Engine Problems 991 GT3
Discussion
I would appreciate any input from readers who have experienced ongoing engine problems with their 991 GT3s. My car was one of those whose engine was replaced by their local OPC, in my case roughly two years ago. Three months back whilst accelerating fairly hard through the gears, the hose from the coolant reservoir came adrift dumping all the coolant on the road and forcing an immediate stop. The car was recovered to an OPC where the problem was identified and apparently resolved. At the time I asked the OPC to check that the very high temperature the engine immediately reached hadn't resulted in any collateral damage. A week ago, whilst rejoining a motorway and accelerating through the gears, once more fairly hard, a warning light appeared on the dash stating the the engine was operating on reduced power but that continued operation was possible. I continued with my journey parked up at my destination and about 8 hours later on my return journey the warning light was no longer illuminated. The car was immediately dropped off at an OPC. The initial diagnosis was that there may have been a faulty ignition coil. That diagnosis was subsequently discarded and, having made contact with Reading for technical guidance, the OPC speculated that it might be either an issue with tappets or the valves. When I asked whether the incident earlier in the year might have resulted in damage to the valves as a result of the heat the engine reached, the response from the OPC was noncommittal. Apparently Reading are now in touch with the factory for additional assistance in diagnosing the problem but to date there has been no definitive solution offered. Has any other 991 GT3 owner experienced anything similar, and if so how was the problem resolved? I would be grateful for any guidance from fellow 991 GT3 owners who may have experienced similar issues.
porsche nut said:
I would appreciate any input from readers who have experienced ongoing engine problems with their 991 GT3s. My car was one of those whose engine was replaced by their local OPC, in my case roughly two years ago. Three months back whilst accelerating fairly hard through the gears, the hose from the coolant reservoir came adrift dumping all the coolant on the road and forcing an immediate stop. The car was recovered to an OPC where the problem was identified and apparently resolved. At the time I asked the OPC to check that the very high temperature the engine immediately reached hadn't resulted in any collateral damage. A week ago, whilst rejoining a motorway and accelerating through the gears, once more fairly hard, a warning light appeared on the dash stating the the engine was operating on reduced power but that continued operation was possible. I continued with my journey parked up at my destination and about 8 hours later on my return journey the warning light was no longer illuminated. The car was immediately dropped off at an OPC. The initial diagnosis was that there may have been a faulty ignition coil. That diagnosis was subsequently discarded and, having made contact with Reading for technical guidance, the OPC speculated that it might be either an issue with tappets or the valves. When I asked whether the incident earlier in the year might have resulted in damage to the valves as a result of the heat the engine reached, the response from the OPC was noncommittal. Apparently Reading are now in touch with the factory for additional assistance in diagnosing the problem but to date there has been no definitive solution offered. Has any other 991 GT3 owner experienced anything similar, and if so how was the problem resolved? I would be grateful for any guidance from fellow 991 GT3 owners who may have experienced similar issues.
Sorry to hear about this 
I don't have a 991 GT3 but what I would suggest (if you haven't done already) is to make a diary of every issue so far and the response/service you received from the OPC and Porsche Reading. Do this while it is still fresh in your mind and keep this log with every bill/invoice you have received/paid.
It may serve you well if they try to shirk any responsibility.
A friend of mine had a 991 GT3 for around a year. His car had already had the replacement engine (fitted at OPC) before he bought it. He had issues throughout ownership culminating in a further 2 (!) replacement units! One was as a result of coolant loss and overheating and the next after it threw a checklight - I seem to remember a misfire fault which was traced to the valvetrain and in went another new engine!!! He sold the car as soon as engine number 4 was run in!!!
Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
chrisABP said:
A friend of mine had a 991 GT3 for around a year. His car had already had the replacement engine (fitted at OPC) before he bought it. He had issues throughout ownership culminating in a further 2 (!) replacement units! One was as a result of coolant loss and overheating and the next after it threw a checklight - I seem to remember a misfire fault which was traced to the valvetrain and in went another new engine!!! He sold the car as soon as engine number 4 was run in!!!
Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
And as I understand it some cars that have done numerous quick laps of the Ring and are now on their fourth or fifth engines...Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
Not good enough Porsche AG, must try harder. 3/10
chrisABP said:
A friend of mine had a 991 GT3 for around a year. His car had already had the replacement engine (fitted at OPC) before he bought it. He had issues throughout ownership culminating in a further 2 (!) replacement units! One was as a result of coolant loss and overheating and the next after it threw a checklight - I seem to remember a misfire fault which was traced to the valvetrain and in went another new engine!!! He sold the car as soon as engine number 4 was run in!!!
Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
Thanks very much for the response. Whilst I don't want to anticipate the worst, the fact pattern you mention relating to your friend's experience, sounds suspiciously similar to mine.Don't get me wrong we also have lots of other 991 GT3 customers who have never had any issues at all including one who has done nearly 25,000 miles including lots of very quick laps of the Ring!
I am waiting for a further update from the OPC. I will make additional posts in the event that the result of the update warrants it. I should mention in passing that the car has just undergone its first major (2year/12000 mile) service within the past two weeks, during which I specifically requested a further check to ensure no damage resulting from the loss of coolant a few months earlier.
Everything has been well documented so should matters degenerate, which I have no reason to expect they will, I will be well prepared.
porsche nut said:
Thanks very much for the response. Whilst I don't want to anticipate the worst, the fact pattern you mention relating to your friend's experience, sounds suspiciously similar to mine.
I am waiting for a further update from the OPC. I will make additional posts in the event that the result of the update warrants it. I should mention in passing that the car has just undergone its first major (2year/12000 mile) service within the past two weeks, during which I specifically requested a further check to ensure no damage resulting from the loss of coolant a few months earlier.
Everything has been well documented so should matters degenerate, which I have no reason to expect they will, I will be well prepared.
I very doubt they'd do much at your request (regarding this specific issue) whilst the car was in for a service. They'd have three options, check for oil in the coolant expansion tank, water (mayonnaise) in the oil/on the dipstick (if such a thing exists on a 991 GT3 ?) or a cylinder leakdown test to establish the integrity of the head gaskets/ water jacket seals, piston rings and valves. I am waiting for a further update from the OPC. I will make additional posts in the event that the result of the update warrants it. I should mention in passing that the car has just undergone its first major (2year/12000 mile) service within the past two weeks, during which I specifically requested a further check to ensure no damage resulting from the loss of coolant a few months earlier.
Everything has been well documented so should matters degenerate, which I have no reason to expect they will, I will be well prepared.
The latter would have a cost attached to it, and I'm doubtful Porsche would sanction any investigative work without a fault code being read when the diagnostics were plugged into the car.
I hope you get it sorted satisfactorily and without any wriggling from Porsche GB/Stuttgart. I'd brace yourself for another replacement engine on the basis of what you've reported so far :
http://rennlist.com/forums/991-gt3-gt3rs-and-911r/...
Hope I'm wrong ....
Edited by Slippydiff on Thursday 29th September 18:52
So we have E, F and G engines (10th digit in your VIN).
E is the replacement engine for the initial recall (problem with connection rod bolt)
F replacement for the E. No recall here which I find shocking! Seen this first hand. Not enough lubrication in the top end (on the E model) causes camshaft lobe wear. Misfire at about 8500 rpm. Guess only people who really drive it will see this.
G Not sure what changed here but this is the engine in the GT3RS (and late 2015 GT3).
E is the replacement engine for the initial recall (problem with connection rod bolt)
F replacement for the E. No recall here which I find shocking! Seen this first hand. Not enough lubrication in the top end (on the E model) causes camshaft lobe wear. Misfire at about 8500 rpm. Guess only people who really drive it will see this.
G Not sure what changed here but this is the engine in the GT3RS (and late 2015 GT3).
Edited by mm450exc on Thursday 29th September 19:35
Slippydiff said:
porsche nut said:
Thanks very much for the response. Whilst I don't want to anticipate the worst, the fact pattern you mention relating to your friend's experience, sounds suspiciously similar to mine.
I am waiting for a further update from the OPC. I will make additional posts in the event that the result of the update warrants it. I should mention in passing that the car has just undergone its first major (2year/12000 mile) service within the past two weeks, during which I specifically requested a further check to ensure no damage resulting from the loss of coolant a few months earlier.
Everything has been well documented so should matters degenerate, which I have no reason to expect they will, I will be well prepared.
I very doubt they'd do much at your request (regarding this specific issue) whilst the car was in for a service. They'd have three options, check for oil in the coolant expansion tank, water (mayonnaise) in the oil/on the dipstick (if such a thing exists on a 991 GT3 ?) or a cylinder leakdown test to establish the integrity of the head gaskets/ water jacket seals, piston rings and valves. I am waiting for a further update from the OPC. I will make additional posts in the event that the result of the update warrants it. I should mention in passing that the car has just undergone its first major (2year/12000 mile) service within the past two weeks, during which I specifically requested a further check to ensure no damage resulting from the loss of coolant a few months earlier.
Everything has been well documented so should matters degenerate, which I have no reason to expect they will, I will be well prepared.
The latter would have a cost attached to it, and I'm doubtful Porsche would sanction any investigative work without a fault code being read when the diagnostics were plugged into the car.
I hope you get it sorted satisfactorily and without any wriggling from Porsche GB/Stuttgart. I'd brace yourself for another replacement engine on the basis of what you've reported so far :
http://rennlist.com/forums/991-gt3-gt3rs-and-911r/...
Hope I'm wrong ....
Edited by Slippydiff on Thursday 29th September 18:52
http://rennlist.com/forums/991-gt3-gt3rs-and-911r/...
A lot of german guys I've met at the 'ring have had replacement engines after the original 2014 change and the ring taxi 991gt3 has had multiple engines.
Haven't heard of the 991 RS engines having a problem though so perhaps the G series of 991 gt3 engine will finally be reliable even if the rennlist thread above suggests not.
macca_from_rennlist said:
For those new to this thread wishing a synopsis this is an email I wrote to a member today who contacted me by PM...
"Hi There,
Thanks for your email.
Currently, via Rennlist and direct contact I have 35 examples of the CEL engine “misfire code” leading to replacement of complete engines or in a few cases new cam towers with full valve train (top end replacement).
From that rather small sample size 73% are E1 engines and 27% are F engines. E1 simply denotes these engines were the replacement E engines after the stop sale recall in early 2014.
The engines shipped with the early cars (Sept 2013 build through to July 2014) were simply "E" engines followed by a four digit serial number. All E engines were replaces with "E1" engines by June 2014. The issue at the time was "rod bolt failure". A few examples of cars catching fire was the reason for the global recall. These examples had issues within a few hundred miles. Its (unofficially) believed the issue was in the calibration of the air tool used for torquing the titanium fasteners for the rod bolts. The bolts were designed with a very narrow torque tolerance and the tool was unable to maintain calibration to this specification on the production line. The replacement rod bolts were engineered beyond original specification to handle production line tool calibration variances and the tool itself was subject to frequent calibration checks. They are understood to be the rod bolts that feature in the later RS engine.
E engines had the first generation DLC "finger" rockers/followers. Later F engines we believe had a revised DLC coating on their DLC rockers and what appears to be a revision of oil pressure in the mid rpm range via the ECU. The oil pump in these cars is electronically variable and controlled by the ECU. The finger rockers are Metal Injection Molding (MIM) formed, the alloy constituency unknown but they are light and then coated with a diamond like layer for hardness and durability...
E1 cars were back on the road in Europe and USA from June/July 2014 in time for the European and North American summer and traditional “track season”. These cars are now in their third such season of useage by those who track their cars frequently.
The F serial cars started to be delivered to clients by September 2015. As such they have seen the equivalent of just over one season of use on the track at this time.
With such a small sample base (I personally believe there are around 10x the failures We have knowledge of) and with the F engines having been introduced relatively recently it's difficult to make predictions.
However in September 2016 "G" serial (and e fine)cars started to be delivered to customers. These cars were only in production for approx. 4 months and coincided with deliveries of the first 991 RS which was also G serial. I believe around 3-400 G series GT3 were produced by the factory until production ceased mid Dec 2015.
With the G serial cars Porsche appears to have made updates to the GT3 MA175 engine to match identically (other than crank and 4.0L capacity related components) the RS MA176 engines.
The G engines have re designed heads which include additional oiling galleries. The pump has been updated to a unit for which the higher oil pressures on these cars make up a smaller percentage of their total capability (known as "duty cycle"). This is not to say the E/F oil pumps are inadequate, simply that the pump is now working less to maintain the increased pressure which I guess may aid in long term reliability. Not an issue as I believe as the original pump was already up to the job. ECU software for mid range oil pressure was further revised. Its very likely a third revision of the DLC coated rockers was also used, however this has not yet been confirmed. A new oil filter and neck specific to the G series is fitted.
We have no specific examples of failures of G engines in GT3 and RS at this time, however I have been contacted by a German fellow claiming his G engine RS has suffered the misfire code and its currently being looked at by Porsche. He is in his second European track season with the car as it was one of the first delivered in July 2015 (European cars only take a few days from factory to dealer unlike cars sent by sea to far away markets). I also have a 2nd/3rd hand claim of a European GT3 G series that may have had the same failure. It was a car used in the Porsche race series over in Germany in anger any and an early delivery so its in its 2nd season. However Ive learned not to rely on "here-say", as so far many stories have turned out to be wrong (i.e. it was an F engine "failure" not a G or the issue was unrelated to the valve train etc).
Subsequent we learn in May 2016 that a new engine "G1" is built as a swap replacement for engine issues. It has changes, primarily DLC coated cams (the lobes). This engine is installed in June onward 911RS builds and the new 911R & of course in the 4.0L capacity but the same changes apply. We have evidence of this through photos and the Porsche parts catalogue (PET) and invoices for supply of parts to a German GT3 owner who has just had updated heads fitted with these parts on his E engine.
My advice to you? If Im honest I will tell you I am not confident that Porsche have a 100% handle on the valve train wear issue in the GT3 & RS yet. But I suspect they must be getting close. They have played with the rockers, then the oiling and now the cam lobes. I think they must be very close to addressing this but my confidence has been eroded over three years so I cannot say this is certain.
If I were in the market for a 991 GT3 (great car by the way, you will love it!) and I had intentions to drive it on the track, I would look for an early E series car that has not yet had the engine or heads replaced that carries the longest possible warranty. Some cars were given extended factory warranty until 2019. I would drive it hard at the track understanding it will at some point need a new engine/heads. My theory is you will be given the latest update at that time, a fix I believe is superior to the E and F engines. Infact you will have the very latest tech likely shared by the 911R and 991.2 engines to come depending on when the engine shows the issue. The track warranty and extended duration of warranty are the comfort and the price for earlier higher mileage cars would be less. I would not be concerned about mileage. Low mileage cars will take longer for you to receive your updated parts and enjoy full piece of mind.
The other option is to try and find a G series car. They will be expensive and as demonstrated do not have the "last word" in updates. They could take many years to show the fault and be out of warranty when that happens. I now have the G engine from Feb and fall into this camp. I wish now my E1 engine had hung on for longer so I could today have the G1 engine replacement!
So in summery, its my speculative belief that over a long enough time all E & F engines will exhibit the issue dependent on use and mileage. The F engines do appear more robust but the time line is mucking up the stats and if its taken out long enough I suspect the outcome will be the same failure rate %. The G engines is one supposes more reliable again but much newer with less time on it to show the issues just yet, especially with RS cars which are not tracked with as much volume/frequency and have a lower redline. These "G" RS cars too will exhibit the issue over time. We know for fact that the G series RS & GT3 cannot be 100% bullet proof as PAG have released the G1 engine with further updates. To be honest I don't think they will know exactly how well their changes are tracking till well into 991.2 GT3 production and thus one reason Im not running out to order next gen GT3 at this time. Id rather deal with what I know..."
"Hi There,
Thanks for your email.
Currently, via Rennlist and direct contact I have 35 examples of the CEL engine “misfire code” leading to replacement of complete engines or in a few cases new cam towers with full valve train (top end replacement).
From that rather small sample size 73% are E1 engines and 27% are F engines. E1 simply denotes these engines were the replacement E engines after the stop sale recall in early 2014.
The engines shipped with the early cars (Sept 2013 build through to July 2014) were simply "E" engines followed by a four digit serial number. All E engines were replaces with "E1" engines by June 2014. The issue at the time was "rod bolt failure". A few examples of cars catching fire was the reason for the global recall. These examples had issues within a few hundred miles. Its (unofficially) believed the issue was in the calibration of the air tool used for torquing the titanium fasteners for the rod bolts. The bolts were designed with a very narrow torque tolerance and the tool was unable to maintain calibration to this specification on the production line. The replacement rod bolts were engineered beyond original specification to handle production line tool calibration variances and the tool itself was subject to frequent calibration checks. They are understood to be the rod bolts that feature in the later RS engine.
E engines had the first generation DLC "finger" rockers/followers. Later F engines we believe had a revised DLC coating on their DLC rockers and what appears to be a revision of oil pressure in the mid rpm range via the ECU. The oil pump in these cars is electronically variable and controlled by the ECU. The finger rockers are Metal Injection Molding (MIM) formed, the alloy constituency unknown but they are light and then coated with a diamond like layer for hardness and durability...
E1 cars were back on the road in Europe and USA from June/July 2014 in time for the European and North American summer and traditional “track season”. These cars are now in their third such season of useage by those who track their cars frequently.
The F serial cars started to be delivered to clients by September 2015. As such they have seen the equivalent of just over one season of use on the track at this time.
With such a small sample base (I personally believe there are around 10x the failures We have knowledge of) and with the F engines having been introduced relatively recently it's difficult to make predictions.
However in September 2016 "G" serial (and e fine)cars started to be delivered to customers. These cars were only in production for approx. 4 months and coincided with deliveries of the first 991 RS which was also G serial. I believe around 3-400 G series GT3 were produced by the factory until production ceased mid Dec 2015.
With the G serial cars Porsche appears to have made updates to the GT3 MA175 engine to match identically (other than crank and 4.0L capacity related components) the RS MA176 engines.
The G engines have re designed heads which include additional oiling galleries. The pump has been updated to a unit for which the higher oil pressures on these cars make up a smaller percentage of their total capability (known as "duty cycle"). This is not to say the E/F oil pumps are inadequate, simply that the pump is now working less to maintain the increased pressure which I guess may aid in long term reliability. Not an issue as I believe as the original pump was already up to the job. ECU software for mid range oil pressure was further revised. Its very likely a third revision of the DLC coated rockers was also used, however this has not yet been confirmed. A new oil filter and neck specific to the G series is fitted.
We have no specific examples of failures of G engines in GT3 and RS at this time, however I have been contacted by a German fellow claiming his G engine RS has suffered the misfire code and its currently being looked at by Porsche. He is in his second European track season with the car as it was one of the first delivered in July 2015 (European cars only take a few days from factory to dealer unlike cars sent by sea to far away markets). I also have a 2nd/3rd hand claim of a European GT3 G series that may have had the same failure. It was a car used in the Porsche race series over in Germany in anger any and an early delivery so its in its 2nd season. However Ive learned not to rely on "here-say", as so far many stories have turned out to be wrong (i.e. it was an F engine "failure" not a G or the issue was unrelated to the valve train etc).
Subsequent we learn in May 2016 that a new engine "G1" is built as a swap replacement for engine issues. It has changes, primarily DLC coated cams (the lobes). This engine is installed in June onward 911RS builds and the new 911R & of course in the 4.0L capacity but the same changes apply. We have evidence of this through photos and the Porsche parts catalogue (PET) and invoices for supply of parts to a German GT3 owner who has just had updated heads fitted with these parts on his E engine.
My advice to you? If Im honest I will tell you I am not confident that Porsche have a 100% handle on the valve train wear issue in the GT3 & RS yet. But I suspect they must be getting close. They have played with the rockers, then the oiling and now the cam lobes. I think they must be very close to addressing this but my confidence has been eroded over three years so I cannot say this is certain.
If I were in the market for a 991 GT3 (great car by the way, you will love it!) and I had intentions to drive it on the track, I would look for an early E series car that has not yet had the engine or heads replaced that carries the longest possible warranty. Some cars were given extended factory warranty until 2019. I would drive it hard at the track understanding it will at some point need a new engine/heads. My theory is you will be given the latest update at that time, a fix I believe is superior to the E and F engines. Infact you will have the very latest tech likely shared by the 911R and 991.2 engines to come depending on when the engine shows the issue. The track warranty and extended duration of warranty are the comfort and the price for earlier higher mileage cars would be less. I would not be concerned about mileage. Low mileage cars will take longer for you to receive your updated parts and enjoy full piece of mind.
The other option is to try and find a G series car. They will be expensive and as demonstrated do not have the "last word" in updates. They could take many years to show the fault and be out of warranty when that happens. I now have the G engine from Feb and fall into this camp. I wish now my E1 engine had hung on for longer so I could today have the G1 engine replacement!
So in summery, its my speculative belief that over a long enough time all E & F engines will exhibit the issue dependent on use and mileage. The F engines do appear more robust but the time line is mucking up the stats and if its taken out long enough I suspect the outcome will be the same failure rate %. The G engines is one supposes more reliable again but much newer with less time on it to show the issues just yet, especially with RS cars which are not tracked with as much volume/frequency and have a lower redline. These "G" RS cars too will exhibit the issue over time. We know for fact that the G series RS & GT3 cannot be 100% bullet proof as PAG have released the G1 engine with further updates. To be honest I don't think they will know exactly how well their changes are tracking till well into 991.2 GT3 production and thus one reason Im not running out to order next gen GT3 at this time. Id rather deal with what I know..."
Thanks very much, this is incredibly helpful.
I think I can guess what the next conversation with the OPC will be about.
My thanks to everyone who has responded to my original post.
I think I can guess what the next conversation with the OPC will be about.
My thanks to everyone who has responded to my original post.
isaldiri said:
this is a thread you'll probably want to be reading as well OP...
http://rennlist.com/forums/991-gt3-gt3rs-and-911r/...
A lot of german guys I've met at the 'ring have had replacement engines after the original 2014 change and the ring taxi 991gt3 has had multiple engines.
Haven't heard of the 991 RS engines having a problem though so perhaps the G series of 991 gt3 engine will finally be reliable even if the rennlist thread above suggests not.
http://rennlist.com/forums/991-gt3-gt3rs-and-911r/...
A lot of german guys I've met at the 'ring have had replacement engines after the original 2014 change and the ring taxi 991gt3 has had multiple engines.
Haven't heard of the 991 RS engines having a problem though so perhaps the G series of 991 gt3 engine will finally be reliable even if the rennlist thread above suggests not.
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