M96 and M97 Confusion

[Hilux2400]

 

Merci, J-F for your fast triggering on this beautiful Friday afternoon!

So, even an 05 'S' could have a smaller diameter, singe-row IMS bearing, n'est-ce pas?

Martin

 

Correct, but take a lesson from another recent poster here that had a 2004 996 C4S which should have been a smaller and replaceable IMS bearing, so he went out and purchased everything he needed to do the IMS swap, including the LN bearing kit.  But when he took the car apart, he found the oversized non serviceable design bearing in the engine, because the engine was a factory replacement (bore an engine number with "AT" in it, which stands for "Austauschmotor" or replacement engine in German), leaving him stuck with the expensive LN kit, and the car all apart: 

 

 

When you are looking at these cars, particularly with the intent of buying one specifically to do an IMS retrofit, you really need to understand what you are looking at or you can make an expensive mistake.  In the case of an 05 car, if it still has the original engine in it, it could still go either way, and you need to pull it apart to find out what you are dealing with.

 

One day I will know the answer to this question for my 2003/C2 car which had a replacement in 2005 sometime and now has the engine number:

 

M96/03AT 66566759

 

Mine's only 1,201 units apart but slightly earlier.

Edited May 23, 2015 by Hilux2400

[Y2K911]

Thanks J-F!

So the hard lesson is 05,s can't really be trusted IMS-wise, even 'S's ... and watch that AT or austauschmotor designation, which will likely mean it did receive a larger single-row IMS during that replacement build or rebuild.

Forewarned is fore-armed as a potential 997 buyer!

[j_beede]

Thanks J-F!

So the hard lesson is 05,s can't really be trusted IMS-wise, even 'S's ... and watch that AT or austauschmotor designation, which will likely mean it did receive a larger single-row IMS during that replacement build or rebuild.

Forewarned is fore-armed as a potential 997 buyer!

 

I'm not sure what you mean by fore-armed... How many MY05 buyers have the transmission pulled as part of the PPI? If you were selling a 997 would you approve the prospective buyer having the transmission pulled in order to inspect/identify the IMS bearing?

[Y2K911]

Good point!

I meant 'fore-armed' from a buyer standpoint whereby, I would likely opt for an 06 rather than an 05 to stay away from the IMS unknown risk parameter. With respect to your last question as a seller, I would not agree to go as far as pulling the T-mission but I would be honest enough to tell the purchaser about which type of engine the car has: original, refurb such as AT, etc ... to the best of my knowledge.

Edited May 27, 2015 by Y2K911

[JFP in PA]

Good point!

I meant 'fore-armed' from a buyer standpoint whereby, I would likely opt for an 06 rather than an 05 to stay away from the IMS unknown risk parameter. With respect to your last question as a seller, I would not agree to go as far as pulling the T-mission but I would be honest enough to tell the purchaser about which type of engines the car has: original, refurb such as AT, etc ... to the best of my knowledge.

 

One of the things a good PPI does is to record the VIN and the engine numbers, and check the latter to see if it makes sense to the car (year, displacement, etc.), as well as checking to see if it is a replacement.  Not that long ago, we had an immaculate 996 in the shop for a PPI, which turned out to be carrying a 2.7L Boxster engine.  Needless to say, the sale did not go through.

[Y2K911]

Wow! Thanks for sharing this nugget of deviousness, JFP. Forewarned, indeed!

[gsmiller]

Following up on the earlier points related to water pump interchangeability between the M96 and M97 engines: Today my mechanic changed the water pump on my 2004 C4S.  The water pump on the engine looked to be original by the way the metal housing matched the engine.  When he pulled it off, it turned out to be a 997 part.  He replaced it also with a new 997 part.  Can anyone confirm if the 997 part truly fits my M96.03 engine (code appears to be M96/0366408776)?  Does it make any sense that the factory would have installed a 997 part on the engine, or is it not likely the original water pump?  My mechanic's theory was that the engine was replaced in the car, and that there was a transitional phase where some 997 parts were used on M96 engines.  Thoughts on this theory?  Would love to get to the bottom of this.  Thanks!

[Loren]

Following up on the earlier points related to water pump interchangeability between the M96 and M97 engines: Today my mechanic changed the water pump on my 2004 C4S.  The water pump on the engine looked to be original by the way the metal housing matched the engine.  When he pulled it off, it turned out to be a 997 part.  He replaced it also with a new 997 part.  Can anyone confirm if the 997 part truly fits my M96.03 engine (code appears to be M96/0366408776)?  Does it make any sense that the factory would have installed a 997 part on the engine, or is it not likely the original water pump?  My mechanic's theory was that the engine was replaced in the car, and that there was a transitional phase where some 997 parts were used on M96 engines.  Thoughts on this theory?  Would love to get to the bottom of this.  Thanks!

 

The 997-1 engine uses many 996 (3.6 liter) engine parts - and yes, the water pumps are interchangeable.

Very little difference between the 996 (3.6 liter) engine and the 997-1 (3.6 liter) engine.

 

The 996 and 997-1 were both produced in MY2005 so if your car was a late 2004 car then a few 997-1 parts would not surprise me.

In most cases the parts are en evolution and better quality or durability, or even better cost margins. 

[gsmiller]

Thanks Loren; super helpful!  I've been searching for a while tonight trying to get to the bottom of this.  I'll check with my mechanic tomorrow if he had to snip the gasket since I'm really curious if the factory installed the 997 part or if it was done at some point. 

[Ahsai]

Thanks Loren; super helpful!  I've been searching for a while tonight trying to get to the bottom of this.  I'll check with my mechanic tomorrow if he had to snip the gasket since I'm really curious if the factory installed the 997 part or if it was done at some point.

Just call Sunset Porsche parts department and give them your VIN. They can tell you with certainty if that part is meant for your car.

[gsmiller]

 

Thanks Loren; super helpful!  I've been searching for a while tonight trying to get to the bottom of this.  I'll check with my mechanic tomorrow if he had to snip the gasket since I'm really curious if the factory installed the 997 part or if it was done at some point.

Just call Sunset Porsche parts department and give them your VIN. They can tell you with certainty if that part is meant for your car.

 

That's a good idea.  Thanks!

[gsmiller]

Well for anyone that's curious, I did check with my mechanic today and the 997 pump was in fact original on my M96 engine (the gasket hadn't been snipped and the markings on the engine housing and pump matched far too well to be a replacement).  So there you have it: 997 pump factory installed on a late 2004 M96 3.6L motor.

[kgoertz]

That is very interesting.  I had to return a 997 water pump that was incorrectly ordered for my 2002 996 since it clearly didn't work.  It looked identical but the impeller was slightly (measurably) larger and wouldn't turn once I had it on the block.  I wonder when they made the change to the block to fit the slightly-larger impeller.  That's confusing.

[Ahsai]

AFAIK, the 997 water pump's diameter is a little bit larger than the 996. In fact, one 996 owner once fitted a 997 pump and hand spun it and he could feel the blade scrapping the engine block. He switched out to a 996 pump and problem solved.

 

Would be nice to see if a new 997 pump spins freely in your engine case. If it does, that's a further proof that's the right part. Again, a simpler and more direct way is just to call the dealer.

[Ahsai]

That is very interesting.  I had to return a 997 water pump that was incorrectly ordered for my 2002 996 since it clearly didn't work.  It looked identical but the impeller was slightly (measurably) larger and wouldn't turn once I had it on the block.  I wonder when they made the change to the block to fit the slightly-larger impeller.  That's confusing.

 

Ah, maybe you're the one I was thinking about :) You got your pump from ECS tuning, right?

[kgoertz]

 

That is very interesting.  I had to return a 997 water pump that was incorrectly ordered for my 2002 996 since it clearly didn't work.  It looked identical but the impeller was slightly (measurably) larger and wouldn't turn once I had it on the block.  I wonder when they made the change to the block to fit the slightly-larger impeller.  That's confusing.

 

Ah, maybe you're the one I was thinking about :) You got your pump from ECS tuning, right?

 

Guilty.  That was me :)  Great memory!

 

I had posted a detailed writeup on the differences in the water pumps on Rennlist.  I apologize in advance if posting a Rennlist link is frowned upon.

 

http://rennlist.com/forums/996-forum/796545-new-water-pump-installation-pump-not-spinning-freely-997-pump-in-a-996-a.html

[Ahsai]

Cool, so I'm not crazy haha

 

If you look at the autoatlanta site http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=996-99-05&section=105-00

you can see that the 997 pump can fit M96.03 engines but only from '05 and up. I suspect the OP's '04 is at the transition year so it's possible it got the 997 pump from the factory.

[JFP in PA]

I would also go under the car and read the engine number, looking for the letters "AT" in the engine number sequence to be sure if it is the original lump or a later version.

[uomoconle00]

Hello everyone and happy holidays

I have a 996 cabrio 2001 in which another engine think how can I verify that type of engine has been mounted it?
I have a serious problem does not rise revved stops above 5000 rpm and then you have to turn off and on to make her walk, as if it lacked gasoline drowns and tends to fade
we can not understand what he
sometimes even the tip tronic no signal right gears on the dashboard while mechanically goes
What could I do to check the exact engine model?
What could I do for the failure of acceleration?
It states that there is no symbol on the block to make me go back to the kind of precise engine

[JFP in PA]

By looking for the engine number shown in the photos above, plus a 2001 car would have come with an M96 variant.

 

To address the acceleration problems, you need to take your car to a Porsche specialist for diagnostics.

[Edgy01]

On 6/4/2012 at 10:54 AM, Loren said:

No, the 3.8 liter engine uses the same water pump as the 3.6 liter.

Some bad some bad information being put out here.

 

the Carrera S with the 3.8 engine, aka M37, has a larger water pump than the 3.6 litre engines (M36).  When Porsche produced the larger S engines they up sized the water pump because it was needed.

 

dan

[Loren]

6 minutes ago, Edgy01 said:

Some bad some bad information being put out here.

 

the Carrera S with the 3.8 engine, aka M37, has a larger water pump than the 3.6 litre engines (M36).  When Porsche produced the larger S engines they up sized the water pump because it was needed.

 

dan

 

Of course, you mean M96 and M97 engines - since there is no M37 and M36).

And Porsche's part list (PET) shows the same water pump for 996, 997-1 3.6 liter and 997-1 3.8 liter.