Causes of M97.21 Engine Failure?

[Krokodil]

The engine in my 2007 Cayman S failed this past weekend while on track. It lost power, began to vibrate, displayed the CEL and low oil pressure warnings, and began to clank. The engine has 46K miles on it, including 5000+ on the track.

While the engine is not yet completely apart (should happen today) the initial inspection showed connecting rod bearing material in the oil pan. Other parts may have failed as well, but this is what we know for now.

Our path forward is not yet clear. We can install an OEM remanufactured engine, buy a local used engine, our more than likely rebuild the existing engine (if possible) with stronger parts (Carrillo rods, etc).

So, the question for those of you that have been through this with either the M97 or M96 engine is what else fails and should be strengthened during rebuild? We know there is an IMS issue, but what else?

Please do not tell me to remove my track parts, take it to the dealer and lie about what happened. This is not how I work. I raced the car and violated the warranty plain and simple.

List of failures, strengthening needs:

1) Connecting Rods

2) IMS

3)

[1schoir]

The engine in my 2007 Cayman S failed this past weekend while on track. It lost power, began to vibrate, displayed the CEL and low oil pressure warnings, and began to clank. The engine has 46K miles on it, including 5000+ on the track.

While the engine is not yet completely apart (should happen today) the initial inspection showed connecting rod bearing material in the oil pan. Other parts may have failed as well, but this is what we know for now.

Our path forward is not yet clear. We can install an OEM remanufactured engine, buy a local used engine, our more than likely rebuild the existing engine (if possible) with stronger parts (Carrillo rods, etc).

So, the question for those of you that have been through this with either the M97 or M96 engine is what else fails and should be strengthened during rebuild? We know there is an IMS issue, but what else?

Please do not tell me to remove my track parts, take it to the dealer and lie about what happened. This is not how I work. I raced the car and violated the warranty plain and simple.

List of failures, strengthening needs:

1) Connecting Rods

2) IMS

3)

Croc:

Sorry to hear that your engine gave up the ghost.

Take a look at Jake Raby's site for some solid suggestions: http://www.flat6innovations.com/

Also check out LNEngineering.com.

Both sites contain a wealth of information on possible upgrades.

Regards, Maurice.

[berty987]

Not sure how you can cure or improve the IMS issue, the cayman already has a larger bearing and shaft fixing diameter. The root cause is that there is only one bearing taking all the load , so if it weakens then the deterioration is quick. Strengthened con rods should be available from 9ff or Ruf , I believe they developed their own for some of their hi performance models. Good luck with the rebuild please keep us updated with the improvments and mods applied, especially if you find something for the IMS.

[Brad Roberts]

I have a 3.4 CaymanS apart right now (actually I have multiple M96 and M97's apart right now) You may know the engine :) It is the last one that was in Quinn's car here in SoCal. His car broke a rod bolt and let the rod cap fly around inside the engine. Now, the question is: How did that rod bolt break? I do not have access to his car, if I did, I'd check the range 2 overrevs looking for a mechanical overrev :(

We do have aftermarket rods/pistons/cranks/intermediate shafts available currently (I work VERY closely with the two companies mentioned above)

I received a phone call from the track within minutes of your engine expiring and I was making an effort to track you down and ask you what happened. I'm working on stocking dyno tested upgraded M96 and M97 engines for shops here in SoCal :) We are well on our way to providing people with a solid solution to these engine issues (and come in well under what the factory wants for a *questionable* replacement.

Is this a BBI car or a Essa car? Or Vision? or Speed Gallery? I'd like to see it the engine apart.

B

[Brad Roberts]

Here is Quinn's old Cayman engine :( I have NEVER seen a piston split like this and I have building Porsche engines for nearly 23 years now. You can see in the second pic how the rod damaged the engine case while it was being thrown around :( That is a small hole to the bottom right of the cylinder where the rod bolt exited the case.

B

Edited February 14, 2009 by Brad Roberts

[Brad Roberts]

Oh.. FYI: the M97's will not see the IMS failure the early M96's have experienced. Porsche went from a 5 chain cam drive system to a 3 chain. This took some of the stress off the IMS. They also beefed up the IMS rear bearing and support. They also used much much better material for the actual shaft itself which means less twisting :)

B

[Krokodil]

Oh.. FYI: the M97's will not see the IMS failure the early M96's have experienced. Porsche went from a 5 chain cam drive system to a 3 chain. This took some of the stress off the IMS. They also beefed up the IMS rear bearing and support. They also used much much better material for the actual shaft itself which means less twisting :)

B

Brad,

Thank you for the photos and information. Yes, I know the engine and was there when it failed. According to Quinn there were significant high-range overrevs, so many that he doubts the accuracy. I assume it was quinn that called you from the track.

The car is at Vision and the engine was set to be torn down yesterday. There was bearing material in the pan and oil filter, but I do not know any more beyond that.

I assume if you contact Dwain he will share his findings with you, and vice versa. I hope to visit the shop on Monday PM.

Cheers,

[Brad Roberts]

Thank you sir! I'll speak with Dwain later next week. I'm heading to Texas to deliver a Porsche. We are just trying to gather as much info about failures as possible!

B

[berty987]

Oh.. FYI: the M97's will not see the IMS failure the early M96's have experienced. Porsche went from a 5 chain cam drive system to a 3 chain. This took some of the stress off the IMS. They also beefed up the IMS rear bearing and support. They also used much much better material for the actual shaft itself which means less twisting :)

B

I have seen a couple of IMS failure posts on 2006 > cayman engines , so though it may have reduced the risk , I still do not think its completely cured.

[Brad Roberts]

I meant to respond to this :) Can you point me to the threads were people lost IMS in M97 engines?

Thanks!

B

[berty987]

I beleive it was in the boxster forum a 2007 2.7 unit failed.

[Krokodil]

The car is alive again. Fired last Friday 3/20 and was racing Saturday AM at WSIR.

The diagnosis was a failed #1 rod bearing, resulting in a broken craddle, two broken cases, a broken, rod, a couple of bad pistons, etc.

We purchased a used Cayman engine (from a 3.8 swap) with just over 2000 miles on it (Brad, you apparently know this engine) to use as a rebuild donor. Several chnages to improve oiling and reliability including a modified crank and installation of Carrillo rods:

Cheers,

Edited March 27, 2009 by Krokodil

[caymanquest]

I am a new member and thought this would be the right place to post this question. I have a 2006 CaymanS with 12,500 miles of normal street use. The engine was burning lot of oil and the engine light came on a couple of times. Finally Porsche agreed to inspect it and reported the "left bank cylinders were scorched" and the engine was replaced. I am reading posts about other types of engine failure but I have not seen this?

[01vdpsc]

Oh.. FYI: the M97's will not see the IMS failure the early M96's have experienced. Porsche went from a 5 chain cam drive system to a 3 chain. This took some of the stress off the IMS. They also beefed up the IMS rear bearing and support. They also used much much better material for the actual shaft itself which means less twisting :)

B

Did this happen with the m97 motors only or did some of the 996 motors have this as well?