toastedhalfbagel

In the market for either a 996.1 or a 997.1, and came across a '07 C4S with a 'refurbished' engine, due to history of bore scoring.
According to the seller, "engine was replaced with a Porsche supplied Remanufactured short engine assembly... and carry a warranty until September 2024."
Anyone know what this might mean? The warranty does provide some peace of mind, but does a previous history indicate a higher chance or the problem recurring in the future?

Thanks in advance!

voiceprint1

ask if the warranty is transferable and what if anything it covers, usually there is a reason a seller is wanting to sell right before an expiration date, 14 months is not a lot of time for a new to you car.

Others have more experience, but if it's a factory piece they might have updates done to the engine, but I would not bet on it.

rileyracing1

No updates on an oem short block that would prevent future bore scoring ... A fresh short block is nice but it is certainly not a Raby or fresh rebuilt engine with Nickies.

r_towle

I looked at those before choosing to rebuild.
it’s the same problem…same ims, same cylinder technology.

I think the issue is enough that a bore scope to see what’s up would be wise. Then buy it. A rebuilt motor is new….so you have 100k to play with the car.

see if you can find ALL the records since it was rebuilt.
oil changes…how many and when, and what oil.

63mercedes

Dont they typically put all the old accessory drive stuff back on the new block. Even if the block is new the water pump, coolant tank, ac system etc could be old. Make sure you treat it like a regular PPI. Unless you have a document stating why it was replaced it could be for any uncertain reason but an IMS or scoring is most likely the answer. I wouldn't even look at a 996.1. The car doesn't have enough benefits to out weigh the risk. At least with a 997 you get a better everything, mainly the interior and headlights.

groovzilla

How many miles on replaced engine?
-Get Bore scope Inspection & PPI (some on RL feel BS Insp thru oil pan removal is the way to go) - I disagree and have found going thru spark plug holes($250-$350)is a fine way to assess the cylinders as long as you have 2 good focussed photos of each cylinder.
-Review results and make a decision

Fined

If you get an OEM replacement part that is the same as the original, but the original had an engineering flaw then the OEM replacement part will also have the same engineering flaw. Unless you have documentation to prove otherwise for the specific part you're buying.
It would be very helpful for a buyer to understand the root cause of flaw of this magnitude and then this question provides it's own answer.

Petza914

The engine will have an AT in the engine serial number if it was replaced by Porsche, like M97/01AT68YXXXXX

A replacent engine will have the larger single row IMS bearing which doesn't usually fail (an 07 had this originally too) but the same piston and cylinder coatings as the rest, so it's not any less likely to score or have an ims issue than the original engine did

Charles Navarro

Very good point. I would want to see complete documentation for the engine rebuild and install. All that Porsche sells is a shortblock and the shop doing the swap would have to build the longblock. That's where things would get dicey. It's possible the heads were properly rebuilt and all the valvetrain components and other components that go into the longblock, but they might have been just reused from the old engine. That's why you need paperwork.

One place I would be concerned is if the injectors were reused (as they likely were not replaced) they often have gone bad and will wash down the cylinder bores. I know of at least one shop that put in a factory Porsche shortblock and reused the injectors and the same cylinder scored again within 3,000 miles.

As another poster mentioned, no improvements have been made by Porsche to their M96/M97 shortblocks. They are still susceptible to bore scoring.

Justin76

Charles, tried to send you PM but they are shutoff.. Can you click my build thread and answer a question for me. It's in my signature below..