Snapped Camshaft Adjuster Bolt = Engine & Brake Hydraulics Failure ?
#213
09-28-2016, 09:48 AM
Registered User
It's ongoing.. there will hopefully be a report by the weekend..
#214
09-28-2016, 05:14 PM
started my car up today, waited around 2 min while checking google maps, pulled out of the parking structure and go a check engine light.
called the dealer, will be there at 8am for them to take a look at. stopped by autozone for them to read the codes for free, got a P000A code.
looked it up online, Intake Camshaft Adjustments
http://www.renntech.org/forums/topic...-s-p000a-code/
hopefully, it's nothing big but i have my warranty paperwork in hand.
called the dealer, will be there at 8am for them to take a look at. stopped by autozone for them to read the codes for free, got a P000A code.
looked it up online, Intake Camshaft Adjustments
http://www.renntech.org/forums/topic...-s-p000a-code/
hopefully, it's nothing big but i have my warranty paperwork in hand.
#215
09-28-2016, 05:36 PM
Registered User
I doubt very much if it's this problem.. by 2012 it appears Porsche had gone back to the steel bolts.
#217
09-28-2016, 10:45 PM
Registered User
The real clue if you have aluminum ones is - does the torx recess have a pin sticking up in the center (commonly "anti-tamper" design, requiring a special torx driver)?
If so - it's aluminum. Porsche made ALL the aluminum bolts on the car with the anti-tamper torx so the mechanics would know they are not to be reused - they are always to be replaced (they are typically angle torqued - ie - stretched on installation.)
If not - and it's a plain allen recess (or plain torx recess) - chances are it's steel.
I'm surprised that a 2012 would still have the aluminum bolts - but I guess it must depend on the production date of your engine. You can usually find the build date of the vehicle by using the VIN decoders that are available on-line.
If so - it's aluminum. Porsche made ALL the aluminum bolts on the car with the anti-tamper torx so the mechanics would know they are not to be reused - they are always to be replaced (they are typically angle torqued - ie - stretched on installation.)
If not - and it's a plain allen recess (or plain torx recess) - chances are it's steel.
I'm surprised that a 2012 would still have the aluminum bolts - but I guess it must depend on the production date of your engine. You can usually find the build date of the vehicle by using the VIN decoders that are available on-line.
#218
10-01-2016, 04:20 PM
Registered User
OK. It's the weekend, and I can report mine were replaced. Here is the rest of the story.
It took a tad longer than it normally would. The dealer had estimated 1 day turnaround. That turns out should have been 1 month.
They had all the parts, and they thought the job was complete, but unfortunately - the mechanic somehow had mistimed one camshaft. That resulted in 8 bent exhaust valves. Fixing the 8 bent valves involved removing the engine (and suspension and transmission, and.. and.. it drops out as a unit) then removing both heads. The heads were then sent to a specialty Porsche performance shop and both heads were disassembled, cleaned, bent valves replaced and reassembled.
This was a big job. Luckily I wasn't paying the tab - I suspect it exceeded $10k (with $2k worth of parts, 2 mechanics for about 4 days, and the performance shop charges, plus I had their Cayenne diesel loaner for a month, and the Turbo clogged up one of their service bays for the best part of the month.)
Got it back yesterday. There is an upside to this - it got a new serpentine belt (their gift to me) and a new water pump (wasn't bad - but since the engine was out it would never be easier - and the old one had 63,000 miles on it) at my cost for the part. It also got the intakes cleaned, and the piston tops cleaned up.
The intakes are a real problem with direct injection engines. Since there is no fuel being sprayed on the valves carbon deposits will build up, eventually bad enough to really start effecting performance. Mine had deposits. Weren't awful, but idle was never totally smooth (common symptom for this.. plus loss of performance.) Cleaning them isn't simple. No magic spray in a can. There are some soak techniques used, but most manufacturers are adopting the old BMW walnut-blast cleaning process. On a Cayenne V8 that's not awful since the intakes are pretty accessible on top of the engine by removing the intake, which isn't an awful thing to do. But - you've got to have the machine, and do each intake, then rotate the engine to close another set of valves, then reassemble - I'm betting at least 1 days labor for the job. Some shops simply scrape them clean (less satisfactory IMHO..)
My heads came back spotless. I purposely asked to see them when they returned before being put on the engine - and I was impressed. VERY nice job by the specialty shop.
Now it idles perfectly. That's an improvement. And it has VarioCam adjusters that I don't have to worry about exploding. I have the old ones and will explore R&R of the aluminum bolts with steel ones. The new ones do use Torx bolts - but without the anti-tamper pin in the center of the Torx recess (Porsche uses this to indicate one time use aluminum bolts) as I theorized above. SO - it's real easy to tell if you have the aluminum bolts - has a pin in the center of the Torx - it's aluminum. No pin - it's steel.
Theoretically - and we need someone to try this - it should be possible to replace the bolts one at a time without removing the VarioCam adjusters, by removing the valve covers. R&R of the covers isn't a lot more work if you're doing a job like sparkplugs. You'll need to be VERY careful not to drop one of the bolts down into the engine, but there should be absolutely no need to re-time the cams since they're never disconnected from the adjusters.
Overall - this would be a much less daunting DIY job.. or at least a job for a good skilled independent mechanic. And a bunch less in parts.
It took a tad longer than it normally would. The dealer had estimated 1 day turnaround. That turns out should have been 1 month.
They had all the parts, and they thought the job was complete, but unfortunately - the mechanic somehow had mistimed one camshaft. That resulted in 8 bent exhaust valves. Fixing the 8 bent valves involved removing the engine (and suspension and transmission, and.. and.. it drops out as a unit) then removing both heads. The heads were then sent to a specialty Porsche performance shop and both heads were disassembled, cleaned, bent valves replaced and reassembled.
This was a big job. Luckily I wasn't paying the tab - I suspect it exceeded $10k (with $2k worth of parts, 2 mechanics for about 4 days, and the performance shop charges, plus I had their Cayenne diesel loaner for a month, and the Turbo clogged up one of their service bays for the best part of the month.)
Got it back yesterday. There is an upside to this - it got a new serpentine belt (their gift to me) and a new water pump (wasn't bad - but since the engine was out it would never be easier - and the old one had 63,000 miles on it) at my cost for the part. It also got the intakes cleaned, and the piston tops cleaned up.
The intakes are a real problem with direct injection engines. Since there is no fuel being sprayed on the valves carbon deposits will build up, eventually bad enough to really start effecting performance. Mine had deposits. Weren't awful, but idle was never totally smooth (common symptom for this.. plus loss of performance.) Cleaning them isn't simple. No magic spray in a can. There are some soak techniques used, but most manufacturers are adopting the old BMW walnut-blast cleaning process. On a Cayenne V8 that's not awful since the intakes are pretty accessible on top of the engine by removing the intake, which isn't an awful thing to do. But - you've got to have the machine, and do each intake, then rotate the engine to close another set of valves, then reassemble - I'm betting at least 1 days labor for the job. Some shops simply scrape them clean (less satisfactory IMHO..)
My heads came back spotless. I purposely asked to see them when they returned before being put on the engine - and I was impressed. VERY nice job by the specialty shop.
Now it idles perfectly. That's an improvement. And it has VarioCam adjusters that I don't have to worry about exploding. I have the old ones and will explore R&R of the aluminum bolts with steel ones. The new ones do use Torx bolts - but without the anti-tamper pin in the center of the Torx recess (Porsche uses this to indicate one time use aluminum bolts) as I theorized above. SO - it's real easy to tell if you have the aluminum bolts - has a pin in the center of the Torx - it's aluminum. No pin - it's steel.
Theoretically - and we need someone to try this - it should be possible to replace the bolts one at a time without removing the VarioCam adjusters, by removing the valve covers. R&R of the covers isn't a lot more work if you're doing a job like sparkplugs. You'll need to be VERY careful not to drop one of the bolts down into the engine, but there should be absolutely no need to re-time the cams since they're never disconnected from the adjusters.
Overall - this would be a much less daunting DIY job.. or at least a job for a good skilled independent mechanic. And a bunch less in parts.
#219
10-01-2016, 07:45 PM
you only had to pay for the bolts right? porsche covered the mess up in the install?
the check engine light was thrown from a senor, but the sensor tested good so they reset the light. i might have them do the bolts if i end up having to replace the sensor (i think they have to take off the valve cover anyways).
the check engine light was thrown from a senor, but the sensor tested good so they reset the light. i might have them do the bolts if i end up having to replace the sensor (i think they have to take off the valve cover anyways).
OK. It's the weekend, and I can report mine were replaced. Here is the rest of the story.
It took a tad longer than it normally would. The dealer had estimated 1 day turnaround. That turns out should have been 1 month.
They had all the parts, and they thought the job was complete, but unfortunately - the mechanic somehow had mistimed one camshaft. That resulted in 8 bent exhaust valves. Fixing the 8 bent valves involved removing the engine (and suspension and transmission, and.. and.. it drops out as a unit) then removing both heads. The heads were then sent to a specialty Porsche performance shop and both heads were disassembled, cleaned, bent valves replaced and reassembled.
This was a big job. Luckily I wasn't paying the tab - I suspect it exceeded $10k (with $2k worth of parts, 2 mechanics for about 4 days, and the performance shop charges, plus I had their Cayenne diesel loaner for a month, and the Turbo clogged up one of their service bays for the best part of the month.)
Got it back yesterday. There is an upside to this - it got a new serpentine belt (their gift to me) and a new water pump (wasn't bad - but since the engine was out it would never be easier - and the old one had 63,000 miles on it) at my cost for the part. It also got the intakes cleaned, and the piston tops cleaned up.
The intakes are a real problem with direct injection engines. Since there is no fuel being sprayed on the valves carbon deposits will build up, eventually bad enough to really start effecting performance. Mine had deposits. Weren't awful, but idle was never totally smooth (common symptom for this.. plus loss of performance.) Cleaning them isn't simple. No magic spray in a can. There are some soak techniques used, but most manufacturers are adopting the old BMW walnut-blast cleaning process. On a Cayenne V8 that's not awful since the intakes are pretty accessible on top of the engine by removing the intake, which isn't an awful thing to do. But - you've got to have the machine, and do each intake, then rotate the engine to close another set of valves, then reassemble - I'm betting at least 1 days labor for the job. Some shops simply scrape them clean (less satisfactory IMHO..)
My heads came back spotless. I purposely asked to see them when they returned before being put on the engine - and I was impressed. VERY nice job by the specialty shop.
Now it idles perfectly. That's an improvement. And it has VarioCam adjusters that I don't have to worry about exploding. I have the old ones and will explore R&R of the aluminum bolts with steel ones. The new ones do use Torx bolts - but without the anti-tamper pin in the center of the Torx recess (Porsche uses this to indicate one time use aluminum bolts) as I theorized above. SO - it's real easy to tell if you have the aluminum bolts - has a pin in the center of the Torx - it's aluminum. No pin - it's steel.
Theoretically - and we need someone to try this - it should be possible to replace the bolts one at a time without removing the VarioCam adjusters, by removing the valve covers. R&R of the covers isn't a lot more work if you're doing a job like sparkplugs. You'll need to be VERY careful not to drop one of the bolts down into the engine, but there should be absolutely no need to re-time the cams since they're never disconnected from the adjusters.
Overall - this would be a much less daunting DIY job.. or at least a job for a good skilled independent mechanic. And a bunch less in parts.
It took a tad longer than it normally would. The dealer had estimated 1 day turnaround. That turns out should have been 1 month.
They had all the parts, and they thought the job was complete, but unfortunately - the mechanic somehow had mistimed one camshaft. That resulted in 8 bent exhaust valves. Fixing the 8 bent valves involved removing the engine (and suspension and transmission, and.. and.. it drops out as a unit) then removing both heads. The heads were then sent to a specialty Porsche performance shop and both heads were disassembled, cleaned, bent valves replaced and reassembled.
This was a big job. Luckily I wasn't paying the tab - I suspect it exceeded $10k (with $2k worth of parts, 2 mechanics for about 4 days, and the performance shop charges, plus I had their Cayenne diesel loaner for a month, and the Turbo clogged up one of their service bays for the best part of the month.)
Got it back yesterday. There is an upside to this - it got a new serpentine belt (their gift to me) and a new water pump (wasn't bad - but since the engine was out it would never be easier - and the old one had 63,000 miles on it) at my cost for the part. It also got the intakes cleaned, and the piston tops cleaned up.
The intakes are a real problem with direct injection engines. Since there is no fuel being sprayed on the valves carbon deposits will build up, eventually bad enough to really start effecting performance. Mine had deposits. Weren't awful, but idle was never totally smooth (common symptom for this.. plus loss of performance.) Cleaning them isn't simple. No magic spray in a can. There are some soak techniques used, but most manufacturers are adopting the old BMW walnut-blast cleaning process. On a Cayenne V8 that's not awful since the intakes are pretty accessible on top of the engine by removing the intake, which isn't an awful thing to do. But - you've got to have the machine, and do each intake, then rotate the engine to close another set of valves, then reassemble - I'm betting at least 1 days labor for the job. Some shops simply scrape them clean (less satisfactory IMHO..)
My heads came back spotless. I purposely asked to see them when they returned before being put on the engine - and I was impressed. VERY nice job by the specialty shop.
Now it idles perfectly. That's an improvement. And it has VarioCam adjusters that I don't have to worry about exploding. I have the old ones and will explore R&R of the aluminum bolts with steel ones. The new ones do use Torx bolts - but without the anti-tamper pin in the center of the Torx recess (Porsche uses this to indicate one time use aluminum bolts) as I theorized above. SO - it's real easy to tell if you have the aluminum bolts - has a pin in the center of the Torx - it's aluminum. No pin - it's steel.
Theoretically - and we need someone to try this - it should be possible to replace the bolts one at a time without removing the VarioCam adjusters, by removing the valve covers. R&R of the covers isn't a lot more work if you're doing a job like sparkplugs. You'll need to be VERY careful not to drop one of the bolts down into the engine, but there should be absolutely no need to re-time the cams since they're never disconnected from the adjusters.
Overall - this would be a much less daunting DIY job.. or at least a job for a good skilled independent mechanic. And a bunch less in parts.
#220
10-02-2016, 12:11 AM
Registered User
I also paid for the new water pump I had them install while the engine was out.
They paid for the rest.. which I suspect was probably close to $10k or so.
There is no replacement yet for the bolts.. but I intend to remove a bolt from one of my old VarioCam adjusters and see what size steel bolt could be used to replace it. If you look at the design, it would be MUCH simpler to just replace the bolts one at a time (so nothing has to come apart or be timed) with the VarioCam adjusters still in place on the engine. So far I see no reason this couldn't be done..
#221
10-06-2016, 07:51 PM
Also, I may have missed your explanation, but why did you decide to spend $2500-ish to have the dealer make the swap rather than follow through with your independent Porsche mechanic to replace only the bolts?
I hope you find the time to remove one of the aluminum bolts and pop into a Fastenal store or similar to determine if a suitable steel bolt replacement can be had. If I knew what size/configuration bolt to purchase, I'd have my indy just replace the bolts.
Glad your ordeal is over; congrats on your newfound peace of mind.
#222
10-06-2016, 11:21 PM
Registered User
When you scheduled the job, did the SA or Service Manager try to dissuade you? We all know the company policy is deny that any such problem exists; I'm just wondering if that extends to this scenario or if the service department suddenly changed their tune when you made it clear you were paying for the job out-of-pocket.
Thanks.
#223
10-07-2016, 05:06 PM
I never considered that an OEM might use a threadlocker. I've never heard of such, but I'm far from an expert. It would help explain why Porsche replaces the entire assembly rather than just the bolts on campaigned cars. I look forward to hearing what you discover.
#224
10-07-2016, 05:28 PM
Registered User
I never considered that an OEM might use a threadlocker. I've never heard of such, but I'm far from an expert. It would help explain why Porsche replaces the entire assembly rather than just the bolts on campaigned cars. I look forward to hearing what you discover.
So it won't surprise me to find it has threadlocker on it. Gotta get to that real soon now.
Step #1 - see if I have an anti-tamper Torx that size..