error code P1325
03-04-2011, 06:12 PM
#32
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On another note, I think I have sourced a good low mileage engine for cheap, so we will probably not even attempt this one. Parts and cheap labor were already over 10k without doing anything else besies a clutch going back in.
03-04-2011, 07:16 PM
#33
Race Director
Sincerely,
Macster.
03-04-2011, 07:25 PM
#34
Three Wheelin'
Macster if you happen to have the book "Porsche 996 the essential companion" the vario cam system is well explain.... Page 169-170-171
Or this explanation from 911hq.com
So what is VarioCam Plus?
Basically VarioCam Plus is a system that uses variable valve timing in conjunction with two stage valve lift on the intake side. As mentioned above the benefits to using this technology is a smother running engine, greater power and torque and better fuel consumption along with lower exhausts emissions.
You could say that this technology makes two engines out of one, in that the system facilitates optimum performance in both normal driving and high speed driving. Despite the chasm between the two driving state, VarioCam Plus achieves this by using the latest in electronic engine management system, which switches perfectly between the two state of driving. The result is greater acceleration and much smother running.
An electro hydraulically switchable tappet is a part of the two stage lift mechanism on each inlet valve. Each of the 12 tappets is made up of two concentric parts; the outer ring and a central shaft, if required, they can be locked together by way of a pin, and this is all done at the command of the engine management system. The result is that the system is now able to vary the valve lift by utilizing two large cams on the outer ring or a smaller cam lobe on the central shaft. This brought about by an electro hydraulic rotary vane adjuster at the head of the respective camshafts which facilitates the seamless timing of each valve.
Another benefit of VarioCam Plus is that it improves the engine's responsiveness during warm up in cold weather; this is accomplishes by selecting the higher lift setting and delaying the valve timing.
When the engine has low loads and medium revs, the lowered valve lift setting is activated which in turns helps to reduce fuel consumption and emissions. The engine's economy is especially improved at lower engine speeds. Conversely, maximum power and torque are achieved when the higher lift setting is selected thus allowing the timing of the valves to advance.
Consequently the engine delivers abundant torque and excellent fuel economy, relative to sports cars with similar sized engines and power output.
Or this explanation from 911hq.com
So what is VarioCam Plus?
Basically VarioCam Plus is a system that uses variable valve timing in conjunction with two stage valve lift on the intake side. As mentioned above the benefits to using this technology is a smother running engine, greater power and torque and better fuel consumption along with lower exhausts emissions.
You could say that this technology makes two engines out of one, in that the system facilitates optimum performance in both normal driving and high speed driving. Despite the chasm between the two driving state, VarioCam Plus achieves this by using the latest in electronic engine management system, which switches perfectly between the two state of driving. The result is greater acceleration and much smother running.
An electro hydraulically switchable tappet is a part of the two stage lift mechanism on each inlet valve. Each of the 12 tappets is made up of two concentric parts; the outer ring and a central shaft, if required, they can be locked together by way of a pin, and this is all done at the command of the engine management system. The result is that the system is now able to vary the valve lift by utilizing two large cams on the outer ring or a smaller cam lobe on the central shaft. This brought about by an electro hydraulic rotary vane adjuster at the head of the respective camshafts which facilitates the seamless timing of each valve.
Another benefit of VarioCam Plus is that it improves the engine's responsiveness during warm up in cold weather; this is accomplishes by selecting the higher lift setting and delaying the valve timing.
When the engine has low loads and medium revs, the lowered valve lift setting is activated which in turns helps to reduce fuel consumption and emissions. The engine's economy is especially improved at lower engine speeds. Conversely, maximum power and torque are achieved when the higher lift setting is selected thus allowing the timing of the valves to advance.
Consequently the engine delivers abundant torque and excellent fuel economy, relative to sports cars with similar sized engines and power output.
03-04-2011, 08:11 PM
#35
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Here are a couple pictures of the cam:
Passenger side. The missing center ring correlates to the groove seen in my early front cam housing picture.
And the driver side intake cam. Notice it still has all 3 rings.
And a little better picture of one of the cam housing brackets. Pretty major crack starting.
Passenger side. The missing center ring correlates to the groove seen in my early front cam housing picture.
And the driver side intake cam. Notice it still has all 3 rings.
And a little better picture of one of the cam housing brackets. Pretty major crack starting.
03-04-2011, 08:39 PM
#36
Race Director
Macster if you happen to have the book "Porsche 996 the essential companion" the vario cam system is well explain.... Page 169-170-171
Or this explanation from 911hq.com
So what is VarioCam Plus?
Basically VarioCam Plus is a system that uses variable valve timing in conjunction with two stage valve lift on the intake side. As mentioned above the benefits to using this technology is a smother running engine, greater power and torque and better fuel consumption along with lower exhausts emissions.
You could say that this technology makes two engines out of one, in that the system facilitates optimum performance in both normal driving and high speed driving. Despite the chasm between the two driving state, VarioCam Plus achieves this by using the latest in electronic engine management system, which switches perfectly between the two state of driving. The result is greater acceleration and much smother running.
An electro hydraulically switchable tappet is a part of the two stage lift mechanism on each inlet valve. Each of the 12 tappets is made up of two concentric parts; the outer ring and a central shaft, if required, they can be locked together by way of a pin, and this is all done at the command of the engine management system. The result is that the system is now able to vary the valve lift by utilizing two large cams on the outer ring or a smaller cam lobe on the central shaft. This brought about by an electro hydraulic rotary vane adjuster at the head of the respective camshafts which facilitates the seamless timing of each valve.
Another benefit of VarioCam Plus is that it improves the engine's responsiveness during warm up in cold weather; this is accomplishes by selecting the higher lift setting and delaying the valve timing.
When the engine has low loads and medium revs, the lowered valve lift setting is activated which in turns helps to reduce fuel consumption and emissions. The engine's economy is especially improved at lower engine speeds. Conversely, maximum power and torque are achieved when the higher lift setting is selected thus allowing the timing of the valves to advance.
Consequently the engine delivers abundant torque and excellent fuel economy, relative to sports cars with similar sized engines and power output.
Or this explanation from 911hq.com
So what is VarioCam Plus?
Basically VarioCam Plus is a system that uses variable valve timing in conjunction with two stage valve lift on the intake side. As mentioned above the benefits to using this technology is a smother running engine, greater power and torque and better fuel consumption along with lower exhausts emissions.
You could say that this technology makes two engines out of one, in that the system facilitates optimum performance in both normal driving and high speed driving. Despite the chasm between the two driving state, VarioCam Plus achieves this by using the latest in electronic engine management system, which switches perfectly between the two state of driving. The result is greater acceleration and much smother running.
An electro hydraulically switchable tappet is a part of the two stage lift mechanism on each inlet valve. Each of the 12 tappets is made up of two concentric parts; the outer ring and a central shaft, if required, they can be locked together by way of a pin, and this is all done at the command of the engine management system. The result is that the system is now able to vary the valve lift by utilizing two large cams on the outer ring or a smaller cam lobe on the central shaft. This brought about by an electro hydraulic rotary vane adjuster at the head of the respective camshafts which facilitates the seamless timing of each valve.
Another benefit of VarioCam Plus is that it improves the engine's responsiveness during warm up in cold weather; this is accomplishes by selecting the higher lift setting and delaying the valve timing.
When the engine has low loads and medium revs, the lowered valve lift setting is activated which in turns helps to reduce fuel consumption and emissions. The engine's economy is especially improved at lower engine speeds. Conversely, maximum power and torque are achieved when the higher lift setting is selected thus allowing the timing of the valves to advance.
Consequently the engine delivers abundant torque and excellent fuel economy, relative to sports cars with similar sized engines and power output.
I do know what VarioCam and VarioCam Plus are, what they do, in a general way.
I have some details on the lower level workings of the VarioCam system in my 02 Boxster. And believe it or not, I have a Turbo intake valve zero-lash lifter at my desk which of course not only provides for zero-lash valve clearance but has the mechanism which is used (under hydraulic control ultimately controlled by the engine controller) to select between the inner or outer lifter portion which changes which of the two different cam lobe profiles -- one a high lift and the other a low lift and with probably different timings as well -- the lifter and ultimately the valve follow.
But what I don't know -- and I hope the 996 Essential... book has this info -- is exactly when exactly under what conditions does the Turbo engine controller decide to advance/retard the intake valve timing and for VarioCam Plus when it does it advance/retard the intake valve timing and when does it switch from reduced lift to high lift or vice versa?
Sincerely,
Macster.
03-04-2011, 10:25 PM
#37
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Macster you have various maps running at once. Throttle request, is a input. Temperature allows the load maps to be enabled. Like when you want "boost" you are actually the ECU to produce more load.
03-05-2011, 10:22 AM
#39
Burning Brakes
So why does this kind of failure happen? could it be human error at assembly? (at Stutgart) maybe they missed that ring on the camshaft? besides changing the oil with 5-40 every other day what else can one do to avoid these failures??
03-05-2011, 01:24 PM
#40
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Doc,
I have it up on stands and I am getting ready to drop the engine. Before I was kinda scared to disassemble my motor. now i'm terrified. Maybe if the Porsche reps see an engine break at 24,000 miles they will take one off the assembly line and send it to Oregon, lol. Please keep us updated on your progress, I know it is going to help me out.
How did the Variocam look? I had the same metal particles on the actuator valve, and was thinking they came from the actuator, on the cam.
Joel
I have it up on stands and I am getting ready to drop the engine. Before I was kinda scared to disassemble my motor. now i'm terrified. Maybe if the Porsche reps see an engine break at 24,000 miles they will take one off the assembly line and send it to Oregon, lol. Please keep us updated on your progress, I know it is going to help me out.
How did the Variocam look? I had the same metal particles on the actuator valve, and was thinking they came from the actuator, on the cam.
Joel
Last edited by joelesmith; 03-05-2011 at 01:43 PM.
03-05-2011, 02:49 PM
#41
Burning Brakes
I'm going to do a little RANT>>> Porsche executives read these threads but they don't offer any solutions. Either on the forum or in private emails. I have torn apart 3 engines with faulty intake tappets >> they FALL apart when you remove the intake camshafts. I have had three customers within the last 3 years require all the lifters and camhousing on one bank replaced. One customer had to replace his head (valve guide got worn beyond spec) I actually received the head for inspection.
Right now we have Doc's engine and Joel's engine along with a customer who I think is near to having his engine removed.
Karl, the metal HAS to go thru the engine. Did this engine have a DUAL MASS flywheel? Guys>> Dual Mass flywheels and the track are NOT good! We are seeing accelerated crankshaft thrust bearing wear. This was reported years ago.
This issue is NOT just contained to the 996TT engine, the 997.1TT will see it also.
Guys change your oil more often, inspect your oil filter and replace the filter at 1/2 your oil change interval. My recommendations are at 5000 miles and more often if you track your car. Filters can be changed at 2500 miles.
Like I mentioned in my previous thread, I offer to my customers that ability to LOCK the intake tappets. There is very little performance LOSS, I can spool the turbochargers quicker and give you back the torque loss in spades. By locking the tappets we reduce the strain on the hydraulic lifters and reduce the failure rates.
Right now we have Doc's engine and Joel's engine along with a customer who I think is near to having his engine removed.
Karl, the metal HAS to go thru the engine. Did this engine have a DUAL MASS flywheel? Guys>> Dual Mass flywheels and the track are NOT good! We are seeing accelerated crankshaft thrust bearing wear. This was reported years ago.
This issue is NOT just contained to the 996TT engine, the 997.1TT will see it also.
Guys change your oil more often, inspect your oil filter and replace the filter at 1/2 your oil change interval. My recommendations are at 5000 miles and more often if you track your car. Filters can be changed at 2500 miles.
Like I mentioned in my previous thread, I offer to my customers that ability to LOCK the intake tappets. There is very little performance LOSS, I can spool the turbochargers quicker and give you back the torque loss in spades. By locking the tappets we reduce the strain on the hydraulic lifters and reduce the failure rates.
Why do you think we are seeing these issues on the tt motors (996, 997), but not on the GT3 cars?
I realize there are a lot less GT3s on the road, and the GT3 has the one piece IMS, but I don't understand why the GT3 motor seems to have less issues...
03-05-2011, 03:18 PM
#42
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Doc,
I have it up on stands and I am getting ready to drop the engine. Before I was kinda scared to disassemble my motor. now i'm terrified. Maybe if the Porsche reps see an engine break at 24,000 miles they will take one off the assembly line and send it to Oregon, lol. Please keep us updated on your progress, I know it is going to help me out.
How did the Variocam look? I had the same metal particles on the actuator valve, and was thinking they came from the actuator, on the cam.
Joel
I have it up on stands and I am getting ready to drop the engine. Before I was kinda scared to disassemble my motor. now i'm terrified. Maybe if the Porsche reps see an engine break at 24,000 miles they will take one off the assembly line and send it to Oregon, lol. Please keep us updated on your progress, I know it is going to help me out.
How did the Variocam look? I had the same metal particles on the actuator valve, and was thinking they came from the actuator, on the cam.
Joel
03-05-2011, 03:19 PM
#43
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The ring was definitely there when the motor was assembled as evidence in the groove in the forward cam housing. From the guys I have talked with, this ring issue is starting to become quite common.
03-09-2011, 07:10 PM
#44
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spent the whole weekend getting the car ready to pull (drop) the engine. I've got just about everything disconnected and drained. any new information on your project. Have you decided to repair the cam actuator or buy a new engine. You said you have end play in the crank, how much is ok and how much is to much?
Joel
Joel
03-09-2011, 09:05 PM
#45
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spent the whole weekend getting the car ready to pull (drop) the engine. I've got just about everything disconnected and drained. any new information on your project. Have you decided to repair the cam actuator or buy a new engine. You said you have end play in the crank, how much is ok and how much is to much?
Joel
Joel