan, so that part is right on.
there are a couple other spots besides the o rings that can leak too, oil filter, oil cooler hose, oil pressure sensor (careful not to go too tight on this, it can crack the engine)

i'm lazy, i'd clean that whole corner off really well and see if you can get out of actually having to do any other work....

 

I thought my aftermarket oil pedestal was leaking too. Turned out it was the plastic oil filler right next to it. The o-ring was either tired, not situated correctly or not the correct size or thickness.

I discovered this only after adding a dye to the oil and shining a UV light to find the leaks.

Also, it seems like the dye helped to show that what I thought was an oil pan leak is really oil leak from the motor mounts holes through the oil pan. Jury is still out on that one.
YMMV

 

Thanks for the suggestions! My job has been working me to death. Hopefully I will have a few hours tomorrow to clean up the block and search for leaks.

I didn't think about using UV dye. I will be trying this.