Maybe bad oil was allowing for some metal to metal contact?
How many miles are on your engine? Ever have low oil pressure or moments of very low oil?

 

140k miles on the clock, as far as I know I've never been low on oil. Although it I stop abruptly the oil light comes on for a a quick second

 

Just picked up a 100k mile engine from a 2004 Manual.
Need to swap over my auto flywheel, my harness (as this one is cut all over the place) and put it in.

Looking in the oil fill hole it looks clean and golden.
I will take the sump off and check for metal filings/shavings/oil quality and check the pickup.

Anything else I should check before dropping in ?

 

Finished swapping the engine and bolted up test pipes and hks rep exhaust whilst I was at it.
Trying to drive home, the car idled fine but a little bit of throttle and the engine would backdown, lose power and there was some backfiring. It was bad enough that the engine wouldn't maintain it's revs and just stalls. Also, the vdc/slip lights were all lit up.

Any suggestions?

 

Well, I scanned and found a code for crankshaft sensor. Changed it and all is good again.
I was surprised because normally when they go the engine needs 6/7 seconds before firing but this one would start straight away but just run terrible with backfiring and struggling to rev.