991 Gt3 Engines
Discussion
Just go into it with your eyes open. I'm biased, having just bought a 991.1 GT3, but I did my homework, including canvasing opinions here, and poring over the details on the Rennlist threads from the concerned owners group. I bought a car on a late G series engine, fitted in 2017, and plan to just carry on extending the warranty as long as I own it. I'll do the odd track day here and there, but I won't be doing 10+ days a year, but nor will I spend my life pootling around under 4k rpm - my old Turbo did that very well!
I do expect the value will take a bit of a hit if I still own it when the engine warranty nears expiry, but even so, that hit won't be as big as many other cars I could have spent £100k on. In the meantime, I'll have been driving a GT3 :-)
I do expect the value will take a bit of a hit if I still own it when the engine warranty nears expiry, but even so, that hit won't be as big as many other cars I could have spent £100k on. In the meantime, I'll have been driving a GT3 :-)
Macca993 said:
The key is to go in eyes wide open, the 991.1 GT3/RS engine issues are not a 5% or 10% thing - they will affect ALL cars at some point if driven to redline (and afterall the big boast and difference for the 991 GT3 was indeed the 9000 rpm limit which is most usefull on the track where the car was designed to be used to its design brief).
Not disagreeing with you Macca but this was Porsches explanation of the issue taken from the COG meeting thread on Rennlist. Have Porsche got it wrong then?Edited by Macca993 on Wednesday 6th February 01:41
Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Flat0ut said:
Not disagreeing with you Macca but this was Porsches explanation of the issue taken from the COG meeting thread on Rennlist. Have Porsche got it wrong then?
Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Inclusion or porosity then. Cheap forgings or castings basically. Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Slippydiff said:
Flat0ut said:
Not disagreeing with you Macca but this was Porsches explanation of the issue taken from the COG meeting thread on Rennlist. Have Porsche got it wrong then?
Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Inclusion or porosity then. Cheap forgings or castings basically. Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Olivera said:
Slippydiff said:
Flat0ut said:
Not disagreeing with you Macca but this was Porsches explanation of the issue taken from the COG meeting thread on Rennlist. Have Porsche got it wrong then?
Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
Inclusion or porosity then. Cheap forgings or castings basically. Porsche's Second Presentation: Understanding The Issue
Dr. Walliser ran this presentation. He explained the cause of the finger follower wear issue, and the steps Porsche has taken to resolve it. Without getting into a great amount of detail, which we are unqualified to do, the issue is caused by a metallurgy defect (inclusion) close to the surface of the finger follower. Most finger followers do not have these inclusions, or they are not close enough to the surface to cause increased finger follower wear. This explains why the vast majority of 991.1 GT3's do not, and most likely will never experience this problem.
Individual driving patterns, engine variations (temperature, oil quality, oil viscosity, parts tolerances, etc.) are secondary factors. The combination of one or more of these factors, along with inclusions, can cause excessive finger follower wear, indicated by engine misfires resulting in a check engine light (CEL).
inclusion in British
(?n?klu???n )
noun
1. The act of including or the state of being included.
2. Something included.
3. Geology : A solid fragment, liquid globule, or pocket of gas enclosed in a mineral or rock.
4. Strict inclusion.
5. Engineering : A foreign particle in a metal, such as a particle of metal oxide.
And from the Rennlist thread he quoted verbatim from :
"Dr. Walliser explained that Porsche had to develop new engine tests to recreate these patterns. With new baseline testing in place, Porsche was able to reproduce and diagnose the issue, and develop new finger followers and camshafts using revised manufacturing processes and specifications. Dr. Walliser presented test results and images that demonstrate the effectiveness of the new parts. After more than double the test hours of engines that failed, the new finger followers looked as though they were new in comparative photos. In fact, we initially thought they were new. We saw no visible wear."
That (to me anyhow) seems pretty conclusive that the early issues stemmed from cam follower failures ... what caused failures subsequently I'm in no place to comment on, but when Dr Walliser is that candid about the follower and cam issues, along with my knowledge of casting/forging processes AND the VAG group's need/desire to minimise manufacturing costs and maximise profits, you can rest assured the castings or forgings weren't good quality, purely because good quality casting and forgings (especially those used for something as critical as cam followers) don't contain inclusions and need to be made from the correct materials.
The inclusion of inclusions (excuse the pun) and the question mark over the material used would tend to indicate cost cutting and poor quality components either by design and/or as a result of poor casing/forging processes/procedures.
That Porsche saw fit to "develop new followers AND camshafts using revised manufacturing processes AND specifications" would only seem to add further weight to that argument.
Edited by Slippydiff on Wednesday 6th February 19:28
Firstly excuse my ignorance in not being as mechanically minded as others on here , but if it's only the finger followers at fault then why replace whole engine?
Read an article why Kawasaki used finger followers in the 80s then returned back to shim and bucket for sports bikes, basically not easy or cheap to manufacture or as reliable as shim and bucket https://www.bennetts.co.uk/bikesocial/news-and-vie...
Read an article why Kawasaki used finger followers in the 80s then returned back to shim and bucket for sports bikes, basically not easy or cheap to manufacture or as reliable as shim and bucket https://www.bennetts.co.uk/bikesocial/news-and-vie...
Edited by GT4P on Wednesday 6th February 18:14
Macca993 said:
As co-founder of the "GT3 World Wide Action Group" (google it) back in 2014 on this issue with Sunil lets be clear here.
The 10 year warranty is a band aid. The engine was re-designed with solid lifters in the 991.2
I think I understand all in this fab and very informative post.... doffs hat.The 10 year warranty is a band aid. The engine was re-designed with solid lifters in the 991.2
Edited by Macca993 on Tuesday 5th February 21:41
But, for the simple minded isn’t the answer here in plain sight, why not find a 991.1 GT3 yet to have this issue or one where the engine might just have been replaced say because it went into limp mode when driven ads described;-) and fit the solid lifters?
All wise word taken on board.
Thanks
Ed
GT4P said:
Firstly excuse my ignorance in not being as mechanically minded as others on here , but if it's only the finger followers at fault then why replace whole engine?
Read an article why Kawasaki used finger followers in the 80s then returned back to shim and bucket for sports bikes, basically not easy or cheap to manufacture or as reliable as shim and bucket https://www.bennetts.co.uk/bikesocial/news-and-vie...
Simply because if the followers and cams have worn, they'll have deposited what are effectively "iron filings" into the lubricating system of the engine, these will have then been pumped around the engine to lots of other critical bearings and bearing surfaces, not to mention critical components such as oil/scavenge pumps and hydraulic tappets. Read an article why Kawasaki used finger followers in the 80s then returned back to shim and bucket for sports bikes, basically not easy or cheap to manufacture or as reliable as shim and bucket https://www.bennetts.co.uk/bikesocial/news-and-vie...
At that point it becomes cheaper and more cost effective to pull the complete engine and replace it with a factory built item, rather than pay an OPC to strip and clean the scrap engine and re-build it using new parts.
And on the basis most OPC's are more adept at changing Boxster brake pads/discs and wiper blades than rebuilding high revving engines in the required conditions (ie total cleanliness) it's probably just as well Porsche decided on the course of action they did.
Dr Wallisers explanation is not entirely sound.
His explanation although correct in the fact that the chosen materials were not up to the task at hand given the situation being imposed by the hydraulic lifters having difficulty to respond with uniformity above 8700 rpm, were misleading by not explaining the route cause - with correct and consistent pressure between the finger follower "pad" and the tip of the camshaft lobe at high rpm - there is actually no need for the metallurgy to be as critical as he has stated.
They tried to use light weight finger followers using MIM (metal injection moulding) and then creating a hard surface without weight sacrifices using DLC (diamond like coating) to give the surface low friction and strength. The theory was sound, however the issues could not control were the adequate oiling of the valvetrain across all cyclinders under sustained high rpm to create consistent pad and lobe contact forces. This is no way a new challenge for automotive manufactuers designing a road car engine that spins beyond 9000 rpm, look at high rpm motor cycle engines as reference. It can be achieved for a 9000 rpm engine but they had already take the worng design path by the time the engine was in production!
Porsche would never admit to a public group they had a fundamental design issue with their engine.
The proof is in multiple engine failure from E to G6 engines before and since he made that statement at the meeting I could not attend in USA.
The undeniable proof is the total redesign of the lifter apparatus in the 991.2 GT3/RS - a reversion to the old solid lifter method! This was deployed in the Cup car test engines from as early as 2015, however those negines did not need to rev to 9000 nor be used in a road car. the solid lifters were last used in a Porsche 911 road car with the 964 IIRC!
The flaking DLC coating can indeed cause bore scoring and this is often inspected before PAG will sign off on a new complete engine. In many cases they were just replacing heads if there were no evidence of DLC particulate in the oil filter or scoring of the bores.
The issue of reversion to solid lifters in MA175 engine is unfortunately not as easy as it sounds. The oiling (variable pil pump. oil galleries in the heads and teh ECU software that runs the variable oil pump) was designed on the MA175 for the hydralic lash adjusters (lifters). I suspect by the time you open it up and retrofit the solid valve train gear and address said lubrication to suit you may as well have paid extra for the later 4.0L engine from the 991.2 gen cars.
P.S. It is my firm belief (back by nothing but my speculation) that the change to PDK only in the 991.1 GT3 brought this issue to light far quicker than it would othersie have come to light. the reason being is that a PDK GT3 when driven in Sport Auto mode (like many are0 on teh track is deisgned to lightening shift at 9000 rpm, thus for almost every lap where there is an upshift there will be a 8700-9000 rpm drive train "episode". If you think to using a manual box (I moved from 991.1 GT3 to 981 GT4 and now 991.2 GT3 6speed) you will know form experience that it is virtually impossible to shift at the limiter - so a typical manual driver on the track - even a good one - will typically shift a few hundred rpm shy of the limiter (say 87-8800).
His explanation although correct in the fact that the chosen materials were not up to the task at hand given the situation being imposed by the hydraulic lifters having difficulty to respond with uniformity above 8700 rpm, were misleading by not explaining the route cause - with correct and consistent pressure between the finger follower "pad" and the tip of the camshaft lobe at high rpm - there is actually no need for the metallurgy to be as critical as he has stated.
They tried to use light weight finger followers using MIM (metal injection moulding) and then creating a hard surface without weight sacrifices using DLC (diamond like coating) to give the surface low friction and strength. The theory was sound, however the issues could not control were the adequate oiling of the valvetrain across all cyclinders under sustained high rpm to create consistent pad and lobe contact forces. This is no way a new challenge for automotive manufactuers designing a road car engine that spins beyond 9000 rpm, look at high rpm motor cycle engines as reference. It can be achieved for a 9000 rpm engine but they had already take the worng design path by the time the engine was in production!
Porsche would never admit to a public group they had a fundamental design issue with their engine.
The proof is in multiple engine failure from E to G6 engines before and since he made that statement at the meeting I could not attend in USA.
The undeniable proof is the total redesign of the lifter apparatus in the 991.2 GT3/RS - a reversion to the old solid lifter method! This was deployed in the Cup car test engines from as early as 2015, however those negines did not need to rev to 9000 nor be used in a road car. the solid lifters were last used in a Porsche 911 road car with the 964 IIRC!
The flaking DLC coating can indeed cause bore scoring and this is often inspected before PAG will sign off on a new complete engine. In many cases they were just replacing heads if there were no evidence of DLC particulate in the oil filter or scoring of the bores.
The issue of reversion to solid lifters in MA175 engine is unfortunately not as easy as it sounds. The oiling (variable pil pump. oil galleries in the heads and teh ECU software that runs the variable oil pump) was designed on the MA175 for the hydralic lash adjusters (lifters). I suspect by the time you open it up and retrofit the solid valve train gear and address said lubrication to suit you may as well have paid extra for the later 4.0L engine from the 991.2 gen cars.
P.S. It is my firm belief (back by nothing but my speculation) that the change to PDK only in the 991.1 GT3 brought this issue to light far quicker than it would othersie have come to light. the reason being is that a PDK GT3 when driven in Sport Auto mode (like many are0 on teh track is deisgned to lightening shift at 9000 rpm, thus for almost every lap where there is an upshift there will be a 8700-9000 rpm drive train "episode". If you think to using a manual box (I moved from 991.1 GT3 to 981 GT4 and now 991.2 GT3 6speed) you will know form experience that it is virtually impossible to shift at the limiter - so a typical manual driver on the track - even a good one - will typically shift a few hundred rpm shy of the limiter (say 87-8800).
Edited by Macca993 on Wednesday 6th February 20:33
Macca993 said:
Whilst issues with the 991.1 GT3RS engines are much rarer, they have still occured in instances where the car has been used in Sport Auto mode repeatedly at the track although data points here are very hard to establish.
The key is to go in eyes wide open, the 991.1 GT3/RS engine issues are not a 5% or 10% thing - they will affect ALL cars at some point if driven to redline
Are you sure the problem exists for the .1 RS in the same way? Afaik, the number of engine issues the RS has had is nowhere even close to what gt3 where engine issues started to show almost immediately after the initial stop sale/engine swap. Outside of the odd engine that uses (a heap) of oil and some very early failures that were probably build issues, there's hardly been anything of the sort of engine replacements required in the .1 RS compared to the .1 gt3 that I have heard of or seen and a lot of RS were delivered and tracked in Europe. The key is to go in eyes wide open, the 991.1 GT3/RS engine issues are not a 5% or 10% thing - they will affect ALL cars at some point if driven to redline
P.S and wrt to solid lifters, it's not like they don't (usually) have downsides too. The .2 gt3/rs is seemingly the only high revving engine that will not require reguar valve adjustment....
isaldiri said:
Are you sure the problem exists for the .1 RS in the same way? Afaik, the number of engine issues the RS has had is nowhere even close to what gt3 where engine issues started to show almost immediately after the initial stop sale/engine swap. Outside of the odd engine that uses (a heap) of oil and some very early failures that were probably build issues, there's hardly been anything of the sort of engine replacements required in the .1 RS compared to the .1 gt3 that I have heard of or seen and a lot of RS were delivered and tracked in Europe.
P.S And wrt to solid lifters, it's not like they don't (usually) have downsides too. The .2 GT3/RS is seemingly the only high revving engine that will not require regular valve adjustment....
Interesting P.S And wrt to solid lifters, it's not like they don't (usually) have downsides too. The .2 GT3/RS is seemingly the only high revving engine that will not require regular valve adjustment....
I'd like to see the technical overview with regards to servicing and maintenance of their engines ...In the meantime, consider the Ferrari 458 Italia : 570hp, 9000 rpm, 12.5:1 CR, cam lobes bearing directly onto their respective tappet buckets and they've managed to incorporate hydraulic tappets.
isaldiri said:
Are you sure the problem exists for the .1 RS in the same way? Afaik, the number of engine issues the RS has had is nowhere even close to what gt3 where engine issues started to show almost immediately after the initial stop sale/engine swap. Outside of the odd engine that uses (a heap) of oil and some very early failures that were probably build issues, there's hardly been anything of the sort of engine replacements required in the .1 RS compared to the .1 gt3 that I have heard of or seen and a lot of RS were delivered and tracked in Europe.
P.S and wrt to solid lifters, it's not like they don't (usually) have downsides too. The .2 gt3/rs is seemingly the only high revving engine that will not require reguar valve adjustment....
1). The .1RS MA176 engine benefits from a number of changes that make it far more reliable than the .1 GT3 MA175 in thsi respect - and as you have correctly identified valve train related failure in this engines is very uncommon. Not a concern IMO. Fundamentally the engine architecture still has the same archillies heel. However PAG made an important change prior to launch of the GT3RS. The MA176 4.0L unit was originally intended to redline at 9000 rpm (same as GT3 and subsequent 991.2 GT3RS). I still have screen shots on file from original launch video footage taken at a European track which shows the 991.2 GT3RS with a 9000 rpm tachometer! Porsche elected (wisely) to reduce the headline max rpm to 8800 rpm. Actually this was only for 1st gear. Anyone using a AIM or Racelogic CAN/OBD telemetrics system in their car at teh track chan show you that in 2/3/4/5/6 gear the PDK is limited even further in max rpm and this its shift points for PDK. The shift RPMs are reduced by approx 50 rpm per shift until 8650 rpm. These changes alone reduce significantly the issue of pump down with the hydraulic lash adjusters.P.S and wrt to solid lifters, it's not like they don't (usually) have downsides too. The .2 gt3/rs is seemingly the only high revving engine that will not require reguar valve adjustment....
Furthermore the MA176 engine incorporated the additional oil squirters and galleries in the head that were also incorporated in GT3 G series replacement engines. The variable oil pump had a higher "work rate" capacity and the finder followers were updated to a revised part number and mid cycle MA176 engines incorporated the DLC cam Lobes. Software revisions for oil pump presure at RPM were incorporated as per replacement GT3 engines.
Its my opinion that a valvetrain failure in a MA176 engine even used on track is much much less of a likelihood. Im aware of a couple of examples only.
The 991R engine is unlikely ever to see any signifcant abuse. Most of these cars are used on teh road or are in collections. Porsche took further caution here and reduce the hard limiter further (to 8600 rpm). I dount well ever see an issue with these engines.
I still have incar telemetrics overlayed on video of mysecond engine failing at a track day. You can see clearly the engine get to around 8550 rpm then the MIL light and engine retardation. I then recycled teh ignition in the pits (fault code cleared and all was normal again) and went out again on the track and as soon as I hit 8500 the engine retarted again. A friend on that day wasnt quite so lucky - a few weeks late he went on teh track and his second engine actually broke a finger foller assebnbly and essentially "lunched" its engine.
2). I 100% agree with you on your statement here. Ive been around track and race oriented 911s for many years and owned quite a few myself back to 964 and 993 RS variants. Talking with well known race engine builders in teh industry its my opinion that APs comments "the solid lifters will not need any attention for 200,000km" is absolute BS. OK, my faith has been tested with PAG GT products in recent years for sure - but I and no one I know bettr qualified than I can believe that the 991.2 GT3 used regularly on the track with a solid lifter set up will get away with no lifter adjustmentes for 200,000km. 40-60K km maybe (IIRC the 964 was maybe 30K km inspection). I ahve no idea if the lifters have the same elephant foot type adjuster screws my old 993 race engine had or how they actually are adjusted but Id be VERY VERY surpised if indeed they do not need adjustment within teh first 60-80k km unless maybe teh car is used only for sunday drives on the road etc.
Perhaps we are getting a bit off track here. Ive forgoteen more than I remember about the 991 GT3 engine issue from back in 2014/15. Porsche have this covered by a 10 year engine warranty. Ive helped a number of friends into 991.1 GT3 recently and I believe its a very good car - I personally loved the time I had with mine. However, as stated, I believe that folk just need to be aware of the issues that may present on teh secondary market 5 years from now and buiuld this into their ownership plans.
Macca993 said:
The interesting thing is that many of the 991.1 GT3 sold are to folk who dont hang around forums so know no different from what the OPC selling the car is telling them (or not as the case may be). If the car has passed a Porsche Extended Warranty inspection and been given a futrher few years of cover the dealers dont feel oblidged to tell them anything about the history of their purchase. A point in case is my old car. the new owner knew nothing of the fact it had had three engines and a new set of calipers - he never even asked and he knew nothing of the history of 991 GT3 engine issues!
You'd be surprised. To date, apart from the car I went to see, i have never sat in the drivers seat of any porsche, and i have yet to drive one. My total passenger time is about 5 minutes many years ago. I still have no idea what these finger things are or do, but a quick look and even I was quickly made aware of the engine issue. Edited by Macca993 on Wednesday 6th February 01:41
But there is a huge £ saving on the .1....., and will it really loose as much £ as you would on buying .2 at current prices, when the 10 year warranty is about to expire ? I guess the op has to weigh this up. Yes it will be a pain to sell on, until he drops his asking price accordingly- but over the same time period, depreciation could be significantly less.
pete said:
I'm biased, having just bought a 991.1 GT3...my old Turbo...
Small world Pete; not only did we 'track' each other from TVR Griffith, to 996 turbo, but we now also run GT3's albeit different variants (997.1 and 991.1). To my mind, the issues Porsche are seeing with the M175 engine are extraordinarily similar to those experienced by TVR with their Speed Six.
from 2001: https://www.pistonheads.com/gassing/topic.asp?h=0&...
from 2006: https://www.pistonheads.com/gassing/topic.asp?h=0&...
There too, the factory's use of suspect follwers (cheap crap from India IIRC in the case of Blackpool, rather than new additive manufacturing technology in the case of Stuttgart) was initially thought to be the beginning and end of the issues.... Sadly not.
Digga said:
Small world Pete; not only did we 'track' each other from TVR Griffith, to 996 turbo, but we now also run GT3's albeit different variants (997.1 and 991.1).
To my mind, the issues Porsche are seeing with the M175 engine are extraordinarily similar to those experienced by TVR with their Speed Six.
Hah, yes I'm stalking you via your car history ;-)To my mind, the issues Porsche are seeing with the M175 engine are extraordinarily similar to those experienced by TVR with their Speed Six.
As someone who once replaced every moving part of a Speed Six engine for almost 50% the value of the car, I've no particular desire to do the same on my GT3, hence the warranty. The problems do sound frighteningly similar though: material and manufacturing issues exacerbated by a mechanical design that in hindsight could be considered too ambitious. The difference is that Porsche can apply a lot more money and resources to band-aids such as the DLC coated cams and followers. If the problems are still occurring once engines drop out of the official warranty period, then it will probably be cost effective for a talented independent to come up with more radical solutions, just as Racing Green and TVR Power did for the S6 back in the day.
This sort of recurring problem isn't especially new for Porsche though. My 997.1 GT3 had only 11k miles on the clock when I bought it, yet the engine had already been out of the car 4 times to fix a leaky rear main seal. Not quite as serious as the M175 valve train problem, but a good advert for warranties.
pete said:
Hah, yes I'm stalking you via your car history ;-)
IIRC, in the TVRCC section of the Houx annexe campsite at Le Mans 2002, ours were some of the very few cars sporting the "PistonHeads" stickers at that time. Happy days.
pete said:
This sort of recurring problem isn't especially new for Porsche though. My 997.1 GT3 had only 11k miles on the clock when I bought it, yet the engine had already been out of the car 4 times to fix a leaky rear main seal.
I think they all (M96/7 & Mezger) can give RMS leaks if laid-up for long periods.Gassing Station | 911/Carrera GT | Top of Page | What's New | My Stuff