Is a replacement engine a bad or good thing?

So here is the issue. There is a 2002 996 that runs perfectly (in fact better than new), but keeps having a leaky rear main seal. The car has 40,000 miles on it, but the rear crankcase tolerance where the RMS goes is out of specification and continues to leak. Because of this, the car will get a replacement engine and an extended warranty courtesy of Porsche. My gut tells me this is a good thing as the chassis is tight, the rest of the mechanicals have been faultless, and the transmission is perfect. With a remanufactured engine, it seems like the car would be good for at least another 50K miles, but that this engine will need to be broken in again. What is the consensus on this situation. Replacement engine good? or Replacement engine bad?

I think it is no problem for either you to keep it or for a prospective buyer to evaluate it. New mechanicals and extended warranty...what could be wrong with that?

Comparetively speaking anything would be better than the engine that's in the car right now. Since Porsche is replacing it with a reman. unit there is no need to break it in, as they do that at the factory. Good luck!

I had a replcement due to a non-RMS issues (they still don't know what happened, or haven't told me but the engine let go -- I think it had a slightly cracked block when I got it from the Porsche dealer, but what do I know). I was very happy with the process and I am very happy with the results as I noticed it running much better. My new engine (according to Porsche NA, as I called them) was 100% new internal and external parts, and only the block was remanufactured. Apparently this is a typical approach? And yes, it is all broken in and all by the factory. However, I still took it easy for the break-in period. I personally think this would be a very good thing for overall performance and resale, but welcome other opinions.

it could be that an RMS leak is a manifestation of misaligned transmission.... that new motor going in will no doubt have ANOTHER RMS leak.... personally I wouldn't buy a car with a new motor. If your car has RMS.. I don't think changing the motor will do any good... it will show its ugly head again.

Help me understand what you mean by a misaligned transmission and how that could cause an RMS leak.

A while ago and I read this here on rennlist... a porsche engineer suggested that the RMS leak is a manifestation of another physical problem in the motor.... and this problem would be a misaligned transmission -> beyond that I cannot explain nor understand the mechanism by which this incurs more RMS leaks... but from observation on this board... if you had one RMS your getting it again... also if your engine has NEVER had RMS before 40,000 miles, chances are everything is ok and you will never see it. (IMHO)

I thinks its a good thing. Good warranty, 'new' engine...what do you have to loose?

at the factory... the specialize at putting in new engines... don't know how good a local dealer will be cause they don't do it all the time... know somebody who has a replacement motor and there are still problems...

I got a reman engine also and posted the same question elsewhere. The consensus was it is a neutral. I have 1500 miles so far and no oil burning which was the reason for the change. I am happy thus far. Took it easy during the first 1000 miles or so and even a little now.

Having had a fresh unit put in by Porsche after 30K original miles, no oil leaks and perfect running make this a no brainer. Completely painless with nothing but a new, better motor.

If you keep the car yourself for a few years, a remanufactured engine should be a good deal for you. When you sell it, it may hurt your resale value because there are some Porsche buyers who won't buy a car with a remanufactured engine. Of course when selling, you could play dumb like many car dealers and claim that you have a new and not remanufactured engine.

My 2.5L Boxster engine was replaced at 45k mi with a remanufactured engine. My understanding is that "remanufactured" engines are new engines that failed factory bench testing and were sent back to the line for correction. These engines are again tested and then used for warranty purposes. My replacement engine was much stronger than the original. It pulled harder. I put 16k mi on it before selling it, with not one problem and no oil usage. The person who bought my car considered the newer engine a plus, not a negative. There were potential buyers who were concerned about it however. As for break-in, my SA told me the replacement engine was run-in at the factory, and to just keep the engine below 5200 for 500 mi or so. If the engine in my 99 Cab failed today, and I got a new (remanufactured) engine it wouldn't bother me in the least, and I would probably keep my car longer due to the fresh engine and two year unlimited mile warranty that comes with it. YMMV.

if you are worried about placing well in the pebble beach concours then mismatched numbers will be a negative for you can they tell you how many miles are on the remanufactured engine? are remanufactured engines essentially used engines brought back to the factory for rebuilding or are they new, straight off the line and put back in the line due to quality issues? at any rate, a remanufactured engine should have been checked to be within tolerance and theoretically should not leak as your current engine does.

I was going to have a little plate made with the original engine S/N on it to place over the remanufactured engines number. That should get me through Pebble Beach OK. The other plus here is that with the engine out of the car, I can clean and wax the inside of the engine bay much easier than with the engine installed.

It wouldn't bother me in the least.

lol! sheesh! how can you get you engine any cleaner? i've seen pics or your engine and it is spotless. no cosmoline, grime, etc can be found.

As a former Toyota guy and a new owner of a C4 it's really hard for me to believe that you guys think these sorts of problems are acceptable. I suppose most of you figure there isn't much to be done, but that an engine would only last 50k before replacment is a very foreign concept to me. I guess I was spoiled when I hit 200k miles on my turbo charged Toyota engine and neither burned nor leaked oil...I'm sure I'll get a response or two suggesting I go back to Toyota if I love it so much and I'm not here to bash the 911 (as I said I'm a new owner), but it's just strikes me as odd what people are willing to accept and hear from their dealer of a high end car. PS--I just replaced my RMS last week.

FWIW, my old engine was .05mm out of spec; therefore, it would be impossible for Porsche to stop a potential RMS with that data. The first motor ran fine. There solution was to give me a new motor, since the remanufactured ones were all out as my car was on the lift at the dealer. BTW, Toyota consultants are the reason we have M96 engines that are so cheap to build as compared to the 993 motors. It is Toyota's fault.

I don't think rear main seal leaks are that uncommon among any engine, especially aluminum block ones. I had a 300Zx that had this exact same problem and had to have its RMS replaced 3 times. Ford just recalled all of its Ford GTs because of this problem, and there are other aluminum engined cars that have had this issue as well. I think that these Porsche engines with the RMS leak would easily run 200K just fine except for this leak. My car is very strong, except it leaks oil. Toyota has some very reliable engines, most are cast iron blocks and by the nature of the type of material used, tend not to have as many RMS issues like these. I think that Porsche has done the right thing with stepping up and replacing the entire engine module is need be. I don't know if this is widely known, but all products such as cars have a warranty cost of service built-in to the price that a manufacturer sells its product for. So part of the premium we pay for these cars is used to pay for these warranty claims.

Just came back from Stevens Creek Porsche, and they already had a replacement engine ready to install. The old engine looked like it was leaking pretty good. The IMS seal looks like it has been redesigned on the new engine, and I would hope that the RMS hole in the crankcase is machined better this time. The car is expected to be ready tonight, so we will see how it goes.

It is a thing of beauty, though, isn't it?

The engine on my 03 C2 was replaced 2 weeks ago (19K on original engine). So far the car is running great.

The car came back yesterday with the new motor installed, and there are several subtle differences in if from my other M960 engine. First off, the part description for the motor is "L 05 996 Carrera" which describes a motor for a 2005 Carrera. This is good. I saved the build sheet that came with the motor, and it has an assembly date of March 11, 2005. The Part number of the engine indicates that this is an engine for exchange, but the S/N of the engine does not seem to indicated that this is a rebuilt engine. Does anyone know what field in the Engine Serial Number indicates a new or rebuilt engine? The other thing I have noticed on the new engine is that all of the fastener bolts have torx heads on them instead of hex heads. When the engine was installed, the old air conditioning compressor, catalytic converters, mufflers, and surprise, the serpentine drive belt, were moved over to the new engine. It came from the factory with a full sump of oil. The starter now sounds like a Ferrari starter, kind of a small high pitched whine when it starts. Performance is good, and the VarioCam surge is completely gone. This was an annoyance on the old engine. The engine was already broken in on a test bench, so I would hope that this one will be solid. I'm gonna change the oil at 45K miles to get the maintenance of the engine in sync with the car. Stevens Creek Porsche and their crack team of Porsche mechanics did a great job doing the swap.

I'm confused. Isn't an '05 Carrera a 997?

There are still some 05 996s being made, like the C4s, and doesn't the regular 997 Carrera still have the M960 engine in it?

I believe that there is an "X" or something of the like behind the serial number of a remanufactured engine. When I had my engine replacement, I got the same thing save for mine was 04 (My build date was 1/19/04 - which coinsidently, is my birthday). There was a bunch of changes made to these engines in the design and casting especially it seems. I'm surprised that you don't have the vario cam surge, I still do, but that might be the difference between the L05 and L04. I've gone one year with no further problems (leaks). I wasn't holding my breath for a time, but I think things are going to work out. Looks like no further oil drop tattoos for me. PS Mine is not remanufactured, I actually got a brand spanking new motor.

Can you see the number anywhere w/o dismantling the car?

Old Motor (QUIZ - Anyone notice anything else wrong in this picture besides the oily residue around the crank?) New Motor

I believe so...put your car on a lift...and I think it's on a flat piece somewhere on the drivers side. But, I'm sure it's elsewhere as well.

No the engine serial number does not have an "X" in it.

The case halves are 2 different types of castings. one has a crosshatched surface and the other does not, plus they are a different color.

is it the M96/03XXXXXXX? If that's the case, I'm looking at an 03...but the castings match

Yup, I was told by the Service Advisor that 997 motors are not compatible with 996 ECMs, FWIW.

That is correct, but the 05 996 cars that are (were) being produced had the same engine as the rest of the 3.6L cars from past years.

Gotcha. You probably got a new one, also. When mine got changed, it had the updated thermostat body and they were out of rebuilt units from the remanufacturing facility in Ontario, CA (MAY '05). They flew it in from Germany, supposedly. My old casing # was M96/6-------; so you didn't get that one.

Also, my service receipt specifies "996-100-995-DX 3.6L 05 996 CARRERA......(N/C) [No Charge]" for added curiousity.