How would you rank 986/987 engine variants for reliability? - Page 3 - Boxster/Cayman - PistonHeads UK

As per the title really, there's a lot of material to read online, but what are your thoughts of strongest to weakness engines in terms of reliability?

Thanks moose, really appreciate that. I'm looking around now, I really do think I need a bit of pork flat six in my life.

Yup, looking around. Have a budget up to about £8k so mainly 986 but there are some 2.7 987 in budget. Weirdly though I really would like a dark blue 986 with ambers... Noticed that the early 2.5's command quite a premium, or maybe just optimistic by the sellers. Between £5-£7k there's pretty much every year and every variant of 986! They're old cars now though so more looking on colours/options I want, condition, history and quality of seller. Oh and working air con. If it just needed a regas you would have done it, so let's safely assume you took it for a regas and it leaked straight out because the condenser and associated plumbing are borked.

The fact that there is a list in the first place will hinder and help people. Telling people that they may need to spend thousands of pounds on a car that may explode at any moment is of course telling all the doubters that any problems that they say never existed was indeed a figment of their imagination. In hindsight just buy any gen2 cars and nothing else, to protect yourself as much as you can. Some people will not have the choice due to finance, so just buy something with a good reputation for reliability for the time being until you can buy something that is proven. If you want to buy a risk, its up to you?? Good luck. Gadgit.

I have owned 3 examples of the 986 S to date and have covered approx 70k miles between them. Never had a problem with any of their engines. All 3 cars were well maintained examples from near the top of the market, but all superb. Would thoroughly recommend purchase of any well looked after 986. Plenty of oil changes always desirable on any high performance car.

The eyes open approach is a pretty essential commodity when looking at them. It seems to me that the best way to buy a 3.4 is with the knowledge available from regulars on here, have a slush fund, and just accept the possible consequences. I couldn't do that and didn't. I'd have liked a Cayman, but just can't cope with the negative possibilities of the 3.4, neither from an enjoyment or financial outlook. That's largely thanks to threads like this, and I was grateful for them when I was looking around. I could have bought a 2.7 and had the relative peace of mind that would offer, but the 3.2 in the Boxster represents the sweet spot for me, and that was the compromise I made. Mine's a mid 2005 car, so there's the IMS question mark, but I regard that as a risk low enough to stomach. If they had made the Cayman with that engine, that's probably what I'd currently own, but I like the Boxster enough to go with it to get the engine I wanted. On the road, it's close enough in performance to the 3.4 not to make any real difference. I'm not knocking the 2.7 at all, the only reason I stopped considering them was that, rightly or wrongly, I felt it may be a harder sell when I wanted out of if it, and my car status is pretty fluid, so having one that's potentially easier to sell matters. I'd agree from the information on offer however, that it represents probably the least risk engine wise, and maybe it'll become the more popular choice as that knowledge becomes more accepted.

Anyone who is classing the single row bearing IMS as being the same risk as the dual is probably not someone with experience in inspecting/replacing hundreds of IMS bearings. The figures from the class action were out of date when offered by Porsche to the court and are now even more dated. Aa everything that rubs against another part wears, so does the IMS bearing and the total figures would be higher by now for both bearings. Does my experience with two cars have any weight? No, not much. Nor does yours. Statistical samples must have lots more data points to be meaningful. I know of cars that have had multiple IMS failures. I know of cars with 300k miles and completely original internals. The luck of manufacturing tolerances and maintenance habits. I've been following this issue since before the first public removal of an IMS bearing and talking to bearing engineers, shop owners, kit providers, etc. So over 8 forums and probably the same number of years, I've read enough anecdotes to know that bearing failure is very real to those whose purse experiences it. And not so much for the lucky ones. But I have read enough to not dismiss it as low risk, even more as low cost impact if it does happen.

Ims failure would worry me more than bore score! When my ims failed on my 2003 986s at 4 years old and 13k bits of bearing made there way around the engine and the failure totalled the engine!Bore score can be more easily monitored before total engine failure! So if I was going m96/7 it would be a post 2006 car! But if funds allowed I would always go gen2!

Chaps, really interesting reading, thanks! So a 2006 2.7 987 is potentially one of the safer choices?

Plate spinner said: Chaps, really interesting reading, thanks! So a 2006 2.7 987 is potentially one of the safer choices? In terms of IMS, I think the safest option is pre 2000, 2.5 models. They have the dual row and they were made in Stuttgart, and shared same factory with 993, same engineers, same technicians. The way they have been put together, super-quality. (Imho). I have looked at many cars 6 years ago when I was purchasing the boxster, unfortunately could not find any low-miles 2.5 but the ones I test drove (2) they somehow felt more solid. I've changed my IMS more than a year ago with my clutch (2000, 986 2.7). It was one of the worse IMS type, and after 60k there was no damage or no wearing. It was clean. We have upgraded anyway but my car is also not built in Stuttgart, its later Finland and I can tell you many parts have been put together in a bit more sloppy way. (Power steering, water pump, exhaust manifold and many more). luckily most have been adjusted during my ownership. According to my indy and several technicians at OPC I talked to, this is mostly about manufacturing tolerances and sloppiness in addition to the driving habits. It's already a s t-design and if some owners really push the car on track-days it might go. (having rear impact also affects I've been told) I've plan to upgrade my IMS again in 4 years, (hoping it won't die until than!

IMS isn't the be all and end all as far as reliability goes. I've got a 986 3.2S that has an intermix problem due to a cracked cylinder head, this is not uncommon, i've seen plenty of cars advertised in this state.

My experience with only two owned is statistically insignificant. But from talking to several folks who have done many hundreds of M96 engine internals and IMS examinations/swaps, the manufacturing tolerances is significant. Other determinants are the load carrying ability of the bearing and the frequency/quality of the oil changes. The 2.5 era first generation double row is good but those are 18 to 20 years old now and wear takes its toll. The 2.7-3.2S second generation single row has both age, wear and design flaws against it. It can be replaced but a good IMS kit isn't cheap and the question arises if you should just play the lottery and take your chances (buy another if yours should fail). After all there are many other things that could take out the engine (wasn't it 28 at last count) or you could crash the car. The third generation single row is far more robust than the prior generations. It can be replaced but the cost is enormous. Every car, every engine, and every manufacturer has weaknesses that show up in quantity production but not in the prototypes. We love our cars and so obsess over them.

Reading the foregoing I'm still not sure about a Gen11 3.4S, which is the car I'd like to buy. Does this have bore or ims issues or is it a safe buy?

Gen 2 987 3.4 is the DFi engine and is relatively fault free bar usual wear and tear, no ims and no bore score issues!

Is it possible for anyone to quantify the very low, low, moderate and high scores that cmoose gave in terms of percentage of models built? For example if high means less than 1% of a particular variant of engine then it's a reasonably low risk regardless, even lower if you take into account the amount of failures caused by lack of maintenance and unsympathetic driving. However if it were to mean 30% then it's a much more tangible risk.

Just to throw my opinion in......I'm with The Watch Bloke and agree with his point. Bad news will always get well reported whereas satisfied owners will say very little. For what it's worth I've owned my 2006 3.4 Cayman S for over 8 years now and still loving every minute of it. No worries and no major issues whilst in my ownership. No faults indicated or reported by the excellent chaps at Redline Racing, Thornaby who look after it service wise. I doubt they put microscopes down the cylinders to check for scoring but then again why should they if the car runs fine? I do not intend to disrespect anyone's extensive knowledge or expertise on the internet but sometimes you can study for years and find fault with everything and never make a purchase! Not every car is good and not every car will break. I owned some rust buckets in the 70's which cost more to keep on the road than my Porsche does! Maybe I'm just lucky at the moment but if I had worried about issues like this way back in 2010 I wouldn't have had my 8 years (and counting) of fun with my Cayman and I'm sure I'm not the only one in this position

I have been on forums for years now however prior to that owned a 986 and 987 blissfully unaware of any ims/bore score issues. I then started reading on here when I bought my 3rd porsche, a beautiful low mileage 987 3.2. It was perfect but I scared myself sh $tless reading ims horror stories so rushed to Porsche and put a warranty on it. Did I get any value out of that warranty? No. Ive owned over 10 Porsches now over the last 12 years some with warranty some without and never had a major problem with any of them, good old internet!!!

I started with a budget of around 10k looking for a 2005 987.1 tip Read all the forums, asked a few questions, including here and decided the 2.7 was the ‘safest’ option - but then thought if i’m Going to buy my first Porsche I want the most powerful I can get and ended up doubling my budget and purchasing a 987.2 3.4 S PDK - was it the right decision? Who knows but I for one would have the issues nagging in the back of my head if I bought a car in the ‘risk’ profile.

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

I agree with moose on this. The risk from ims though is very small anyway and wouldn't put me off buying a perfect example of a 3.2 if I was looking. The bore score risk on a 3.4 gen1 would.

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

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.

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?

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.

anonymous said: [redacted] My LHD 2000 986S was built in Stuttgart. Did Porsche use different bearings depending on the build location?

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.

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

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.

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

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 .

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.

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

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.

Bit bold for anyone to say 'definitive' on this subject. How many 2.5's are known for scoring their bores?

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.

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.

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.

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.

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

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.

This is lifted from BoxaNet: 987 Inter Mediate Shaft Bearing Very early in production the 987 went from a small single row (more problematic but changeable) to large (more reliable but required splitting teh engine to change) IMSB at the engine numbers below This was early in the 2005 model year so nearly all 987s have teh larger bearing:

987.2 2.9 is the sweet spot,9A1 engine has all the bugs worked out,plus the cars have an easier life in general,have had my gen2 for eight years,never misses a beat,bonus is the mass of options ordered by the first/previous owner.

gdaybruce said: This is lifted from BoxaNet: 987 Inter Mediate Shaft Bearing Very early in production the 987 went from a small single row (more problematic but changeable) to large (more reliable but required splitting teh engine to change) IMSB at the engine numbers below This was early in the 2005 model year so nearly all 987s have teh larger bearing: That's the very post I remember.