996 vs. 997 M96
#1
Burning Brakes
Thread Starter
Join Date: Dec 2003
Location: Arlington, VA
Posts: 821
Likes: 0
Received 0 Likes
on
0 Posts
996 vs. 997 M96
While thinking about Keith's concern in the engine replacement thread, something occured to me. A quick Google query shows that the 997 uses an evolution of the same M96 block. If Porsche didn't fix the grenading motors completely with the 3.6, doesn't that mean one of two things?
a) The engine has a design or manufacturing defect that Porsche has not found, and thus 997 engines can potentially blow up, too.
or
b) The engine has a design or manufacturing defect that Porsche has found and corrected, but refuses to take responsibility for on the 996?
Justin
a) The engine has a design or manufacturing defect that Porsche has not found, and thus 997 engines can potentially blow up, too.
or
b) The engine has a design or manufacturing defect that Porsche has found and corrected, but refuses to take responsibility for on the 996?
Justin
#2
Newbies Hospitality Director
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Join Date: Apr 2005
Location: Winston-Salem, NC
Posts: 18,084
Likes: 0
Received 33 Likes
on
33 Posts
Justin - interesting thought! Of the two choices given, I would "guess" that B is the case. I spend almost as much time on the 997 Forum as I do here on the 996 Forum and I have heard of very few 997 engines grenading. Maybe Porsche did correct the manufacturing defect in the latesr version of the M96 block.
#3
I'd say the answer is probably A.
Although they may have "modified" the design, the 997 motors still appear to have the same RMS issues. It seems like Porsche feels it's less expensive to "repair" the RMS than to rework the architecture of the engine.
Although they may have "modified" the design, the 997 motors still appear to have the same RMS issues. It seems like Porsche feels it's less expensive to "repair" the RMS than to rework the architecture of the engine.
#4
Rennlist Member
RMS isn't and has never been the reason of an engine failure. do a search. The 997, GT3s, 996 and Boxster/Cayman all continue to have leaks from the rear main seal which is corrected by putting in a new seal.
#5
Rennlist Member
As a new 996 owner('02 C4 cab), I am just now being made aware of what I bought. I assumed at this stage of 911 evolution, Porsche would have refined and sorted out these cars. Can I assume that RMS is the Rear Main Seal, and that these 996 motors are prone to leak, fail or blow up?
In reading thru many of these threads, it is also apparent that the best thing to do is to drive these cars in the manner in which they were intended to be driven- somewhat agressive and pushing the RPM's up to reasonable levels.
Do I own a 'ticking time bomb'?
I also have a pair of Audi D2 S8's, and they have tranny issues that I'm well aware of and prepared to deal with. Should I worry about my C4, or just continue to love it and drive it like I stole it?
Thanks, guys.
Jim
In reading thru many of these threads, it is also apparent that the best thing to do is to drive these cars in the manner in which they were intended to be driven- somewhat agressive and pushing the RPM's up to reasonable levels.
Do I own a 'ticking time bomb'?
I also have a pair of Audi D2 S8's, and they have tranny issues that I'm well aware of and prepared to deal with. Should I worry about my C4, or just continue to love it and drive it like I stole it?
Thanks, guys.
Jim
#6
Burning Brakes
Thread Starter
Join Date: Dec 2003
Location: Arlington, VA
Posts: 821
Likes: 0
Received 0 Likes
on
0 Posts
Keep in mind RMS is isn't what I was referring to.
It just seems like either Porsche was/is screwing 996 owners, or they're about to go through it again with 997 owners. One of two things pretty much has to be the case, doesn't it?
Jim,
Drive it like you stole it. Refer to the "Engine replacement" thread. Personally, I think the odds are heavily in your favor that you will be in very good shape and nothing will ever happen. There is a small chance something will happen, but that's true of any car, and shouldn't deter you from the wonderful one you already have!
It just seems like either Porsche was/is screwing 996 owners, or they're about to go through it again with 997 owners. One of two things pretty much has to be the case, doesn't it?
Jim,
Drive it like you stole it. Refer to the "Engine replacement" thread. Personally, I think the odds are heavily in your favor that you will be in very good shape and nothing will ever happen. There is a small chance something will happen, but that's true of any car, and shouldn't deter you from the wonderful one you already have!
#7
Burning Brakes
Originally Posted by skiracer
Do I own a 'ticking time bomb'?
While early engines had some problems, the IMS failure is the thing that kills an engine regardless of year. It is unnerving, but no one is able to assess its frequency, and as is typical, Porsche won't say.
My assessment is that it can't be that bad because you can buy an extended warranty, and those companies should know.
My factory warranty ends early next year. I think I will buy a four year powertrain warranty for peace of mind as my solution. I should not have to, but the alternative is to sell the car.
Trending Topics
#8
Rennlist Member
Thanks, guys. I will drive it and hope for the best. I decided against an aftermarket warranty, because I figured the 911 was going to be rock solid and live up to its reputation for reliability. Now I am reconsidering.
Any thoughts? Any suggestions on a warranty provider? I tend to be very risk tolerant by nature.
Any thoughts? Any suggestions on a warranty provider? I tend to be very risk tolerant by nature.
#9
Banned
If you're so risk tolerant, then why are you even considering a warranty in all honesty?
Go through your local Porsche dealer since they're going to likely be the ones you want to request a new engine from should you even come to that crossroad.
Is peace of mind worth $3500 to you? Sounds to me that you do want coverage. I like risk, but this is a stupid risk to take on. Get the warranty, be done with it. You'll feel better.
Go through your local Porsche dealer since they're going to likely be the ones you want to request a new engine from should you even come to that crossroad.
Is peace of mind worth $3500 to you? Sounds to me that you do want coverage. I like risk, but this is a stupid risk to take on. Get the warranty, be done with it. You'll feel better.
#10
Actually the 997 block is the same, as are the crank rods, heads, cams and intake manifolds. The only differences between the 997 engine and the 996 is different accessory routing, intake airbox and exhaust routing. Yes the rear main seal and clutch were revised on the 997, but those parts are now the current service replacements for the 996 through your Porsche dealer. The different intake box and ECU tuning are the differences for the minor 5 hp (but no torque) increase in the rating of the 997.
Both the 997 Carrera and Carrera S use revised versions of the M96 transmission. The differences aren't to beef up the gearbox, but rather just re-gearing to compensate for the overall drive ratio change due to adding taller rear tires on the 997. They shortened all the gears so the overall drive ratio in every gear basically matches the previous 996. This is the primary reason why despite having slight more power and a slightly lower coeficient of drag, the 997 Carrera has the same gear limited top speed as the previous 996.
The RMS is not going to cause an engine to blow up unless it is allowed to seap enough that the engine starves for oil (owner negligence). There were some production issues Porsche has admitted. In the early 2003 production, due to a faulty torque wrench many of the cars had timing chain tensioners that were improperly torqued and failed.
Intermediate shafts and shaft bearing can also fail. This is ususally a slow process and is preceeded by an IMS leak. If it isn't fixed at the first sign of a problem, it can easily result in valves hitting pistons and an engine replacement down the line. Being intelligent and dealing with issues when they occur and not waiting can easily prevent a major issue down the line. so, not these cars are not ticking time bombs.
That doesn't mean there aren't others out there that are. The 01-02' M3's really are a ticking timebomb. BMW designed an oiling system tht starves those engines at high rpms. They admitted and fixed the problem in 03'. Unfortunately, with an older can that has not had the issue corrected and is driven hard is just rolling the dice everytime on it blowing.
Both the 997 Carrera and Carrera S use revised versions of the M96 transmission. The differences aren't to beef up the gearbox, but rather just re-gearing to compensate for the overall drive ratio change due to adding taller rear tires on the 997. They shortened all the gears so the overall drive ratio in every gear basically matches the previous 996. This is the primary reason why despite having slight more power and a slightly lower coeficient of drag, the 997 Carrera has the same gear limited top speed as the previous 996.
The RMS is not going to cause an engine to blow up unless it is allowed to seap enough that the engine starves for oil (owner negligence). There were some production issues Porsche has admitted. In the early 2003 production, due to a faulty torque wrench many of the cars had timing chain tensioners that were improperly torqued and failed.
Intermediate shafts and shaft bearing can also fail. This is ususally a slow process and is preceeded by an IMS leak. If it isn't fixed at the first sign of a problem, it can easily result in valves hitting pistons and an engine replacement down the line. Being intelligent and dealing with issues when they occur and not waiting can easily prevent a major issue down the line. so, not these cars are not ticking time bombs.
That doesn't mean there aren't others out there that are. The 01-02' M3's really are a ticking timebomb. BMW designed an oiling system tht starves those engines at high rpms. They admitted and fixed the problem in 03'. Unfortunately, with an older can that has not had the issue corrected and is driven hard is just rolling the dice everytime on it blowing.
#11
Drifting
Originally Posted by 02 Carrera
...
Intermediate shafts and shaft bearing can also fail. This is ususally a slow process and is preceeded by an IMS leak. If it isn't fixed at the first sign of a problem, it can easily result in valves hitting pistons and an engine replacement down the line. Being intelligent and dealing with issues when they occur and not waiting can easily prevent a major issue down the line. so, not these cars are not ticking time bombs.
....
Intermediate shafts and shaft bearing can also fail. This is ususally a slow process and is preceeded by an IMS leak. If it isn't fixed at the first sign of a problem, it can easily result in valves hitting pistons and an engine replacement down the line. Being intelligent and dealing with issues when they occur and not waiting can easily prevent a major issue down the line. so, not these cars are not ticking time bombs.
....
from what i've seen (on the internet ) most time it just happend without any warning sign....
#12
Burning Brakes
Originally Posted by justinmm2
While thinking about Keith's concern in the engine replacement thread, something occured to me. A quick Google query shows that the 997 uses an evolution of the same M96 block. If Porsche didn't fix the grenading motors completely with the 3.6, doesn't that mean one of two things?
a) The engine has a design or manufacturing defect that Porsche has not found, and thus 997 engines can potentially blow up, too.
or
b) The engine has a design or manufacturing defect that Porsche has found and corrected, but refuses to take responsibility for on the 996?
Justin
a) The engine has a design or manufacturing defect that Porsche has not found, and thus 997 engines can potentially blow up, too.
or
b) The engine has a design or manufacturing defect that Porsche has found and corrected, but refuses to take responsibility for on the 996?
Justin
#13
Drifting
Originally Posted by DCP
RMS failure was common, but will not cause engine failure. Porsche used to replace engines which suffered chronic RMS failures, but it was not because the engine itself failed. The current version of the RMS seems to work much better than the previous versions. RMS is just not a big deal.
#14
Drifting
Originally Posted by 02 Carrera
That doesn't mean there aren't others out there that are. The 01-02' M3's really are a ticking timebomb. BMW designed an oiling system tht starves those engines at high rpms. They admitted and fixed the problem in 03'. Unfortunately, with an older can that has not had the issue corrected and is driven hard is just rolling the dice everytime on it blowing.
The incidence of failed engines in 04-06 M3's is close to zero, unless caused by driver error such as missed shift causing mechanical engine over rev. By the way, BMW issued a 6 yr./100.000 mile engine warranty to any owner with a M3 effected by the connecting rod bearing recall. Wonder if Porsche has done anything like that.
#15
Burning Brakes
Originally Posted by GSIRM3
It is not a big deal as long as the car is still under warranty when it fails. While it won't cause engine failure, it is expensive to repair.