Metal bits..

[911 dreamer]

Thanks guys, I will aim to drop the pan myself and report back with pictures.

Enjoy your weekends :)

[Ahsai]

Hi John, just wondering if you have any opinion or excpeience with this sealed bearing? http://www.fvd.de/us/en/Porsche-0/-/-/-/item/item_details/VID_45438-VCD_59644405-gid_281-sort_4-display_50-item_FVD10590104/Spare_Parts_-_Clutch_-_Cluch_Kit_FVD10590104_Intermediate_Shaft_IMS_Repair_Kit_`M96.Dual_Row`.html

If the engine has significant debris, would fitting a sealed bearing a better choice and maybe switch to an open bearing at the next clutch change after no more debris are found?

 

That bearing is a cheaper alternative type bearing, not unlike what Pelican offered as a cheap substitute for the LN hybrid ceramic bearings.  In essence, it is nothing more that a new OEM type bearing.

 

Getting the debris and its source out of the engine is key to any path forward.  The problem with the grit is not just the IMS bearing, it is every bearing surface in the engine.  Full flow filtration, quality oil, shorten oil change cycles, and magnetism would be the best approach short of tearing the engine down.

Thanks John. While this bearing is not a ceramic bearing, it does have dual rows unlike the Pelican single row + a spacer.

Once there are debris, I think even with the best filtration, the lingering debris can still be picked up by the chains or sucked into the scavenge pumps, etc. so I thought fitting an open bearing sounds quite risky.

[JFP in PA]

 

 

Hi John, just wondering if you have any opinion or excpeience with this sealed bearing? http://www.fvd.de/us/en/Porsche-0/-/-/-/item/item_details/VID_45438-VCD_59644405-gid_281-sort_4-display_50-item_FVD10590104/Spare_Parts_-_Clutch_-_Cluch_Kit_FVD10590104_Intermediate_Shaft_IMS_Repair_Kit_`M96.Dual_Row`.html

If the engine has significant debris, would fitting a sealed bearing a better choice and maybe switch to an open bearing at the next clutch change after no more debris are found?

 

That bearing is a cheaper alternative type bearing, not unlike what Pelican offered as a cheap substitute for the LN hybrid ceramic bearings.  In essence, it is nothing more that a new OEM type bearing.

 

Getting the debris and its source out of the engine is key to any path forward.  The problem with the grit is not just the IMS bearing, it is every bearing surface in the engine.  Full flow filtration, quality oil, shorten oil change cycles, and magnetism would be the best approach short of tearing the engine down.

Thanks John. While this bearing is not a ceramic bearing, it does have dual rows unlike the Pelican single row + a spacer.

Once there are debris, I think even with the best filtration, the lingering debris can still be picked up by the chains or sucked into the scavenge pumps, etc. so I thought fitting an open bearing sounds quite risky.

 

 

It is a dual row steel bearing with seals on it, just like the OEM unit.

 

The debris is definitely a threat to an IMS bearing without seals, which is why both Jake and LN have said for years that if the sump has appreciable grit in it, the engine is not a candidate for the retrofit.  The principal reason they did this was to limit the number of LN IMS retrofit failures which were not caused by the bearing but by other factors which often conveniently get left out of internet postings.  On the same subject, but closer to home, we have been asked more than once to do a retrofit on engines with obvious considerable ferrous grit issues in the sump that looked like the early to mid stages of an IMS failure.  While we have always declined to retrofit questionable engines, a couple of the owners choose to go elsewhere or do the retrofits themselves using unsealed IMS bearings, which unfortunately did not work out (engine's failed in as little as 60 miles post retrofit), but these failures were not the IMS bearings, they were rod and main related, or due to the oil pump being chewed to Hell by the debris.  So more than just the IMS is at risk in these situations.  I have only ever head about a very small number of engines with obvious IMS problems that have lived any period of time after a retrofit and many, many oil and filter changes in a very short period of time, and no one really know how much longer they lived beyond the owner's last forum posting.

 

When there is small amounts of ferrous debris in the sump, we will remove the IMS and inspect it; it the balls and race look like the surface of the moon, we stop there and recommend pulling the engine for further inspection.  But more often than not, engine's with just a small amount of debris in the sump have been found to have near perfect IMS bearings, confirming that not all of the debris comes from the IMS.

[911 dreamer]

Hi John & Ahsai, I dropped the pan today and took lots of photos of it, the mag drain plug and the inside of the filter housing (mags on the outside). Not sure what this means for the engine..?

 

The parts from the centre of the pan were what looked like part of a rubber seal (black bits) and dark brown plastic. The metal, centre and sides was mainly ferrous. Some of the photos are pretty close up so the debris may look a bit bigger than it actually is.

 

Not sure what else to tell you both but please ask if I've missed out any info or pictures you'd like to see.

 

Thank you.

[911 dreamer]

[911 dreamer]

I did name the images but the names haven't shown on here. If you're not sure what anything is please ask me.

[911 dreamer]

I did name the images but the names haven't shown on here. If you're not sure what anything is please ask me.

BTW - this has done about 300 miles, if that, since the last oil change but the pan didn't come off at this point, as far as I know it's the first time it's been off. I haven't re-filled the oil or put a new filter in yet, planning to get your opinions and have it trailed to a specialist if necessary.

[JFP in PA]

Run a magnet over the crap in the sump cover and see how much gets picked up.  I'm not overly concerned about the plastic bits.

[911 dreamer]

Thanks for the quick reply John, as I've done this on my driveway it's now dark so I'll have to check tomorrow after work. I should have checked them earlier but didn't think.

The metal in that circular dimple bit in the centre of the pan was mainly magnetic, apart from the plastic and rubber. I'm guessing that rubber is part of the seal from the original ims?

Initial thoughts if the deposits each side are mainly magnetic, non-magnetic?

[JFP in PA]

Thanks for the quick reply John, as I've done this on my driveway it's now dark so I'll have to check tomorrow after work. I should have checked them earlier but didn't think.

The metal in that circular dimple bit in the centre of the pan was mainly magnetic, apart from the plastic and rubber. I'm guessing that rubber is part of the seal from the original ims?

Initial thoughts if the deposits each side are mainly magnetic, non-magnetic?

 

You are close to the edge on a go/no go retrofit with that amount of debris, particularly with that amount of ferrous material.  The synthetic material can come from multiple sources, including the wear pads on the chain tensioning paddles.

 

If your car was in my shop, this would be one of the cases where I would pull the IMS and open it up to see what is looks like before proceeding.

[911 dreamer]

Ok many thanks I'll let you know about those other bits as soon as possible.

[Ahsai]

Agreed with John and I'm also concerned about the ferrous debris on the drain plug in such a short mileage, which means something is actively shedding steel.

[911 dreamer]

Hi both, please see pictures of the debris from the pan, as said before I don't know when this came off last if at all, so this is not necessarily from low miles. I used the mag plug to pick up what was in the pan...

[911 dreamer]

Sorry I forgot to ask, what type of sealant / loctite should be used when re-installing the pan?

 

Thank you.

[JFP in PA]

Sorry I forgot to ask, what type of sealant / loctite should be used when re-installing the pan?

 

Thank you.

 

Loctite 518 is the preferred sealant.

[911 dreamer]

Many thanks.

[911 dreamer]

John, Ahsai,

 

Update time!

 

I've had the engine stripped down, went to see it the other night and according to the guy who's doing it it's all in pretty good condition, liners, cams etc. He's going to replace the crankshaft bearings while it's apart, but the offending item was......you guessed it!

 

How lucky was I that it didn't go bang?!

 

He wants to replace the whole shaft as opposed to just the bearing and I believe that means getting one from the US so I reckon it'll be the end of November before I get it back. I feel lucky to have caught it in time, and lucky to have found someone experienced to do the job, looking forward to getting back my almost spotless 996 with a new lease of life :)

 

 

[Ahsai]

You should go buy a lottery ticket :)

Replacing the whole shaft isthe proper fix since its also damaged by the disintegrating bearing.