How would you rank 986/987 engine variants for reliability?

[Bobhon]

So I too am looking at 987 '05 plate 3.2 s's at the moment and this thread isn't putting me off particularly just yet.

The killer question is...... How much does it cost to 'upgrade' the IMS bearing? Also is this something that a reasonable DIY mechanic could undertake?

In my nominal £10K budget a lot of cars have what you might think of as high mileage, say 85K plus. So should I just look for slightly cheaper ones and put the saving to a new IMS bearing?

TIA

[edc]

Yes it's DIY-able by a content home mechanic. Go on the specialist marquee forums and there are owners who will loan out the tools. Otherwise it's quite easy to go on to specialist idy websites and many even price this job on their website.

[Bobhon]

edc said:

Yes it's DIY-able by a content home mechanic. Go on the specialist marquee forums and there are owners who will loan out the tools. Otherwise it's quite easy to go on to specialist idy websites and many even price this job on their website.

Thanks. Never having owned a Porsche can I ask who the good Indies are?

[edc]

I would suggest going on Boxa.net and looking at the map of Indy's. You'll find review of them by then searching the site.

[el romeral]

anonymous said:

[redacted]

My LHD 2000 986S was built in Stuttgart. Did Porsche use different bearings depending on the build location?

[el romeral]

anonymous said:

[redacted]

Ok, just wondered if improved build quality extended to the bearing too! Some great info on this thread so thanks for that.

[Bobhon]

edc said:

I would suggest going on Boxa.net and looking at the map of Indy's. You'll find review of them by then searching the site.

Thanks

[Sly_North]

Hi I bookmarked this page years ago, but I see that posts with the critical information disappeared. Was some account deleted?
I copied some information in my bookmark name, so if it is fine, I feel copying it here could be useful, so here it is:

> Porsche IMS double row: Boxster up to up to 651 12851 - 911 996: double row IMG up to engine 661 14164

If that's incorrect, thanks for correcting.

[bennno]

Lowest risk is early 97-99 which are ok, then 10 plate onwards basically.

[Fiammetta]

The sweet spot is 09 -10/11 . 2.9 with the 9A1 engine .It’s none DFI .The risk how ever small is DFI can clog up the inlet valve stems with crap , which requires a clean out .

Looking at 987.2 s

This is the correct and final answer to your Q .

[bennno]

Fiammetta said:

The sweet spot is 09 -10/11 . 2.9 with the 9A1 engine .It’s none DFI .The risk how ever small is DFI can clog up the inlet valve stems with crap , which requires a clean out .

Looking at 987.2 s

This is the correct and final answer to your Q .

But it's not entirely correct, the early 2.5 engines had a big bearing design that was trouble free.

[Fiammetta]

bennno said:

Fiammetta said:

The sweet spot is 09 -10/11 . 2.9 with the 9A1 engine .It’s none DFI .The risk how ever small is DFI can clog up the inlet valve stems with crap , which requires a clean out .

Looking at 987.2 s

This is the correct and final answer to your Q .

But it's not entirely correct, the early 2.5 engines had a big bearing design that was trouble free.

But open deck cooling Toyota assisted design to minimise parts / costs .This potentially could lead to bore scoring .Not the only reason for BS , but a contributory factor.

9 A1 is closed deck , three not one oil pumps to further assist cooling and more Mezgler influenced .
That’s why it’s the definitive answer .

Why opt into bore scoring risk and IMS ?

Edited by Fiammetta on Tuesday 5th September 18:21

[edc]

Fiammetta said:

bennno said:

Fiammetta said:

The sweet spot is 09 -10/11 . 2.9 with the 9A1 engine .It’s none DFI .The risk how ever small is DFI can clog up the inlet valve stems with crap , which requires a clean out .

Looking at 987.2 s

This is the correct and final answer to your Q .

But it's not entirely correct, the early 2.5 engines had a big bearing design that was trouble free.

But open deck cooling Toyota assisted design to minimise parts / costs .This potentially could lead to bore scoring .Not the only reason for BS , but a contributory factor.

9 A1 is closed deck , three not one oil pumps to further assist cooling and more Mezgler influenced .
That’s why it’s the definitive answer .

Why opt into bore scoring risk and IMS ?

Edited by Fiammetta on Tuesday 5th September 18:21

This all sounds great but what are the actual risks? Where is the data or what are the odds? I don't have any myself but bore scoring on any 986 let alone 2.5 is more or less non existent on the forums.

[Patrick Bateman]

Bit bold for anyone to say 'definitive' on this subject.

How many 2.5's are known for scoring their bores?

[ATM]

bennno said:

Lowest risk is early 97-99 which are ok

I believe this is due to the piston coating used. This was then dropped or changed for something cheaper and result was BS became a thing.

I only know the above in relation to the 3.4 996 engine but no reason to not assume early 2.5 is the same or uses better coating.

[ATM]

Sly_North said:

Was some account deleted?

You will see references above to moose. Not sure what I can say here without my post being deleted. But clearly some content has been removed.

[bennno]

ATM said:

bennno said:

Lowest risk is early 97-99 which are ok

I believe this is due to the piston coating used. This was then dropped or changed for something cheaper and result was BS became a thing.

I only know the above in relation to the 3.4 996 engine but no reason to not assume early 2.5 is the same or uses better coating.

The early 2.5 has a larger and relatively trouble free ims bearing.

[edc]

bennno said:

ATM said:

bennno said:

Lowest risk is early 97-99 which are ok

I believe this is due to the piston coating used. This was then dropped or changed for something cheaper and result was BS became a thing.

I only know the above in relation to the 3.4 996 engine but no reason to not assume early 2.5 is the same or uses better coating.

The early 2.5 has a larger and relatively trouble free ims bearing.

I think you mean dual row rather than larger.

[speedyman]

Good explanation of the issues and fix. I have had my car fitted with the ceramic bearing. https://lnengineering.com/products/the-definitive-...

[Heaveho]

fillpoke2 said:

Does anyone know the date from which the bigger bearing was fitted to 987 3.2S cars?

Quoting an old post, but it hasn't been answered, and new and hopefully accurate info was made available on Boxanet on this subject. It appears from the chassis numbers that mid way through 2005 the 3.2 received the larger bearing. I'm hoping this is correct, as mine is theoretically about 500 into the run of stronger bearing. Mine's a June '05 car, the last 4 numbers in the chassis number denote when the bearing changed.

Annoyingly, I can't find what I thought had been made a sticky with this info on Boxanet now, but it does come up on other forums when searching google.