1st Gen 100K+ If you had an 89K engine on the stand... (long post)

Sounds like a good list.

ATI crank damper
Change the supercharger oil
Look at the water pump & replace if you find wear.

That's all I've got, I'm sure others will chime in with more.

Welcome to M/A

 

Thats a good list of "suspects" to make this thing bomber.

perhaps 1) oil pan gasket if you didn't already have that in mind with oil housing/cooler seals... its easy at this point and cheap R&R and 2) If the water pump is ok I'd at least change the o-ring seals (behind flange to motor and pump) -- again another cheap R&R

 

I think you are 100% on the right path...
Heck, all the stories I have heard says doing a rebuild on a mini motor is nearly cost prohibitive... Simple things cost 3x what you expect, so a factory rebuild is cheaper than a diy in many cases...
At 90,000+ miles, the motor is IMO pretty young...sure it is 10+ years old, but one thought...
Any idea how long the motor sat? I would hate to install it to find The head gasket is corroded or it pings from valve wear...you are talking about putting a LOT of time and $$ into a motor that is a bit of a crap shoot...sure it SHOULD be good...but if it wasn't, the provider would likely just give you a second one...and all would be lost...
My gut says...do the cheap and easy gaskets and o-rings....
Look it over install...then run it...
Why?
Well life has a funny way of happening...
And just to be the devils advocate, what if it was wrecked a week after you finish...
That's WHY most shops try to match the age/miles of the motor to the car it goes into...minimize the risks....
Sure...spend $200 in cheap gaskets...but I might hold off on more $$ stuff, and do them as needed..
Sure, MIGHT be more $$ overall....but might prevent lots of work for nothing...
Just something to think about!
Good luck!

 

I like Zippy's thoughts.
I would tend to leave the timing cover gasket and crank oil seals alone if not leaking.
The crank sensor o-ring is a good idea.
I am on the fence about supercharger oil and water pump replacement.

 

I'd change SC oil. 3 bottles at $12 is much cheaper than $900-$1500 for rebuilt-new SC. I don't think you need 3 bottle -- 2 tops. More in the front reservoir less in the rear behind the water pump. Pumps are ~$100 but if its not weeping probably ok.

Also not certain this would've helped previous oil escape but might want to add oil pressure gauge to the list.

 

Headgaskets are a SEMI no worry item...
Folks that have issues have USUALLY overheated it a few times, and often have missed the coolant changes....
Coolant seems to be the most ignored item on these cars...
When delivered, these cars still needed a 3-4 year flush...the fluid was at the time NOT (saw the change in BMW/mini marking the bottles) a "long life" fluid....
With bmw, they switched the specs on the bottles of coolant (lifetime wise) when they switched from the old white bottles to the silver....funny the folks at the dealer I bought it hadn't noticed...
New specs say, for an aluminum block, to just drain what is needed for work, then refill with fresh to full, unless a "new" aluminum" item is added or changed...
No info on s cast iron...so I have been sticking with the old spec of drain/flush...the BMW undiluted coolant is pretty cheap...

 

Do not forget timing chain guides and the tensioner bolt for the timing chain. The guides are plastic and I just did mine at 90k and one broke when we took it out and put it on the bench.

When you start up the used motor it may sound like crap if the timing chain tensioner is stuck.