Are 996 motors disposable or rebuildable?

[guthrie]

Are the 3.4 and 3.6L watercooled motors designed to be rebuilt or simply replaced if a cylinder is "dead"? I performed a compression test on my motor and 5 cylinders delivered about 250psi and the last cylinder averaged 40psi!!! I repeated the test with the same results. The bad cylinder is number 4. I would like to take the motor out and tear it down and rebuild it with new rings. I am targeting rings because the leak down test didn't show any problem with the valves but did show problems with the rings. Additionally I am getting tremendous amounts of oily smoke out of the air oil separator, exiting out of the hose that returns vapors back to the intake manifold. The hose resembles an old locomotive chugging away.

[Loren]

Reliability of 996 Engines

Be sure and check the photos of the tear down.

[guthrie]

Reliability of 996 Engines

Be sure and check the photos of the tear down.

Loren,

Thank you, I looked over the pics and began to read the article. Do you know if there are special tools that are need to split the crank case and deal with pulling the pistons? Additionally, any special tools to put it back together again? Is this a DIY adventure?

Thanks

[Loren]

That will depend on what you need to do.

The camshaft positioning tools are helpful when re-timing them.

Otherwise I think most of the tools are standard engine building tools (i.e. piston ring compressors, circlip tools, etc., etc.).

[smartrepair]

Reliability of 996 Engines

Be sure and check the photos of the tear down.

Loren,

Thank you, I looked over the pics and began to read the article. Do you know if there are special tools that are need to split the crank case and deal with pulling the pistons? Additionally, any special tools to put it back together again? Is this a DIY adventure?

Thanks

Hi

I did the rebuilding of a 3.4 engine by myself. I have no previous experience on those things, but had the Porsche workshopmanual. Without it it would have been impossible to do it.

The only "special" tool required was a home made piston circlip installation tool, which I made from two plastic tubes. See attached picture. I cannot remembre the diameters of the tubes, but I think the bigger one was about 3/4", and the inside one was just able to slide inside. I had to sand away a bit for the exterior tube for it to enter the piston installation hole.

I looked the exact position of the circlip, and made a blue line into the "installation tool" to be able to line it correctly to the piston. The small cut you can see in the exterior tube is where the circlip´s hook has to be placed. It was a bit problematic to put the circlip inside, but I found out that even it was not completely perpendicular to the tube, it went into it´s place without problems. Just a light hit to the inner tube, and the circlip went into. Just press the exterior tube tightly against the piston.

I was surprised how easy it was,in the end, after months of investigation how in heaven I´m going to get the circlips in....

When I opened the engine, I removed the cams together with the variocam unit, so here was no need to adjust them. The chains were OK. I also made a small thing to hold the cams inplace when the valve cover was removed.

Otherwise there were no big issues...

Saludos

Kare

[guthrie]

Reliability of 996 Engines

Be sure and check the photos of the tear down.

Loren,

Thank you, I looked over the pics and began to read the article. Do you know if there are special tools that are need to split the crank case and deal with pulling the pistons? Additionally, any special tools to put it back together again? Is this a DIY adventure?

Thanks

Hi

I did the rebuilding of a 3.4 engine by myself. I have no previous experience on those things, but had the Porsche workshopmanual. Without it it would have been impossible to do it.

The only "special" tool required was a home made piston circlip installation tool, which I made from two plastic tubes. See attached picture. I cannot remembre the diameters of the tubes, but I think the bigger one was about 3/4", and the inside one was just able to slide inside. I had to sand away a bit for the exterior tube for it to enter the piston installation hole.

I looked the exact position of the circlip, and made a blue line into the "installation tool" to be able to line it correctly to the piston. The small cut you can see in the exterior tube is where the circlip´s hook has to be placed. It was a bit problematic to put the circlip inside, but I found out that even it was not completely perpendicular to the tube, it went into it´s place without problems. Just a light hit to the inner tube, and the circlip went into. Just press the exterior tube tightly against the piston.

I was surprised how easy it was,in the end, after months of investigation how in heaven I´m going to get the circlips in....

When I opened the engine, I removed the cams together with the variocam unit, so here was no need to adjust them. The chains were OK. I also made a small thing to hold the cams inplace when the valve cover was removed.

Otherwise there were no big issues...

Saludos

Kare

Smartrepair...

Thanks for the insight. I see the picture of your tool, the pipe in a pipe however can you explain a little more, how exactly do you use it? Can you define the "circlip"? And finally where does one acquire a "shopmanual"?

[smartrepair]

Reliability of 996 Engines

Be sure and check the photos of the tear down.

Loren,

Thank you, I looked over the pics and began to read the article. Do you know if there are special tools that are need to split the crank case and deal with pulling the pistons? Additionally, any special tools to put it back together again? Is this a DIY adventure?

Thanks

Hi

I did the rebuilding of a 3.4 engine by myself. I have no previous experience on those things, but had the Porsche workshopmanual. Without it it would have been impossible to do it.

The only "special" tool required was a home made piston circlip installation tool, which I made from two plastic tubes. See attached picture. I cannot remembre the diameters of the tubes, but I think the bigger one was about 3/4", and the inside one was just able to slide inside. I had to sand away a bit for the exterior tube for it to enter the piston installation hole.

I looked the exact position of the circlip, and made a blue line into the "installation tool" to be able to line it correctly to the piston. The small cut you can see in the exterior tube is where the circlip´s hook has to be placed. It was a bit problematic to put the circlip inside, but I found out that even it was not completely perpendicular to the tube, it went into it´s place without problems. Just a light hit to the inner tube, and the circlip went into. Just press the exterior tube tightly against the piston.

I was surprised how easy it was,in the end, after months of investigation how in heaven I´m going to get the circlips in....

When I opened the engine, I removed the cams together with the variocam unit, so here was no need to adjust them. The chains were OK. I also made a small thing to hold the cams inplace when the valve cover was removed.

Otherwise there were no big issues...

Saludos

Kare

Smartrepair...

Thanks for the insight. I see the picture of your tool, the pipe in a pipe however can you explain a little more, how exactly do you use it? Can you define the "circlip"? And finally where does one acquire a "shopmanual"?

The circlip is a metallic ring keeping the piston pin (connects connection rod and piston together) on its place . To use the installation tool,first line the connectig rod with the instalation hole,install the piston and insert the piston pin. The circlip is placed inside the outer installation tool tube,with the hook inside the cut.

The tube is then pressed tightly against the piston, lining the installation tools blue line with the piston´s circlip opening. Then a firm hit into the iner tube to install the circlip.

I bought my shopmanual from Ebay, however it was an illegal copy. Porsche sells the legal copies, but with very hefty price. Send me a PM, maybe I could help you.

Kare

[Izzy]

Here is a link to manuals in the UK. Maybe the ones that used to sell in Ebay for $20, now they are just a download - no fee.