Engine identification

[Gus969]

I have a 1997 Boxster converted with a 3.4 liter engine.

My serial number on engine is: M96 / 0166X14690

Can anyone tell me year of MFG?

[Loren]

66X would say it was made in 1999.

[jdlmodelt]

is there a thread here that clearly and accurately explains the engine serial number decoding? My 99 got a new engine in 2008, the replacement engine S/N: M96/20AT65X65895, can anyone tell me what all these numbers mean?

thanks,

James

[Loren]

For 9x6 series engines:

(click to enlarge)

Porsche's PET parts system has more information but the list is maybe 20 pages long (too long for here)

For your engine M96/20AT65X65895

2.5 liter Boxster engine - 65X says the engine was manufactured in 1999 and was rebuilt at a later date.

The re-build date is not in the serial number but might be in the car's service records.

[jdlmodelt]

Rebuilt by Porsche? It was installed in 2008 on a 99 base boxster after the original engine came apart.

[Loren]

Rebuilt by Porsche? It was installed in 2008 on a 99 base boxster after the original engine came apart.

Yes, the AT designates a factory rebuilt engine.

AT is short for Austausch, German for Exchange.

[jdlmodelt]

Okay, thanks! I take it there is no way of knowing what year it was rebuilt?

When the factory rebuilds a 2.5l, what do they do with regards to all the new engine factory tolerances? i.e. cylinder bore, rods and mains?

[JFP in PA]

Okay, thanks! I take it there is no way of knowing what year it was rebuilt?

When the factory rebuilds a 2.5l, what do they do with regards to all the new engine factory tolerances? i.e. cylinder bore, rods and mains?

All "AT" engines are to the original factory specs, particularly as there are no over sized rod or main bearings available for these engines.

[jdlmodelt]

Are they able to resleeve the cylinders? Or is the engine case just junked of there is cylinder damage or excessive wear?

[JFP in PA]

Are they able to resleeve the cylinders? Or is the engine case just junked of there is cylinder damage or excessive wear?

That obviously totally depends upon what happened to the engine during the first failure, some cases can be salvaged, some not. But all the "AT" engines are recycled used cases.

[Hilux2400]

I have a similar situation with an "AT" engine. My car is a 2003/996 and the engine dates from late 2005 and possibly put in the car in early 2006. There was no record in the V5 and neither do Porsche have any records other than the number of the engine that was in the car at the time of manufacture.

I did not know any of this when I bought the car it was only after asking questions on this site and getting answers from Loren and JFP that things became clear.

Great site with some clever and knowledgeable people about.

H