Definitive Word on IMS
Discussion
Greetings,
Been thinking about getting a Porsche 986 2.7/3.2 for quite a while now. Probably late pre facelift/ early face lift. Aware that IMS is the only real risk with these cars. Read MANY PH posts regarding the subject, going back more than a year now, and all I can say is, I still don't know quite what I should do re IMS if I pull the trigger on one of these cars. I've read, and highly appreciated, more than a few posts and replies from Cmoose (are you a writer?) and Baz of Hartech fame. But it seems, as time's gone by, that there just isn't a clear consensus. First, it seemed fitting an upgraded, larger single row bearing was the way to go. Later, LN Engineering delivered the ceramic bearing, which many swore by - for a time. Then, an American Indy claims it's got nothing to do with the size of the bearing and is actually a lubrication problem. He invents a Direct Oil Feed kit, which squirts oil directly at the bearing, but not all are convinced. You've probably already seen the video, but here it is anyway:
https://www.youtube.com/watch?v=hzUq2DFpeKw
Hartech then kindly respond, saying the following (two thirds down the page):
http://www.pistonheads.com/gassing/topic.asp?h=12&...
I continue researching, and I find a couple of excellent articles detailing DIY clutch and IMS bearing change:
http://boxsterguide.blogspot.co.uk/2010/09/interme...
And:
http://www.mikesspecialtyautomotiveservice.com/ste...
Looks do-able. Tempted to have a go myself if I buy some pork.
However, I think Hartech, if I've understood correctly (many apologies if I haven't; I've certainly been wrong before and I might be wrong this time), advise against changing the IMS bearing in situ, as they say this can cause damage. So now I'm wondering whether upgrading a bearing, in situ, for a bigger single row or ceramic bearing would be wrong.
Then I learn from Baz that taking the seal off the bearing helps considerably, and the chain and sprocket throw up more than enough (cool, filtered) oil to replenish the bearing with oil, at a faster rate than the bearing itself can eject it (and I'm no engineer, but I believe him). But that leaves me asking whether the seal can be taken off the bearing without taking the bearing out of the shaft/engine. Does anyone know?
So, most excellent and learned PHers, I would like to think I have boiled down the whole IMS choice/debacle/guessing games to the following questions. If you care to reply to this post, perhaps you could vote on which one you prefer.
Is it best to:
1. Do nothing and hope for the best (we're talking about a 2001-2003 car here).
2. Replace small single row bearing, in situ, with upgraded larger single row bearing, leaving seal in place.
3. Ditto, but without seal.
4. Replace small single row bearing, in situ, with LN Engineering ceramic bearing, leaving seal in place.
5. Ditto, but without seal.
6. Install aformentioned American Indy's Direct Oil Feed kit (or a similar remote oil feed solution offered by competitor LN), presumably (?) without seal.
7. Simply take seal off existing bearing, if indeed this can be achieved without taking bearing out of shaft.
8. A combination of any of the above!
9. None of the above!
As you can tell, I do not know what the definitive word on the IMS debacle is. But I would like to know. And due to the nature of many Boxsters (and 996s, for that matter) being low mileage second cars, this is an issue which is likely to affect buyers for many years to come; ten plus years at least.
So I think we really need to nail this one once and for all. Thanks for reading this long winded post, and very many thanks for any replies.
Been thinking about getting a Porsche 986 2.7/3.2 for quite a while now. Probably late pre facelift/ early face lift. Aware that IMS is the only real risk with these cars. Read MANY PH posts regarding the subject, going back more than a year now, and all I can say is, I still don't know quite what I should do re IMS if I pull the trigger on one of these cars. I've read, and highly appreciated, more than a few posts and replies from Cmoose (are you a writer?) and Baz of Hartech fame. But it seems, as time's gone by, that there just isn't a clear consensus. First, it seemed fitting an upgraded, larger single row bearing was the way to go. Later, LN Engineering delivered the ceramic bearing, which many swore by - for a time. Then, an American Indy claims it's got nothing to do with the size of the bearing and is actually a lubrication problem. He invents a Direct Oil Feed kit, which squirts oil directly at the bearing, but not all are convinced. You've probably already seen the video, but here it is anyway:
https://www.youtube.com/watch?v=hzUq2DFpeKw
Hartech then kindly respond, saying the following (two thirds down the page):
http://www.pistonheads.com/gassing/topic.asp?h=12&...
I continue researching, and I find a couple of excellent articles detailing DIY clutch and IMS bearing change:
http://boxsterguide.blogspot.co.uk/2010/09/interme...
And:
http://www.mikesspecialtyautomotiveservice.com/ste...
Looks do-able. Tempted to have a go myself if I buy some pork.
However, I think Hartech, if I've understood correctly (many apologies if I haven't; I've certainly been wrong before and I might be wrong this time), advise against changing the IMS bearing in situ, as they say this can cause damage. So now I'm wondering whether upgrading a bearing, in situ, for a bigger single row or ceramic bearing would be wrong.
Then I learn from Baz that taking the seal off the bearing helps considerably, and the chain and sprocket throw up more than enough (cool, filtered) oil to replenish the bearing with oil, at a faster rate than the bearing itself can eject it (and I'm no engineer, but I believe him). But that leaves me asking whether the seal can be taken off the bearing without taking the bearing out of the shaft/engine. Does anyone know?
So, most excellent and learned PHers, I would like to think I have boiled down the whole IMS choice/debacle/guessing games to the following questions. If you care to reply to this post, perhaps you could vote on which one you prefer.
Is it best to:
1. Do nothing and hope for the best (we're talking about a 2001-2003 car here).
2. Replace small single row bearing, in situ, with upgraded larger single row bearing, leaving seal in place.
3. Ditto, but without seal.
4. Replace small single row bearing, in situ, with LN Engineering ceramic bearing, leaving seal in place.
5. Ditto, but without seal.
6. Install aformentioned American Indy's Direct Oil Feed kit (or a similar remote oil feed solution offered by competitor LN), presumably (?) without seal.
7. Simply take seal off existing bearing, if indeed this can be achieved without taking bearing out of shaft.
8. A combination of any of the above!
9. None of the above!
As you can tell, I do not know what the definitive word on the IMS debacle is. But I would like to know. And due to the nature of many Boxsters (and 996s, for that matter) being low mileage second cars, this is an issue which is likely to affect buyers for many years to come; ten plus years at least.
So I think we really need to nail this one once and for all. Thanks for reading this long winded post, and very many thanks for any replies.
Forgot to say, I've seen in the above mentioned DIY articles, and elsewhere, instructions for putting new bearing into freezer overnight before changing, and then tapping it home gently with a rubber mallet. This gives me added confidence that this is a do-able job. Have any of you changed your own IMS bearing, in situ? Did it go in OK without any damage?
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