Great story and great support from your dealer!

 

" I was talking to one of our top local Porsche mechanics the other day about extending my warranty... In the discussion he said the 2004 C4S was the most common car he's seen with IMS failures. Didn't know why. " Interesting comment on the 04 C4S....sounds pretty fishy. Consumer Report Use Car Guide reports the 04 996 as having the best reliability record of the 996 production line. We should ask if track days increase engine failures. Why would a 996 04 C4S be more prone to engine IMS/engine failure. The 03 enhancements to the 3.6 cams, pistons, variocam etc should make it more "reliable" not less per your mechanics "observations". No one wants to be replacing engines to the tune of 15 K if out of warranty. Is there anything one can do besides change the oil at 5K (5W-40), not track the engine, run the car regularly, not lug the engine , shift properly, etc to avoid the dreaded replacement engine. And of couse the briliant statement "run it like you stole it" all the way to the dealer for your engine swap.

 

Time for you to buy a lottery ticket...

 

I certainly track my vehicle. Not sure why that should make such a difference between years (but may make a difference between models - the air-cooled model's IMS seem to be very reliable by comparison...)

My perspecitve is that these engines have been designed to be run hard. With the # of water-cooled porsches running at the PCA events I attend it strikes me as a bit more of "bad luck" with a known failure than specfic causality.

Replace "Porsche" with almost any other manufacturer - like Chevy (for Corvette.) In 2008 we had 2 corvette engines (both current models) disintegrate on-track in 1 weekend. Both were driven by very experienced drives. One was right on the pit staight @ Mid-Ohio. Very exciting - fireball-type fireworks & parts being shot everywhere. We went out to collect parts for 15 minutes. Can you imagine the discussion with GM in getting warranty coverage on this "event"?

 

IMS Failure:

When mine goes out I will have it towed to Sewickley!

99C2

 

I didn't think the air cooled engines used an intermediate shaft?

 

They do.

 

As I comb through my poor old brain, it occurs to met that the difference with the M96 is not that it has an intermediate shaft, but that the shaft is unsupported at one end (and much longer).

 

Basically the aircooled 911 has the same shaft to drive the valve train as the M96, but we refer to it as a "lay shaft" most of the time.. The 547 4 cam Carrera engine also used the same style of layshaft but equipped it with bevel gears to drive the exhaust cams.

Here is a pic of a layshaft from a Carrera engine from my 4 cam archive


The biggest difference lies in the fact that all the predecessors of the M96 use a plain bearing to support the layshaft (IMS) instead of a roller bearing, like the M96.

 

Jake, I think saying the "same shaft" is oversimplifying it. People would be misled to believe that Porsche used to make good intermediate shafts and then made bad ones. They made a fundamental design change, it seems to me, from a short intermediate shaft supported by bearings at both ends, to a long intermediate shaft that floated at one end. That's what strikes me as the biggest difference. And, frankly, it was understanding that difference that sold me on your product.

(Images poached from Renntech)

 

what is #28 ?

 

What a great story. If my 996 ever experiences this much-discussed situation, I plan to make the same conversion to the X51.

 

"I certainly track my vehicle. Not sure why that should make such a difference between years (but may make a difference between models - the air-cooled model's IMS seem to be very reliable by comparison.". The 03-04 996 models got new crankshafts, new pistons and new connecting rod's. Not sure if any of these would decrease the engine swap. Jake, if given the choice to choose a model year for the 996, which would you choose based on your experience?

 

Just a guess: as far as IMS is concerned, all 996 and Boxters line up for failure statistics.
My 02 C4S is fine at 94 Km.

 

Congrats on having a stupendous dealer! The one here seems good and while I sure don't want to test HOW good I'm happy to hear that your diligence and loyalty was rememebered and recognized!

What's the name of the Dealership again?