My spun camshaft story
10-23-2015, 10:43 AM
#47
Burning Brakes
10-23-2015, 11:02 AM
#49
Race Director
10-23-2015, 11:05 AM
#50
Burning Brakes
BTW for others who are interested, you need to click on his name, then go to "view user profile", find the drop down menu under "user lists" and click "add to ignore list".
10-23-2015, 11:06 AM
#51
Burning Brakes
10-23-2015, 11:39 AM
#52
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Well I will tell you I've owned my 07 TT for slightly over one year now and I've had the catastrophic coolant failure, spun camshaft, and oil leak all within one year. As a result my car has spent more than 4-5 months at the dealer getting repaired out of the year i've owned it. All covered under CPO thank goodness. These things do happen so don't point Speed 21 to be crazy, annoying maybe but not crazy. :-)
10-23-2015, 01:02 PM
#53
The Camshaft issue happened to me some time ago. I have it on good authority (his opinion) by someone who builds a lot of these engines that the issues are several. This is what I was told.
All of these engines Turbo and NA have an inherent harmonic issue at low to mid RPM's. The vibrations travel from the Crankshaft up through the chain drives into the valve train. The sleeve that turns is pressed into the end of the camshaft. The same high frequency vibrations cause the sleeves to come loose. The same vibrations causes havoc with Cam timing as well.
He told me that when they regrind the cam profiles they used to remove these sleeves. Some were tighter than others to remove. When measuring the bore in the end of the camshaft, it was found that some bores were bigger than others. This was put down to production tolerances. Maybe this is why some come loose and others don't. The sleeves have an interference fit into the end of the camshaft that should be a minimum which I cannot remember what he said. Sorry.
I was also told that some cars are driven more at the certain engine speeds in the harmonic range. Turbo engines produce a higher toque pulse due to higher cylinder pressures which increases the harmonic forces.
Race engines do not have variable Camshaft control. Recommended fix is to fit the Crankshaft damper and control the harmonics.
All of these engines Turbo and NA have an inherent harmonic issue at low to mid RPM's. The vibrations travel from the Crankshaft up through the chain drives into the valve train. The sleeve that turns is pressed into the end of the camshaft. The same high frequency vibrations cause the sleeves to come loose. The same vibrations causes havoc with Cam timing as well.
He told me that when they regrind the cam profiles they used to remove these sleeves. Some were tighter than others to remove. When measuring the bore in the end of the camshaft, it was found that some bores were bigger than others. This was put down to production tolerances. Maybe this is why some come loose and others don't. The sleeves have an interference fit into the end of the camshaft that should be a minimum which I cannot remember what he said. Sorry.
I was also told that some cars are driven more at the certain engine speeds in the harmonic range. Turbo engines produce a higher toque pulse due to higher cylinder pressures which increases the harmonic forces.
Race engines do not have variable Camshaft control. Recommended fix is to fit the Crankshaft damper and control the harmonics.
10-23-2015, 03:23 PM
#55
L Perm, The oils today don't foam and have anti foam agents like calcium in there formulation. All the oil is stored in the large reservoir. The scavenge pump pulls the oil out of the engine case at a very high rate. The oil is pumped to the main reservoir. The second stage or pressure stage of the oil pump pulls oil from the reservoir tank, and supplies oil under pressure to all the engine components>> crankshaft, turbochargers, vario-cam module and lifters... There is no chance of foam or oil starvation... You have all the oil stored in the reservoir.
This failure is a mechanical material/engineering failure. A stamped steel sleeve that is pressed into a cast iron camshaft rotates inside the hollow camshaft bore. It's random with zero notice or pattern. It's like a lottery.
There are a few theory's as to why the sleeve is turning, but they are unrelated to engine oil or lubrication as the cause.. However, when the sleeves turn, they do affect the oil movement to the variocam module..
This failure is a mechanical material/engineering failure. A stamped steel sleeve that is pressed into a cast iron camshaft rotates inside the hollow camshaft bore. It's random with zero notice or pattern. It's like a lottery.
There are a few theory's as to why the sleeve is turning, but they are unrelated to engine oil or lubrication as the cause.. However, when the sleeves turn, they do affect the oil movement to the variocam module..
There are some who swear that Rotella, et al. are a bad idea, and some that swear there's nothing better. No real evidence offered by anyone.
I'm pulling my 928 engine tomorrow and will be disassembling the heads to some extent. I'll see what the tappets/cams look like, having used Mobile 1 15w-50. I haven't had any problems--just changing the head gaskets and chain tensioner pads.
Louis
10-23-2015, 03:42 PM
#56
Burning Brakes
Well I will tell you I've owned my 07 TT for slightly over one year now and I've had the catastrophic coolant failure, spun camshaft, and oil leak all within one year. As a result my car has spent more than 4-5 months at the dealer getting repaired out of the year i've owned it. All covered under CPO thank goodness. These things do happen so don't point Speed 21 to be crazy, annoying maybe but not crazy. :-)
YMMV but the block function is sweeeeeeeeeeeet
10-23-2015, 04:45 PM
#57
Drifting
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Well I will tell you I've owned my 07 TT for slightly over one year now and I've had the catastrophic coolant failure, spun camshaft, and oil leak all within one year. As a result my car has spent more than 4-5 months at the dealer getting repaired out of the year i've owned it. All covered under CPO thank goodness. These things do happen so don't point Speed 21 to be crazy, annoying maybe but not crazy. :-)
Luckily my P011 code was just carbon build up on the cam sensors (dealer told me). Hoping this never comes back
10-23-2015, 05:02 PM
#58
All cars will have wear and tears and eventually break down at one point, PCCB brakes cost $8-10k, clutch cost $3-5k, PDK cost $10-$15k, spun cam $6-$8k, coolant can be pinned and fixed $3-$5k but it is the price to own luxury high performance cars. I knew Porsche will cost more than Honda parts/labor, but it is the price you gotta pay to play. 9A1 engines still have a few more years and thousands more miles to test it reliability but Mezger has history and heritage. Would I buy another 997TT after knowing all these issues, the answer is "HELL YEAH"
Revise, my SA just called and it was the charcoal canister which is part of the emission cleaning system, no big deal and let not make everyone scare of the camshaft issue. Got a clean bill of health now.
Revise, my SA just called and it was the charcoal canister which is part of the emission cleaning system, no big deal and let not make everyone scare of the camshaft issue. Got a clean bill of health now.
Last edited by gotgolf52; 10-23-2015 at 06:16 PM.
10-23-2015, 07:14 PM
#59
I guess everyone is entitled to an opinion so long as it doesn't interfere with the integrity of their own vehicles track record of reliability, or in this case lack thereof.
Anyway, hope your problem doesn't re surface. I hear it can if the pinning exercise was not employed. It is after all an inherent problem it would appear.
1. yes, people have spun camshafts. I've heard of maybe a dozen examples. Since you know this is a common problem, you have statistics. post them.
2. Sometimes I sure do.
Your post proves you have no objective data and go by what you read on forums. While not always false, where are the numbers. How many 997.1TTs have failed? How many 9A1s have failed?
FACTS....
2. Sometimes I sure do.
Your post proves you have no objective data and go by what you read on forums. While not always false, where are the numbers. How many 997.1TTs have failed? How many 9A1s have failed?
FACTS....
10-23-2015, 07:46 PM
#60
So make no mistake, I wear my banning at 6 like a badge of honor
Well I will tell you I've owned my 07 TT for slightly over one year now and I've had the catastrophic coolant failure, spun camshaft, and oil leak all within one year. As a result my car has spent more than 4-5 months at the dealer getting repaired out of the year i've owned it. All covered under CPO thank goodness. These things do happen so don't point Speed 21 to be crazy, annoying maybe but not crazy. :-)
The Camshaft issue happened to me some time ago. I have it on good authority (his opinion) by someone who builds a lot of these engines that the issues are several. This is what I was told.
All of these engines Turbo and NA have an inherent harmonic issue at low to mid RPM's. The vibrations travel from the Crankshaft up through the chain drives into the valve train. The sleeve that turns is pressed into the end of the camshaft. The same high frequency vibrations cause the sleeves to come loose. The same vibrations causes havoc with Cam timing as well.
He told me that when they regrind the cam profiles they used to remove these sleeves. Some were tighter than others to remove. When measuring the bore in the end of the camshaft, it was found that some bores were bigger than others. This was put down to production tolerances. Maybe this is why some come loose and others don't. The sleeves have an interference fit into the end of the camshaft that should be a minimum which I cannot remember what he said. Sorry.
I was also told that some cars are driven more at the certain engine speeds in the harmonic range. Turbo engines produce a higher toque pulse due to higher cylinder pressures which increases the harmonic forces.
Race engines do not have variable Camshaft control. Recommended fix is to fit the Crankshaft damper and control the harmonics.
All of these engines Turbo and NA have an inherent harmonic issue at low to mid RPM's. The vibrations travel from the Crankshaft up through the chain drives into the valve train. The sleeve that turns is pressed into the end of the camshaft. The same high frequency vibrations cause the sleeves to come loose. The same vibrations causes havoc with Cam timing as well.
He told me that when they regrind the cam profiles they used to remove these sleeves. Some were tighter than others to remove. When measuring the bore in the end of the camshaft, it was found that some bores were bigger than others. This was put down to production tolerances. Maybe this is why some come loose and others don't. The sleeves have an interference fit into the end of the camshaft that should be a minimum which I cannot remember what he said. Sorry.
I was also told that some cars are driven more at the certain engine speeds in the harmonic range. Turbo engines produce a higher toque pulse due to higher cylinder pressures which increases the harmonic forces.
Race engines do not have variable Camshaft control. Recommended fix is to fit the Crankshaft damper and control the harmonics.
At last!! Some intelligent technical information being offered without emotionally charged "drivel" and personal hate fests.
Where engine failures are concerned there is always a reason for everything and it is finding that reason that is of greatest interest to me. This information brings it one step closer!
Last edited by speed21; 10-23-2015 at 08:37 PM.