987.1 3.2S - IMS / Bore score questions

[DaveRB99]

I’ve recently bought a lovely 987.1 Boxster 3.2S and am very pleased with it so far.   Rightly or wrongly, I’ve been trawling through the endless coverage on the internet regarding IMS bearing failure and bore score.

I understand that with the 987.1, from mid 2005, a larger, revised (stronger) IMS bearing was fitted by the factory, but am trying to ascertain how reliable / trustworthy that information is.   I have the M96 engine and I’ve read in a few places that from engine number 62504095, the revised IMS bearing was fitted, bringing with it a very low failure rate compared to the earlier, smaller bearing.    My engine number is 62508103, so is over 4000 engines after the switch (in theory!).   The production date for my car was 22nd June 2005, and again, I’ve read that the switch was made around April 2005.  There’s no record in the car’s history file of any engine work, so I am assuming the IMS bearing is the original one fitted by the factory.

So all good, right?    The thing is, I’ve been told by my local specialist that the only way to tell for sure (because of discrepancies) is to remove the gearbox so that the IMS bearing can be exposed.  I know that with the revised bearing, it can’t be upgraded/replaced without a full strip down, but the earlier smaller (and weaker) bearing can be easily replaced.  I’ve seen this with my own eyes on a 997 engine and now understand why that is the case.

Whilst the car has done 48k miles and would benefit from a new clutch (although it really doesn’t need it yet), it seems silly to pay for the box to be removed, only to find that the IMS bearing is the newer, revised type.    I have read that with the gearbox removed, it’s well worth removing the grease seal off the bearing though, even if it is the revised type, so that lubrication is improved.

Can anyone provide any further reassurance that the switch to the stronger bearing definitely took place from engine number 62504095, outside of the usual comments about it (which I think is just repeated information, probably) on forum threads?

Also, regarding bore score.   Again, I have read that this doesn’t really affect the 3.2 engine, more the later 3.4 as fitted to the 987 Cayman (and Boxster from 2007).   Can anyone comment on this?

I should add that the car drives completely normally, with no strange engine sounds, no oily deposit in the tailpipes (a sign of bore score apparently) so I’m not concerned as such.    Furthermore I have reason to believe my car is in the “sweet spot” for a 987.1 S, i.e. with the revised IMS and no significant bore score concerns, but I’m just looking for further (and ideally definitive) reassurance!

Oh, and here’s a picture of the car - she’s a beauty to my eyes, a classic in the making.    Great spec too with Sport Chrono Plus, PASM, BOSE, Extended leather, Sports seats and steering wheel, Nav, Xenons, Climate, 19” Lobsters, Short shifter etc.   So I’m hoping it will be a lovely, reliable car !

Any thoughts, advice or help would be much appreciated.

[Menoporsche]

Welcome to BoXa and to Porsche Paranoia.  At least one of these is very bad for your mental health.

I don't think anyone here can promise you better than the hundreds of pages of discussion already available, about engine numbers and who has what. No-one here has an insight into Porsche manufacturing that has not been exposed already. If your engine number is in the right range, relax and drive it  

Similarly re bore score. This is not a discussion on 3.2 engines. Relax and drive it  

Your car might throw a shell (has happened) or wear out chain guides and implode that way (has happened). You might lose control of it in the wet and write it off (has happened more than all the above).

It's a great car. Relax and drive it  

[eob]

I've wanted to own a Porsche since I watched Risky Business the first time.

A couple of things have happened in my life that's made me realise that you do not know what is around the corner. A recent event (workmate's adult son was wiped out on his pushbike) made me question, why I was holding back on things?

Enter my 2007 Boxster S nearly 3 weeks ago now.

My 987.1 probably has the bigger bearing, but its a 3.4 S so it might suffer from bore score at some point. But as Menoporsche says, I might put it backwards into a field before that ever happens.

I intend to enjoy this car as much as I can while I can.

I've got in contact with a good local indy so I'll do what I can to mitigate any issues (servicing and such) but I'm going to relax and drive it.

And if you hear any weird noises just tell yourself "they all do that". Thats why I've christened mine "The Angry Penguin"

Edited October 11, 2022 by eob

[½cwt]

The large IMSB went into the 2.7 and 3.2 from early in the 2005 model year and from the numbers probably in very late 2004 (Model year changed in August until more recently 2013 IIRC when it changes in June), engine numbers on the image below which is as definitive as any information out there.  Just be aware that haze a doubt is to teh benefit of those that sell engine repairs or upgrades for IMSB concerns.  Effectively what happened at the factory is that the first 987s were built with engines intended for 986 cars that were not built due to the decline in demand when the 987 was announced.

 

Bore score only affects the larger bore 3.4 (and 3.6 in the 911 models) and is thought to be due to a hotspot developing on the wall of cylinder 6 (IIRC) before the water is fully circulating if the engine is not fully warmed up before being driven hard.  A low temp thermostat is supposed to help mitigate this.

[½cwt]

42 minutes ago, eob said:

...

My 987.1 probably has the bigger bearing, but its a 3.4 S so it might suffer from bore score at some point. But as Menoporsche says, I might put it backwards into a field before that ever happens.

....

Most certainly does have the larger bearing.

[Boxer boy]

I went through all this back in April “hunting “ and eventually went for a 987.2  base with the 2.9  port injection, 9A1 engine .

I have had a few over the decades ( fortunately) 924 , 911 Carrara, 986CS ( new ) , Cayenne 4.6 , Macan SD ( still have that for family hack about ) and last but not least the boxster .

It reminds me in rawness of my 86 911 Carrara which only had 230 Hp without ring twitching handling .In fact the handling is a revelation . 
 

Not helpful for the OP but might be for lurkers wondering what to get .

You can spend hrs reading up on IMS + bore scoring .

My under standing condensing it all is Porsche approached Toyota with a view to assistance in the design of the M96 early engine .Resulting in halving the parts from 400 to 200 and resultant 1/2 production costs or turned around 2 x fast to manufacture using a open deck block for cooling .It’s this open deck that leads to localised hot spots = cylinder liner stripping your bore scoring . 

Mezglers are close blocks use 2 x parts and take 2x long to knock up used on GT 2/3 s and turbos and eventually the 9A1 from 2009 .

Its arguably in some circles  the engine Porsche should have kicked off with back in 96 with the 996/ boxster .

Obviously a lot of M95/96 engines still in circulation .

The answer to the “ extra reassurance “ blunt as it sounds is start your search at 987.2 .

Sorry i can’t sugar coat that advice.

 

 

[Menoporsche]

2 minutes ago, Boxer boy said:

The answer to the “ extra reassurance “ blunt as it sounds is start your search at 987.2 .

At which point you worry about an oil leak in your PDK requiring a replacement gearbox...

The answer is to stop worrying.

[½cwt]

2 minutes ago, Boxer boy said:

I went through all this back in April “hunting “ and eventually went for a 987.2  base with the 2.9  port injection, 9A1 engine .

I have had a few over the decades ( fortunately) 924 , 911 Carrara, 986CS ( new ) , Cayenne 4.6 , Macan SD ( still have that for family hack about ) and last but not least the boxster .

It reminds me in rawness of my 86 911 Carrara which only had 230 Hp without ring twitching handling .In fact the handling is a revelation . 
 

Not helpful for the OP but might be for lurkers wondering what to get .

You can spend hrs reading up on IMS + bore scoring .

My under standing condensing it all is Porsche approached Toyota with a view to assistance in the design of the M96 early engine .Resulting in halving the parts from 400 to 200 and resultant 1/2 production costs or turned around 2 x fast to manufacture using a open deck block for cooling .It’s this open deck that leads to localised hot spots = cylinder liner stripping your bore scoring . 

Mezglers are close blocks use 2 x parts and take 2x long to knock up used on GT 2/3 s and turbos and eventually the 9A1 from 2009 .

Its arguably in some circles  the engine Porsche should have kicked off with back in 96 with the 996/ boxster .

Obviously a lot of M95/96 engines still in circulation .

The answer to the “ extra reassurance “ blunt as it sounds is start your search at 987.2 .

Sorry i can’t sugar coat that advice.

 

 

I understand and appreciate this additional insight, I was unaware until now of the Toyota involvement in the development, but budget does not always permit buyers to follow this guidance. 

There is a fair base of well researched information out there that I have been gathering into one place, so I have the confirmed engine numbers for the 986 and 996 at which the dual row became single row IMSB (they are actually given int eh Porsche parts catalogues) and then when it was enlarged, I have the 987 engine numbers. 

Bore score is exceptionally rare in any Boxster engine that is not a 3.4 to the extent of being a negligible risk compared to other things that could give you a hefty bill.

Sugar coating may not be possible but having an informed position to understand the risks and the likelihood of their occurrence before buying is possible.

[Boxer boy]

1 minute ago, Menoporsche said:

At which point you worry about an oil leak in your PDK requiring a replacement gearbox...

The answer is to stop worrying.

Manual for more involvement as it’s a high day and Sunday car essentially.

My Macca has 2 1/2 yrs of Porsche warranty to run so so any issue inc PDK s are not keeping me awake .

Heard as well a few Indy’s are starting to open up PDK boxes and “have a go “.For those unaware Porsche do them a a sealed units and throw away parts …the whole thing .Techs aren’t guided to / open / replace parts and thus repair them .

 

One does wonder theses days running two Porsches , if it’s like juggling hand grenades and one day a pins gonna fall out with one between hands ! 
You can only do ….so much it’s easy via Mr Google to overthink it all .

Conclusion = stop worrying.Agree .

[iborguk]

Enjoy the car , check the roof drains, regularly.

[Lonewolfgjp]

I had a very similar car, mine had the earlier IMS and the previous owner had fitted the ceramic bearing. My car had about 94k on it when I sold and the only time it let me down was the gear cable snapping. 

It’s easy to get wrapped up in all the internet information but in truth these cars are generally reliable.

They are great cars , just get on and enjoy it !
 

 

[DaveRB99]

Thanks for all the replies so far.   Seems that the best we can do in terms of engine numbers etc is just reply on the info on the web - so I think I can assume that mine has the larger (and stronger) bearing.  I fully intend to enjoy it and not worry, I was just wanting to understand what, if any, risks I am dealing with.

Bore score wise, that’s pretty much what I’ve already heard, i.e. that it’s pretty rare on a 3.2.

Regarding the roof drains, where are they?    I’ve seen a couple of holes when the roof is half way up, presume it’s those?

I’ve already replaced the ball joint ends on the pushrods, and the roof elastic on one side to ensure it tucks into the window frame properly, is there anything else I need to do roof wise, does it need any lubrication periodically?

[Paul P]

1 hour ago, DBarthorpe said:

Thanks for all the replies so far.   Seems that the best we can do in terms of engine numbers etc is just reply on the info on the web - so I think I can assume that mine has the larger (and stronger) bearing.  I fully intend to enjoy it and not worry, I was just wanting to understand what, if any, risks I am dealing with.

Bore score wise, that’s pretty much what I’ve already heard, i.e. that it’s pretty rare on a 3.2.

Regarding the roof drains, where are they?    I’ve seen a couple of holes when the roof is half way up, presume it’s those?

I’ve already replaced the ball joint ends on the pushrods, and the roof elastic on one side to ensure it tucks into the window frame properly, is there anything else I need to do roof wise, does it need any lubrication periodically?

987 drain locations 

 

A ptfe based spray lube is good for roof mechanism. Anything that pivots or slides. There's a few available wd40 do one as do Wurth

Edited October 11, 2022 by Paul P

[Lewis987]

On 10/11/2022 at 12:05 PM, DBarthorpe said:

   Great spec too with Sport Chrono Plus, PASM, BOSE, Extended leather, Sports seats and steering wheel, Nav, Xenons, Climate, 19” Lobsters, Short shifter etc.   So I’m hoping it will be a lovely, reliable car !

 

 

Blimey that is a good spec!! I was pleased to get heated seats and a PSE on mine!

Have you got a picture of the sports steering wheel please? I'm considering replacing mine, but have stone grey leather which is going to be cause for a retrim as any for sale are black leather... 

[Menoporsche]

Sports SW on the 987.1 has a round airbag/centre rather than a triangle, IIRC.

I believe it's different for the 987.2 - I got the impression they all have round centres.  Might be wrong.

[944GS]

3 hours ago, Lewis987 said:

Blimey that is a good spec!! I was pleased to get heated seats and a PSE on mine!

Have you got a picture of the sports steering wheel please? I'm considering replacing mine, but have stone grey leather which is going to be cause for a retrim as any for sale are black leather... 

Here’s my sports steering wheel, recent re trim done by Royal Steering Wheels for £185.

 

[bally4563]

4 hours ago, 944GS said:

Here’s my sports steering wheel, recent re trim done by Royal Steering Wheels for £185.

 

Nice job they have done, how much did that hurt the pocket?

[bally4563]

Just now, bally4563 said:

Nice job they have done, how much did that hurt the pocket?

Sorry just read the thread properly 😂 all in or plus the dreaded ? 20%

[944GS]

1 hour ago, bally4563 said:

Sorry just read the thread properly 😂 all in or plus the dreaded ? 20%

That included the VAT so just the £9.99 postage to add to it.

[Lonewolfgjp]

Looks great! 
 

Its a nice style wheel and with the fresh retrim looks very sharp 👍

Did you have the shifter and the hand brake done to match?

[944GS]

1 hour ago, Lonewolfgjp said:

Looks great! 
 

Its a nice style wheel and with the fresh retrim looks very sharp 👍

Did you have the shifter and the hand brake done to match?

Just the steering wheel for now.

[dim33]

I had an interesting discussion with indy ePorsch in the summer when having my car serviced regarding the IMS bearing.

I also have the bigger bearing in my 3.4S and my understanding was that this cannot be changed without engine disassembly. However I was informed by ePorsch that they can change the larger bearing without disassembly. They machine the casing so that the opening is large enough to replace the larger bearing and then fit a larger bearing cover. They also make sure that the inside of the engine itself is under pressure so that the flecks created by the machining process are blown outward.

This is good to know. However, I don't recall reading anywhere about catastrophic failure of the larger bearing. So any fear regarding this larger bearing failing is not proportional to the actual risk.

Furthermore, they explained that when the IMS bearing starts to properly fail, you can clearly hear an alarming rattling sound and any enthusiast owner will get this looked into before catastrophic failure. 

I too went through Porsche paranoia when I bought mine in 2018, so I get where the OP is coming from. 

[Menoporsche]

13 minutes ago, dim33 said:

Furthermore, they explained that when the IMS bearing starts to properly fail, you can clearly hear an alarming rattling sound and any enthusiast owner will get this looked into before catastrophic failure. 

That's sincerely news to me, especially from Eporsch. You can clearly hear it, for about 3 seconds before the engine implodes AIUI.

I think these IMS concerns were valid when the cars were worth 20k plus and they were happening frequently, to 986 that were less than 5 years old. By now the solution is getting out of proportion to the car's value, IMHO, and there's a line of thinking that says they were due to initial build intolerances so "if bad it would have gone by now".

Anyway, each to their own.

[Jonttt]

Well this is a sensible reasaoned thread....there is indeed a Porsche for everyone 

To the OP congrats on the car, that is indeed a great spec boxster you have, enjoy !

[DaveRB99]

On 10/24/2022 at 12:19 PM, Jonttt said:

Well this is a sensible reasaoned thread....there is indeed a Porsche for everyone 

To the OP congrats on the car, that is indeed a great spec boxster you have, enjoy !

Cheers!   I’ve driven it loads in the last few days, I can’t believe how good they are for such little money.   I know we all have to keep on top of some stuff, maintenance wise, and things like air con condensers, coolant crossover pipes, etc come to mind, but honestly, as someone who has had 11 Lotuses in the last 3 decades, I’m massively impressed with the way this thing drives.   Long may that continue….

I’m pretty sure I’m not going to bother getting the box dropped to check which IMS bearing I have.   Everything I’ve seen/read indicates it isn’t the weaker one…