Engine differences question

I have a 1998 Olds Aurora that I absolutely love to drive. My problem is a major engine issue and have been advised by my family’s mech. I’d be better off getting rid of the car.

In looking to get a replacement engine, I checked a supplier’s website and noticed they have the 1995-99 4.0L V8 for over $7k and the 2001-2002 version for under $2k.

Any guesses as to what the difference would be with these engines? BOTH are listed as 4.0L V8 (L47-C) and the specs when looking up each vehicle are identical.


You might call a junkyard, they should have and ‘interchange’ manual that says whether these two are equivalent. There were pretty big developments in engine control and computers over that time, it would not surprise me if they do not interchange, but I don’t know.

My impression of the few Auroras’ I worked on was that a 1998 that needs an engine at the end of 2010 is used up, not worth putting an engine in.


Not anywhere near the case. Aside from the engine the car is nearly SPOTLESS!!! NO body rust, good shocks/struts, brakes are still over 60% and I’ve put close to 50,000 on it since I bought it. No squeaks or rattles either.

The only problem is the cost of the engine listed for the 95 - 99 models, as in I don’t have that kind of money…

I have thought of just pulling it and doing it myself except I haven’t done engine work in over a decade and really have avoided doing car work myself for longer than that.

You’d have a lot of trouble workng on that v8 - I think it’s derived from the Northstar v8 from Cadillac, not made for rebuilding.

I know - I was trained on the Northstar when they first came out - Now years later, here I am thinking of playing with it anyway…

I really need suggestions on where to find the answer to the differences in the 95-99 and 01-02 and the 03 engines. Is it motor mount locations (different castings)? Cam set-up? Transaxle mounting pins & bolts? Sensor locations? There are way too many variables to try and figure out alone. Maybe I should just go check out the junkyards… I know of a couple that claim to have the different engines and might be able to look at them and see if any differences are noticable.

There does not appear to have been any changes made throughout the L47’s lifespan. That said, there’s nothing saying they didn’t do something silly like change one little part without telling anyone. You’d probably be best off asking this on a dedicated GM/Aurora forum.