Re: That serves me right for coming out of the shadows ...

I have a Boxster 03 S that I've owned since new. I recently had an Intermediate Bearing failure with only 25,000 miles. I have an opportunity to have a new 996 3.4L engine put in. Anyone tried this before? Any problems that would prevent this from being a reasonable solution? Thanks in advance.

This should provide the answers you need.

Pelican Parts Engine Swap Page

Without reading the link referenced above, I believe the 996 3.4 was an older engine with a throttle cable, and the 03 Boxster engine has a fly-by-wire throttle. I think that typically the first criteria for an engine swap is that you use the same throttle control mechanism. Thus I do not think the 3.4 will work in this case (at least not without rigging up a throttle cable). Look for a 3.6 engine from a 996.

If I am not mistaken, in addition to what jg atl mentioned, the DME's are completely different which takes considerable effort to wire around. Fortunately, the MY03 and later Boxsters have a DME that is compatible with all 3.6/3.8/X51 engines through MY08.

Bill

Patrick
Why do you say no for a 3.4? My guy says that it should work but hasn't done it before. This is an 07 3.4 brand new. I'm hoping it will work. Can you give me specifics that I can tell my mechanic(Porsche mech that moonlights) to look for? Thanks.

Ahh, if it is a 2007 3.4L, then it isn't a 996 3.4L (i.e. one with a mechanical throttle linkage) like you mentioned in your first post -- it would be a 987 3.4L (which has e-throttle), so at least that part is correct.

Now I can't remember if he said 996 or I thought it. But I didn't think they made a 3.4 for a 996 after a while. Only the new 987 box. But he said it was an e-throttle so must be a 987? Will that work?

MY2001 was the last year Porsche used a 3.4 liter engine in the 911/996. It seems to me to be a stretch that there are any NEW 3.4 liter 911 engines in existence. The engine you are writing about is a newly re manufactured engine. Possibly re manufactured by Porsche....possibly not. In any event try to get the serial number of the engine in question and post it here. Once you find out what you are dealing with you can get many of the questions you have answered.

Bill

The 3.4l engine you refer to is a much newer 3.4l engine, It is not the same as the 3.4l engine that was used in the early 996's.

However, the engine may work but to work the various systems much connect properly, to state the obvious. These include intake (with its e-Gas throttle), exhaust, fuel and coolant. Of course the engine hardpoints must agree with those offered by the car.

The above are relatively easy to deal with. They may not be that cheap/inexpensive to deal with though.

Where it gets tricky is getting the engine controller of the 03 car/engine to work with a several years *newer* more modern engine. The engine controller must be able to properly fuel the engine and manipulate the newer engine's various intake system and VarioCam Plus systems to derive full and reliable performance from the new engine.

Read the info provided at the link given above. I scanned through this the other day and it looks like the various combinations of older cars and larger/newer engines have been covered. I can't offer any estimate on how accurate the info is though.

It also helps to locate a shop that has done the swap you want to do and has done it successfully. I would prefer to seek out an owner who has gone through this and can vouch for the shop's ability to do a problem free swap.

Sincerely,

MarcW.

Thanks Marc
I've been assured that the engine does not have the vario cam plus so that will simplify things. The concoctions will fit but still I worry about the electronics talking to one another in the fuel management area. I'm trying to get the part # to make sure.

The issue isn't fit or bolt on compatibility, it has to do with the throttle.
I believe your car has the electronic egas throttle and the 3.4 has a cable.
You should verify what throttle that 3.4 motor has.
I'm sure with money and skill the 3.4 could be fitted converted to egas. Will the DME parameters set for your 3.2 motor work with the 3.4 motor? I don't know. Since your mechanic has not done this before do you want to provide him with this type of challenge on his first motor transplant?
If so I would suggest an upfront agreement on the total labor cost. I would not want to pay him on an hourly basis to deal with the learning and issues of his first motor transplant with complications.

It is not a vario cam plus. So that connection is not necessary. My mech says that he will check and see if the intake, exhaust match up enough. He says it is the same block so mounts will be the same. I do worry about electrically managing the throttle. I'll have mine towed over tomorrow and he can look at the match up. I'll see if I can get the serial number of the engine. thanks jp

If the engine is a MY07 3.4 liter Boxster S engine, I believe the serial number should look something like:

m97.21 67700501 -> m97.21 67760000

Where m97.21 = Boxster S engine (no IMS, with DFI),
6 = six cylinders,
7 = engine version,
7 = model year,
00501 -> 60000 = serial number of the engine.

If there is an "AT" between the 1 and the 6 in the serial number, that means the engine has been Porsche rebuilt.

BTW, a new MY07 Boxster S engine is P/N 987.100.920.04 and runs $27837.91 from your friendly dealer.

Bill

The DFI, non-IMS,engine came out with the 2009 model.

Lawdevil
2013 Boxster S - Agate Grey,
2016 Macan Turbo - jet black
Cashiers, NC & Atlanta

You are, of course, CORRECT!

That serves me right for coming out of the shadows.

Bill.

... just stay here where it's sunny and bright.
Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Bill
Here is the number the parts guy gave me on the engine I'm hoping to use. 986100924FX I can follow you on some of the numbers and meaning but looks like there is an FX that I don't know what that means. I got the car over to the guy today and he is going to take the tranny out to take a look at the connections.

In my case, the engine was better than the original, in that it had a properly centered crankshaft bore, and I'm sure it had more power, too. I checked wtih the dealer who did the job; also on the old PPBB, and it was a 2001 specification, 2.7 liter motor, nominally 217 hp. What surprised me was I was expecting the motor to feel tight and less powerful when I first got the car back, yet right from the get-go it had more oomph. As I was doing a break-in of sorts, i.e. not revving over 4500 rpm for the first 1000 miles, it was all the more astonishing that I could feel the difference in the lower range. From what I gather, the remanufactured engines are actually new motors that didn't meet the initial factory build quality, so they are rebuilt with special attention to tolerances.

986-100-924-FX is a part number not a serial number. Re. 986-100-924-FX

Part Number....................................Description....................................MSRP

986-100-924-FX.................... 3.2L 04- BOXSTER S M....................$16623.47

986-100-924-06.....................3.2L 04- BOXSTER S M.....................$29543.94

I don't know what the difference is between the two engines or the meaning of the "S M". One engine might be a new engine; the other a re-manufactured engine. In any event, engines with "-924-" in the part number are either MY03 or MY04 engines and are all 3.2 liters. A 3.4 liter engine part number starts with "987-".

I believe the code in the serial number to indicate a re-manufactured engine is "AT". Check out the following link:

[www.renntech.org]

Here is an example of an engine serial number (996 in this case): M96/03AT66567460

The M96/03 tells us it is a 3.6L 996 engine; the AT tells us that it has been rebuilt; as above the 665 means: 6 cylinder, 6 type of engine, 5 originally built in 2005; and the 67460 is just a sequence number.

I hope this is correct and that it helps.

Bill

my 02 Boxster. The price difference was simply the cheaper price was if I had an engine that would meet the core requirement and the higher price was if I did *not* have an engine that would meet the suitable core requirement.

Also, the prices I was quoted did not include labor to remove the old engine and install the new engine and any incidentals.

I was not aware that there was an AT in the serial number if the engine was remanufactured. My info -- and I can't recall where I got this -- is the serial number has an 'X' at the end. IIRC my Turbo's replacement transmission had an 'X' at the end of its serial number and I know the transmission was a remanuactured one. I'm away from my full library of pics right now so I can't search them for engine or tranny serial number pics.

Sincerely,

MarcW.

I think I know what happened to cause this confusion. I asked the service guy who asked the parts manager to find out the serial number of the 3.4 engine. That was not passed and the parts guy naturally assumed I wanted a replacement for the engine that I had in the car. So that is the number he gave me. I didn't know enough about it to ask the question until now. So I will re-attack and see what I can find out. I din't think my mech would make a mistake like confuse a 3.2 with a 3.4. More to follow.