Engine "reconditioned" by Porsche
 

Hi all,

I just bought a 2001 Boxster S. I really like this thing. I got many service records with the car. The engine was replaced under warranty in 2005 because of oil in the coolant. I guess it was one of the porous blocks that got through.

My question is about the replacement engine, which is referred to on the dealer work order as "reconditioned". It has the AT in the engine number, meaning (the way I understand it) that Porsche did the rebuild.

Does anyone know how much was done to these motors by Porsche? Were they rebuilt from stem to stern, or did they just fix whatever problem(s) the engine had?

I can't find any info on these engines. Any insight will be much appreciated.

I'm also interested into having a bit more info on these engines.

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I know this isn't your question. Is that what the dealer records show in the work order as cause for rebuilt? You said you guess. You have a 2001 so your engine should not have been affected by engine porosity. To my knowledge, a solution for a redesign casting started in the late 99-00 period to fix this issue. AT on the engine does means rebuilt engine. What is the exact reason for the rebuilt?

My car build date is 12/00. The first page of the work order says coolant found in oil. A little further down it says oil found in coolant reservoir. Replacement OK'd by someone. The reason for the problem is not stated on the work order.
Replacement engine # is M96/21AT67165040.

The intermix may have been caused by a cracked cylinder head .

You may be right about the cylinder head. Not a popular problem, but it is out there.

Now, about that engine reconditioned by the mother ship...

My understanding is that Porsche does not rebuild and return your motor, but rather provides a factory rebuilt motor that was returned earlier by another customer. This is done to reduce downtime. The motor is rebuilt to new tolerances.

Thanks, Paul.

It appears that these engines are a mystery. I knew it had a rebuilt motor when I bought it, but was curious about the extent that Porsche reconditions them. Rings, bearings, chains? Do they put the latest updates on them? Do they have mileage limitation on the ones they recondition? No one seems to know. I assume they know what they are doing, I guess. Or maybe just the cheapest way to satisfy a customer. It runs great and is clean underneath. The oil filter was clean. I am happy. Ignorance is bliss.

These M96 engines were Porsche first water-cooled engines. There were revisions made to address common and/or future issues during the production cycle. I think the % of engines that were affected were so small so this information is hard to gather.

As Paul mentioned, Porsche will sent out a refurbished engine to the dealership and the techs just install it. The dealership might not have the information on the refurbished engine and what was done to it before. The engine was covered under warranty as you stated so the car wasn't abused or tracked enough if any for Porsche to deny the warranty under abuse.

The cracked cylinder heads affected some S and 996 engines which resulted in the coolant/engine oil intermix as rfuerst911sc stated. This is more likely than the engine porosity for your year.

Whatever Porsche did to the engine must have been the latest shop revision at that time to fix it and pass a thorough inspection.

To the best of my knowledge, no one really knows the standard or specification (for condition and tolerances) to determine the work performed or parts replaced on a M96 Porsche factory reconditioned engine.

Again, to the best of my knowledge Porsche started with a used engine (maybe running, maybe not running, maybe with some engine failure) and based on a teardown inspection replaced whatever parts were required to return the engine to this unknown definition of acceptable condition and tolerances. Then they shipped it out to a dealer for retrofit.

Not the cylinders.

I read somewhere once where I believe either Jake Raby or Charles Navarro took apart some "factory rebuilt" M96 engines and that person reported all of these engines had new cases. Whoever that was said it was because there was no way to make the cylinder bores in the used engine cases perfectly round again because of the cylinder bore coating (alusil?) and how it wears. Of course I can't find that article now.

Yes, if the cylinders were obviously worn too much they would replace the cases.

If these engines have new cases, then probably a lot of new internal wear items, as well. Good info. Thanks.