I've just purchased a used Chevy Lumina Van 3.8 engine to put into my Bonneville. Both are 1994 models. I have the factory books, and some previously-received warnings on how difficult the one trans bolt is to remove.

Today I would like to ask if it is required or advisable to swap over all the sensors from my motor? My motor has bad bearings, but never turned on the check engine light.

This motor was tested in the vehicle with no issues, but I was told by another mechanic I know that it is sometimes necessary to swap all the sensors in case the two motors didn't get the same sensors or come from the same plant.

Thanks for any insights!

sensors should be fine

you will most likely have to change mounts like the a/c compressor mount and motor mount
if the other one is different

The trans bolt isn't hard...You support the car, pull the passenger tire...remove the one bracket in the way and then use every long extension that you have.

shh between me and you i never bolt that bolt back in its hard enough gettin it out cuz you can barely see it

I've got a 1/2" drive extension that must be at least 36" long. Will that be long enough, or will I have to add more? BTW what size is the socket I'll need? And, is a straight-in approach with the extension(*) workable?

Looking at the passenger wheel well, approximately what position is that bolt? I haven't found any exploded diagrams in my factory shop manuals to indicate where the bolts are or how many...! Don't you just hate that?

That bolt is at the 11:00 position, from the passenger side wheel well. If I remember correctly, it'* a 15 or 17mm. You'll need more than 36". When I did it on my 87, it took about 42" of extension. That gives you clearance for the ratchet/breaker bar in the wheel well.

Yeah.. 3/8 will probably do it..but you need an extension almost as long as your bonne

Thanks again for all the tips. I'm now in the thick of this, and about to disconnect the engine from the transaxle...

The lifting rig I'm using is a chain and winch over some (4X4) rafters in the garage. The service guide says I have to support the transaxle before I disconnect the engine.

I have a logistical problem... If I block the transaxle from below, then winch out the motor, I won't be able to roll the car back in order to set the motor down on its dolly, and roll up the replacement for insertion.

I guess my real question is simply this: can the transaxle be supported from above (or not at all) allowing the chassis to roll out from under the picked motor, then back under the replacement?

OK, I think I answered that last post myself. The trans does NOT need any support.

The replacement motor is in... and it'* bad too!

The yard promised another motor to replace it, and I'm insisting on hearing it run before it'* pulled. Any tips on what to look for besides the obvious? (dipstick, good idle, smooth cranking, no smoke...)

Already this has become more of a project than I planned on. The prep on the motor took much longer than I anticipated, and longer even than the time to R&R the engines.

Thanks!