IMS question. - 986 Forum - The Community for Porsche Boxster & Cayman Owners

mikes_box · 02-26-2009, 12:20 AM

Can the ims be upgraded on the boxsters as a precaution... looking at on 00 at 39k miles and don't want to have it go out as soon as i buy it...

jmatta · 02-26-2009, 05:31 AM

Contact Jake Raby, board sponsor at www.flat6innovations.com or click on the big logo, upper right hand corner.

SeanZ4 · 02-26-2009, 05:59 AM

Mike, I have a '00 S with 38k. I went through all the same anxiety that you're going through. I'm a long time bmw driver and always stayed away from the boxsters for the very same thing you're worried about. Do a search of my screen name and you'll find some very good posts from other members back in January to me about my worrying about ims failures. Hopefully it will put your mind at ease.

sean :-)

Jake Raby · 03-15-2009, 03:31 PM

One of the fixes we had planned for the IMS originally was to make the roller bearing end of the shaft also supported by a plain bearing thats hydrostatically lubricated and we may still try this.. But our current fixes are working great and the key is now to reduce the loads the IMS sees...

Look for much more information being shared soon, including more videos that describe the engine internals.

mikefocke · 02-26-2009, 06:10 AM

Can it be done, yes.

Is it cost effective, no. You currently have to split the case apart to get at the IMS bearings though someone is reputed to be working on a version that allows a replacement with merely the motor removed from the chassis and no need to go inside the crankcase.

Just like any other car...some fail. And just like any other car...drive it, enjoy it, break it and fix it in that order if it happens.

My Boxster S '01 has had lots less problems than my '01 Acura TL and none serious in trouble or $. My prior '99 Boxster had no problems. My prior 914 couldn't stay out of the shop.

Lil bastard · 02-26-2009, 07:29 AM

Start funding your own multi-$B 'Bailout Plan' just in case, and then forget about it.

If it goes KaBoom, you have a headstart and if not, you have a nice little egg waiting for you.

cnavarro · 02-26-2009, 01:22 PM

http://www.lnengineering.com/ims.html

I have a very detailed explaination of all the differences between the various IMS's from 97-08, and what can be done.

You have a few options:

If it's a single row bearing IMS, yes, you can remove the bearing and replace it with our IMS retrofit kit (available from Flat 6 Innovations).

If it's a dual row bearing IMS, as posted earlier, you can only update it by tearing the engine down and sending us your IMS, which we then modify, and returned upgraded.

There isn't a good way to identify what kind of IMS you have, single row or double row, short of pulling the flywheel and doing a physical identification. At this point, what can be done regardless of model year is that you can remove the seal off the front of the IMS "sealed" bearing, to allow better lubrication of the bearing. I have an explaination of why on the page I linked to above. It's best to do this when doing a clutch job, since you have to pull the transmission as well as the flywheel to get access to the IMS.

Fire away if anyone has any questions after reading all the details on our web page.

The only other recommendations I have are that you should change your oil often AND you should use an oil like Royal Purple, or something that has a quality friction modifier, like moly. This will help improving longevity of the IMS bearing once the seal is removed from the front to allow fresh oil to cool and lubricate the bearing.

schoir · 02-26-2009, 03:58 PM

Quote:

Originally Posted by cnavarro

http://www.lnengineering.com/ims.html

I have a very detailed explaination of all the differences between the various IMS's from 97-08, and what can be done.

You have a few options:

If it's a single row bearing IMS, yes, you can remove the bearing and replace it with our IMS retrofit kit (available from Flat 6 Innovations).

If it's a dual row bearing IMS, as posted earlier, you can only update it by tearing the engine down and sending us your IMS, which we then modify, and returned upgraded.

There isn't a good way to identify what kind of IMS you have, single row or double row, short of pulling the flywheel and doing a physical identification. At this point, what can be done regardless of model year is that you can remove the seal off the front of the IMS "sealed" bearing, to allow better lubrication of the bearing. I have an explaination of why on the page I linked to above. It's best to do this when doing a clutch job, since you have to pull the transmission as well as the flywheel to get access to the IMS.

Fire away if anyone has any questions after reading all the details on our web page.

The only other recommendations I have are that you should change your oil often AND you should use an oil like Royal Purple, or something that has a quality friction modifier, like moly. This will help improving longevity of the IMS bearing once the seal is removed from the front to allow fresh oil to cool and lubricate the bearing.

Charles:

Thank you for the excellent information. That article is so informative and so well presented that it borders on being a scholarly dissertation.

It is so refreshing to find first hand information on the internet.

Regards, Maurice.

cnavarro · 02-28-2009, 03:56 PM

No problem, glad you found it informative.

We just got an IMS in that was literally minutes away from failure - the 2.5 engine it came out of actually suffered a rod bolt failure before the IMS and that's why it came apart.

I'll get some video of the IMS bearing out of this one so everyone can see one right prior to failing - it's amazing!

ppbon · 03-13-2009, 02:00 PM

Quote:

Originally Posted by mikefocke

My prior 914 couldn't stay out of the shop.

That's because it wasn't my shop

Happy Boxstering,
Pedro

jmatta · 03-14-2009, 06:55 AM

Thanks again, Charles. As I've said before, you take alot of the mystery out of these engines with your explanations, and now the videos.

Brucelee · 03-14-2009, 08:30 AM

The video is worth a million words, especially because it is so well done that it takes a lot of the mystery out of this particular weak point in the M96 engines. It is an excellent supplement to the article on your website.

C'mon. Porsche will not admit that there is any "weak points" in these engines. That is just a vicious rumor spread by BMW, right?

Blue-S · 03-14-2009, 09:13 AM

This may be a dumb question, but here goes: Surely, they don't support the whole IMS with a bearing at just one end. There is a bearing at the other end of the IMS, right? What does that bearing look like? Why doesn't it fail?

Jake Raby · 03-14-2009, 06:47 PM

There is no other bearing opposite the failure prone IMS bearing.

There is no bearing insert in the case, the bearing just rides against a machined portion of the case and is lubricated hydrostatically... The cams ride in the heads without bearing inserts as well.. Much like a 36HP VW engine or a 356 engine- No cam bearing inserts.

Brucelee · 03-15-2009, 07:06 AM

BTW-this technical discussion is great.

Thanks to all who are contributing.

Has anyone posted a schematic of the engine yet?

j.fro · 03-15-2009, 07:31 AM

I just finished watching Charles' video...thanks so much for posting that. It was one of the scariest movies I've seen in a long time! Those bearings remind me of the bearings in coaster-brake bicycle hubs. ugh

litteng · 03-15-2009, 04:20 PM

Those blasted bearing cages... one of the biggest headaches with the bmw single sided swingarm R1100/1150 motorcycles has been cage failures and then the differential large bearing piles up,

this should be something that wants to be checked anytime you have the gearbox off for clutch service etc.

thanks for being so kind to show us whats going on,

Charles & Jake; the metal flaking from the bearing ball and races, does any of it show up in UOAnalysis, i would suspect that at the least we sould be able to find it in the filter ?

Blue-S · 03-15-2009, 10:24 AM

Quote:

Originally Posted by Jake Raby

There is no other bearing opposite the failure prone IMS bearing.

There is no bearing insert in the case, the bearing just rides against a machined portion of the case and is lubricated hydrostatically... The cams ride in the heads without bearing inserts as well.. Much like a 36HP VW engine or a 356 engine- No cam bearing inserts.

Well, that's a surprise! Now I am left wondering why Porsche designed the engine with a pressure lubricated bearing surface at one end of the IMS, but a sealed bearing at the other end. I know that the use of the aluminum case and head surface as bearing area is very common -- most overhead cam cylinder heads are built this way -- but the use of a sealed bearing inside an engine is highly unusual. I have seen sealed bearings used successfully inside transmissions, but in that application the bearing does not have to cope with fuel and water laden engine oil attacking the seals.