Identifying 2.5 or 2.7 motor

[Derek Grozio]

Recently acquired a 1999 986 where the owner noted that the motor had previously been replaced by Porsche under warranty. The mileage they identified it was replaced at would put it at the work having been done around 2001 or 2002. I assume they would have put a crate 2.5 back in the car for sake of ease and less impact to replacement, however there were notes on a few of the IMS reference materials out there on the net that Porsche used whatever was being produced at the time.

 

Is there a way to identify if Porsche replaced it with a 2.7? I know the O2 sensors and the AOS changed for the 2.7 vs the 2.5 and was going to start there, but unsure if those parts can be successfully swapped from the 2.5 to 2.7. Essentially looking to identify if I have a dual row IMS bearing without opening it up and poking around.

 

Thanks!

[JFP in PA]

4 minutes ago, Derek Grozio said:

Recently acquired a 1999 986 where the owner noted that the motor had previously been replaced by Porsche under warranty. The mileage they identified it was replaced at would put it at the work having been done around 2001 or 2002. I assume they would have put a crate 2.5 back in the car for sake of ease and less impact to replacement, however there were notes on a few of the IMS reference materials out there on the net that Porsche used whatever was being produced at the time.

 

Is there a way to identify if Porsche replaced it with a 2.7? I know the O2 sensors and the AOS changed for the 2.7 vs the 2.5 and was going to start there, but unsure if those parts can be successfully swapped from the 2.5 to 2.7. Essentially looking to identify if I have a dual row IMS bearing without opening it up and poking around.

 

Thanks!

 

Welcome to RennTech

The answer to your questions is yes, Porsche would have put a reman 2.5L engine back in the car, that is their policy.  As for the IMS bearing, it would have been whatever was being used at the time of the engine reman, and 2000-2001 was a transitional period where they were moving from the dual row to the single row.  For the good news, you can read the engine number off the sump rail and decode what engine it is, the IMS bearing is another issue, and may require visual inspection (pulling everything apart to see which one it is).  There are no other proven ways to determine which bearing is in an engine from that period., you simply have to go look.

[Derek Grozio]

Thanks, since the mileage is pretty low on the engine I'll have it on my list sooner rather than later to pull it and make a project out of it!