About seven months ago I purchased a 2004 996 C4S (Manual transmission) with about 45k miles on it. Car is in FANTASTIC condition seemingly inside and out. I have had a couple of minor issues (sensors going bad) but what do you expect from a 14 year old car? Before I purchased the car I looked at the history of the vehicle. Biggest thing recorded was a clutch replacement at about 35k miles. Test drive went very well. I was shopping with a dealer I trust. (Used car dealership specializing in Porsche, BMW, Mercedes, Lexus - well respected and we are friends of the owners daughter and son-in-law).

First question I asked before buying was - "Has the IMS Bearing been replaced?" Answer was "No."

Ok so I buy the car, save up some cash and pay for the IMS Bearing replacement (and clutch while you are in there - might as well). I turned the car in last Tuesday. Thursday I get a call from the dealer and he says that the work was being done, they removed the engine to do the replacement and lo and behold there is no need for the IMS Bearing change. In fact, they look at the serial number of the engine and it turns out it is a Porsche 997 engine (Says 06-08 on the work invoice) in the vehicle.

So I am a bit confused. There is no record of this work being done. Ever. The dealer was completely unaware until they went to do the IMS Bearing replacement. While they were in there they checked and replaced the engine mounts, and the drive belt. The clutch is in perfect condition (as I kind of expected) so they didn't do that replacement after checking with me. They are providing me the serial number of the engine tomorrow. They literally charged me for the work "at cost". So the dealer made no money on the work they just did.

This leaves me with some questions:

1. Why was this done? Is there any way for me to find out? I suspect maybe a failed IMS Bearing or something else bad happened to the 996 engine and it was then swapped out.
2. Why was there no record of this work?
3. What does this do the resale value of the car? The 997 Mezger engine is widely considered to be a superior engine (?), but it isn't the original engine.
4. Are there any consequences to this kind of swap? Anyone familiar with potential problems meshing the two?

Thoughts?

 

Not a Mezger.

 

Sorry I thought all the engines in 997 were Mezger. I see my mistake now. Thanks. Still a 997 (M97) engine in there...

 

Previous owner might of replaced it out of pocket. Maybe a money shift. If PCNA didn't replace it and if there was no warranty claim it wouldn't show up in a CarFax. The dealer could tell you how many hours are on the engine.

BTW, not a Mezger. Mezger reserved for the GT3 and Turbo. The 997.1 (M97) engine is similar to the 996 (M96) but with a beefier, but non-replaceable, bearing. Much lower chance of IMS failure but it's not zero.

 

Thanks user 996AE above corrected me on that part - I was working under a mistaken thought that all 997s were Mezgers. Now I feel dumb for trying to sound smarter than I am :P

 

No worries.

Like others have said the 06-08 M97 engines are solid and overall better than the 996. While not a serviceable IMSB they are more robust, and you have more HP, Torque etc...

1-2% chance of IMSB failure? Not an expert but from what Ive read its pretty darn low.

VIN on engine may help you source it. Was it knew, rebuilt, from a salvaged 997? Service history?

Keep up posted. This is interesting.

 

Thanks for your help (and education). This is my first Porsche and while I did quite a bit of research in advance there is no way for a non-car person like myself to learn it all at once!

 

Have you looked up the engine serial to see if it’s a Porsche remanufacured M96 motor?

 

I'm getting the serial number tomorrow. Looking at the invoice it notes '06-'08 engine. But I will check once I get the serial number. Where WOULD I check? (if you know)

 

I'd have to see the engine serial number to possibly work out if the engine is truly a 997 engine.

My understanding is Porsche would not install a 997 engine in a car that came from the factory with a 996 engine.

I believe you are in the bay area? If so has the car been smog checked? It should have been before it was sold. It is the seller's responsibility to get the car through a smog check and that it pass.

As for your questions:

1) Who knows? Only the previous owner maybe unless he just had the car in and the engine got installed. Might surprise some here but some owners are pretty nonchalant about things like this. (And a few would have kittens...) If you can find out where the work was done you might learn why it was done. You might be able to deduce where the work was done by referring to a CarFax report. This report can list when and where the car was in for various things and this engine replacement might show up.

At least the CarFax report can (or may) show where the car spent some time and you can call various dealers in the area and with the VIN see if there is any record of the car being worked on. I did this when I was researching my 2003 996 Turbo. Avoid asking about previous owners. Focus on what work was done to the car. Maybe you'll end up talking to the place that did the engine swap.

For 2) There is a record somewhere, unless the shop that did the work discards invoices after so many years. Dealers do. Well, not discard but remove/file. My recollection is Porsche dealers only keep on file something like 4 years back at least on the dealer computer system. Parts department only keeps records for 2 years. I do not believe dealers destroy records but the paper ones get filed and stored and often times off site and are not really accessible to just run of the mill queries. If (big if) the engine swap was done under warranty of some kind the factory may have a record of this. Senior techs at dealers can access this database.

3) You just got the car and already you are worrying about resale value? Really at this time it is hard to say what if anything this engine replacement does to the resale value since it is not clear just yet which engine is in the car.

4) Well, one problem is the swap was not a Porsche sanctioned swap. IOWs, the car is a Frankenstein, so to speak. But before you lose any sleep on this subject wait and see if you can figure out if the car received a 996 engine or a 997 engine. It may just be the car is less a Frankenstein and more a "Six Million Dollar" car. "... Better than it was before. Better...stronger...faster ."

 

FYI, M96 factory crate engines(used to replace blown ones) manufactured in or after '05 have the same IMS as the M97.

 

I don't think its unreasonable to look at resale value on a car - even before you purchase it!

 

If this is the case - I wonder if thats not what I am dealing with. Seems likely.

 

I am in the process of replacing my blown 2000 996 engine with a 997S engine for big bucks...Consider yourself lucky you got it for free :-) Even though I had an LN IMS in my 996 engine, I lost the engine to oil starvation and lost a crank bearing. So you can lose engines for other reasons too. I would enjoy the extra power and just hope it was all done right. Cheers.

 

IMS - check! Now you can worry about the other 35 things!