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      08-16-2020, 08:09 PM   #1

Drives: E46 M3 x2, E46 Touring, E63 M6
Join Date: Aug 2020
Location: Boca Raton, Florida

iTrader: (0)

Engine tries to start but doesn't after rebuild

Good evening my fellow E46'ers

I love the generation I have 3 E46's 02 M3 Convertible 6speed, 04/06 M3 coupe which is now a six speed, 03 325I Touring (eventual M3)

I come here today seeking some input and knowledge from the gurus out there!
Last year November I purchased my 04/06 M3 coupe originally a SMG 1/2 converted to 6 speed with a non operational engine.

My plan was to transplant my fully functioning S54 from my convertible into the coupe due to its "blown engine"
Upon removal off the engine and tear down I found that the exhaust hub tabs (both) were sheered off completely and it had a snapped timing chain.
After removing the head I found the worst of it. Cylinders 4 and 6 had 2 bent valves each.
After coming to this discovery I said to myself ill just rebuild this engine from the bottom up and leave my convertible for the donor swap into my wagon. So I did a complete tear down of the block down to every nut and bolt.
New piston rings, cylinder wall deglazing, new rod and main bearings, all seals, etc... you get where im going complete overhaul.

Fast forward 8 months after initial removal off the engine it is now back in the car.
Bellhousing conversion done for OEM feel/look, all wiring and lines connected, all fluids filled.
Today was the first day that I had tried starting after finishing buttoning everything up.
I turned the engine over a few times to circulate oil and build oil pressure without the fuel pump. Then plugged in the pump clenched my cheeks and turned it over. It turns over, it sounds like its trying to start up but it won't.
A few times it got really close you can even smell the fumes from exhaust. But nonetheless won't start.
I have checked all of my connections, grounds still nothing.
I scanned and clear codes and I am left with the same ones each time now.

2C DME: Signal Thermal oil-level sensor
A DSC Pressure sensor code
and some headlights and other misc ones since front end isn't completely back together.

Not sure where to keep going so I thought id stop and ask for some insight.

In addition the only differences in the way the engine is between how it came apart and now is I have replaced the OEM headers with a set from Active Autowerkes (rear O2's not connected) and Status Gruppe section 1.
I tried connected the rear O2's for fun and see if it made a difference and it did not.
I triple checked wiring to Pre cat O2's

So anyone got any ideas where I can look to find out why the hell it isn't starting?

Thank you in advance!

Few pics across timeline
Appreciate 0
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