S54 BOOM!, S54 Autopsy, S54 Tear down, Failure.... bad day, subtle reason ☹️

Back when the e46 M3 came out I was frequent on the forum Roadfly and the saying was S54 BOOM!
From the build up it had 27000 miles, with only a coil dieing, I did alot of future proofing maintenance to it as well, it was set for a long road ahead! There were about 330 views of a previous unresolved iteration of the saga, now all is known, assembly error.
I drove it to VIR and had good gas mileage and no indicators for me that's over 500 miles. Then some weird limp mode like running and BOOM! No missing dramatically or anything else. So I am thinking electrics or fuel pump up until failure. No codes of worry were thrown. I did get a "system too rich" but that had been happening for some time, infrequently. The fault was found and it is a surprise at how subtle it was, torques on this motor are very small and especially at the failure point as well.
I had never been to VIR. Big thanks to the folks there for allowing my car to sit on campus until I could get it back.
Shout out to Photographer Scottie Elkins for getting me close to home!
In the end I was lucky it failed on track and not somewhere on the side of the road!

[@lolman-yn3jr]

Love the video, appreciate you giving us some insight into what can happen!!

[@samthing4thetrack806]

yeah it was a surprise for sure, and in the end I take the blame and loss. the second motor I am working now is getting some "mania"

[@adamchudomel6230]

Interesting video! Thank you for taking the time to make it

[@samthing4thetrack806]

Thanks, yeah, I feel stupid and not at the same time. A simple Pressure gauge would have showed the problem, but I didn't make it a priority. Oil Temperature I could see pan and post oil cooler. I had been thinking I really should put one on but didn't start buying the stuff. I have it now tho.

[@kirilakmadjov8307]

@@samthing4thetrack806 sorry about your engine bro i know its not cheap to replace one.May i ask did you had the low oil pressure light on the dash, i couldnt see it in the video at the beginning?

[@samthing4thetrack806]

@@kirilakmadjov8307 thanks man! dash pressure light is lost in the swap to e36, they are CAN to e46 m3 cluster. I only needed to spend maybe $200 for a gauge setup and do the work, and planned on soon but did not get to it in time.

[@uscp2]

Thanks for the informative video! with "chain tension not seated", Do you mean the chain has to be tensioned when torqueing down the oil pump nut? I just torqued down my oil pump nut, and reinstalled the pan. This video makes me kinda anxious. Engine is still out so I can still check/redo things if needed.

[@samthing4thetrack806]

u dont want the chain attached at all and make sure the gear is well seated which may be difficult to see on the back side given the shapes. before u torque it.

[@uscp2]

@@samthing4thetrack806 Ok! will open the crankcase again and retry. but how do you prevent the pump from rotating while you torque the nut?

[@samthing4thetrack806]

@@uscp2 25NM reverse threaded. That is low you can likely hold it with your hand. I would make sure it is clean and put at least blue loctite on it. Or other ways of staking the nut.