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Finally, IMS, is this the answer and ultimate closure.

Do not have your bearing removed if it isn't required!!!!!

If the bearing is in situ in the engine, just remove the outer dust shield. Don't have the bearing pulled out unless it's knackered as this can do more harm than good.

It'll also be a damn sight cheaper to just have the outer dust shield removed too.
 
Yes if your bearing was in good condition when you were inspecting it - then just removing the seal would probably enable it to last as well as anything else on the market - but that will not be for ever nor as long as the larger later bearing will last. The problem is to establish what happened to the bearing up until that point. It could have run OK (as most did) and therefore be a good scenario or it could be worn badly (although you can often see this by testing how lose the cage is and the condition of the grease if any is still in there).

Unfortunately removing and refitting a bearing "in-situ" can damage other internals (even with the use of special tools) - it is unlikely but could happen but it could.

However most of these engines will have a slightly shorter life expectancy that many previous Porsche models. Things like cylinder ovality and cracking, head cracks, scored bores and crankshaft bearings etc will not overall last as long as they did on average in say an SC, a 955/968 etc - and like most older Porsches of all types - will require an engine rebuild one day.

So as the incidence of IMS failures is still relatively low (probably little more than some other failures and much lower than cracked, oval or scored cylinders in later models) and if it looks and seems OK - then removing the seal seems a reasonable risk with the proviso that if it did still fail a larger bearing IMS could be fitted while other things are refreshed or even improved upon (depending on who rebuilds it and the specification chosen).

Current prices show just how much older Porsches are valued and so eventually rebuilds will be an acceptable part of ownership for this model range (as it is becoming for other models) and at least things can be improved while doing so.

Unfortunately claims form others that their "upgrade" will last for ever could only be truly comparatively tested by reproducing what happened to the ones that failed - i.e. fit to several hundred cars and run them for thousands of miles with different owners for several years and then assess the outcome - by which time most will have needed an engine rebuild anyway - and the problem could be resolved during it.

Like a lot of problems with these engines the only way to assess the value of specialists contributions is to read and judge their engineering capabilities and compare the various claims and make a judgement on that - perhaps the volume of engines they work on is a factor as well (as you would soon hear about it if they did a lot and had problems).

It is a mine field however. There are specialists that put a good argument on the Internet to encourage potential customers to trust them that are poor engineers that have been involved in failures that others have had to fix afterwards, lost legal cases and had to pay compensation as a result and tried to persuade people that other specialists had done things wrong by lying about the causes of failures elsewhere - relying on running others down rather than presenting their own credentials and arguments supporting their position.

Such is life and such is the business of attracting customers. You will not however see them prepared or confident enough to try and explain technical issues on the Internet nor debate technicalities as some others have.

Unfortunately - it is the small number of weaknesses in this model range that is the root cause of creating a situation that unscrupulous people can exploit (and is what goes on in business everywhere) and because the background reasons were not avoided by the manufacturer they are far more complicated than most would expect and take a lot of experience and research to correct - so in this scenario - there will always be alternative solutions and technical arguments and some owners will get caught out while others will get it right and there are no easy answers - so good luck whatever you decide to do!

Baz
 
bazhart said:
Yes if your bearing was in good condition when you were inspecting it - then just removing the seal would probably enable it to last as well as anything else on the market - but that will not be for ever nor as long as the larger later bearing will last.

Baz

Okay. Thanks. I think we all put a lot of trust and reverence in what you say. It's just that I'm a bit pedantic and want to get down to some real core absolutes.

Forget all the other stuff that happens to engines. I'm sure I'll want to rebuild my engine someday to upgrade it or just get it to where it can be. And someday I'll be sending my perfectly good engine to Hartech to get an even better one.

But for now, just on the IMS issue, this is the big one. The one that can be sudden and catastrophic. The back of the mind issue.

What I'm hearing you say, is, assuming that the IMS bearing is fine upon examination, remove dust shields. IF it's for some reason not fine, replace with standard Porsche replacement with dust shield removed. That's it? It's seems like a crazily simple solution after al these years of internet mayhem. And that applies to the 3.4 1998 model specifically which is my particularly area of interest?
 
If you inspect the bearing and it's fine, it'll still be in the engine so you will only have access to the outer side of the bearing - this means you will only be able to remove the outer dust shield. The one on the inside of the shaft can not be removed without removing the bearing.

That's perfectly fine though because all the swilling around of the oil is on the outside face of the bearing.


Do not get you mechanic to start pulling the bearing out just to remove the inner face dust shield.

If the bearing is goosed and needs replacing, Porsche don't do them any more so you will need to source one from someone like SKF to the same spec.
Then pull the dust shields off both sides before fitting. Bearing should only cost between £20 - £50.
 
alex yates said:
If you inspect the bearing and it's fine, it'll still be in the engine so you will only have access to the outer side of the bearing - this means you will only be able to remove the outer dust shield. The one on the inside of the shaft can not be removed without removing the bearing.

That's perfectly fine though because all the swilling around of the oil is on the outside face of the bearing.


Do not get you mechanic to start pulling the bearing out just to remove the inner face dust shield.

If the bearing is goosed and needs replacing, Porsche don't do them any more so you will need to source one from someone like SKF to the same spec.
Then pull the dust shields off both sides before fitting. Bearing should only cost between £20 - £50.

I'm sort of speechless. That after millions of posts, hundreds of magazine articles and numerous videos, does it really genuinely all come down to a dust shield? After years of raging ferocious debate, do we all quietly pull a little dust shield of a single component and shuffle quietly away into the normal life, never mention it again?
 
drabux said:
I seem to remember a much cheaper 'direct oil feed' solution which involves drilling a small hole into a nearby oil passage.

Some people have cast doubt on these solutions saying that the oil will spin out under high rpm, unlike the grease that is usually encased within the dust shields.

In the comments below the video there is this comment that relates to your proposal. Which now seems irrelevant anyway because the bearing is perfectly well fed with oil if you remove the dust shield.

"The DOF was designed to fix the problem at the lowest cost (without engine tear down heck, without even removing the engine from the car).
To drill holes in the IMS as you say, you first have to remove the engine, tear it down, remove the IMS drill the holes, clean, reassemble, install.
Do you think that's less than $800?"
 
Niall996 said:
I'm sort of speechless. That after millions of posts, hundreds of magazine articles and numerous videos, does it really genuinely all come down to a dust shield? After years of raging ferocious debate, do we all quietly pull a little dust shield of a single component and shuffle quietly away into the normal life, never mention it again?

As Chris said - All smoke and mirrors

Do you get it now? :grin:

There'll be some snake oil salesmen squirming in their pits reading this post with a cupboard full of 'IMS upgrades' :wink:
 
alex yates said:
Niall996 said:
I'm sort of speechless. That after millions of posts, hundreds of magazine articles and numerous videos, does it really genuinely all come down to a dust shield? After years of raging ferocious debate, do we all quietly pull a little dust shield of a single component and shuffle quietly away into the normal life, never mention it again?

As Chris said - All smoke and mirrors

Do you get it now? :grin:

There'll be some snake oil salesmen squirming in their pits reading this post with a cupboard full of 'IMS upgrades' :wink:

There's also the small point that it was never exactly a common problem anyway....... :grin:

And as Baz said, all you're doing with any of this is reducing probability of component failure, as you can never eliminate it completely.

The only way to reduced it to 8 sigma etc is the fitment of secondary back up systems to cope with component failure. And then you're into Nuclear Reactor / NASA territory.

Warm it up properly, change the oil regularly, make sensible precautionary 'upgrades' as advised. Then like the rest of us spend most of your money on maintenance, petrol and smiles :thumbs:
 
......or buy a Turbo :lol:
 
This is the culprit:
 

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alex yates said:
......or buy a Turbo :lol:

Crazy talk, fool!!! What kind of madman would buy a 996 turbo and use it as a daily driver............? :eek: :eek:ut:
 
alex yates said:
Niall996 said:
I'm sort of speechless. That after millions of posts, hundreds of magazine articles and numerous videos, does it really genuinely all come down to a dust shield? After years of raging ferocious debate, do we all quietly pull a little dust shield of a single component and shuffle quietly away into the normal life, never mention it again?

As Chris said - All smoke and mirrors

Do you get it now? :grin:

There'll be some snake oil salesmen squirming in their pits reading this post with a cupboard full of 'IMS upgrades' :wink:

So would you put all of these in the snake oil salesman 'reject' box.

https://www.youtube.com/watch?v=hzUq2DFpeKw&app=desktop

https://www.youtube.com/watch?v=zKYcfMfL-o0

https://www.youtube.com/watch?v=bS9A8y30eWc

https://www.youtube.com/watch?v=MCqiYU9uU1Y

[/url]https://www.youtube.com/watch?v=kCE-KnTDSvo
 

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