Discussion
Hi Guys
Just stepped over from my usual home on the HSV forum to pick your brains on my wife's 911 problem.
One Month ago a tappety "ticking" noise devloped from the engine. An independent specialist advised that often this was the result of filaing spark plugs that were often not replaced due to access problems.
2 weeks later check engine light came on. Car no longer used, except to drive to a workshop. On the way the engine failed.
Diagnosed cam sensor, which was replaced to no effect.
Engine does not run. Porsche inserted a camera and found oil in the (or some of the) pistons. They have diagnosed a timing problem,jumped chain possibly.
I have a couple of questions:
How can the timing chain jump on a regularly serviced, 50k mile, never tracked car?
Porsche suggets a replacement engine.
Others suggest a rebuild.
What do you guys think?
BTw, 97C4S 6 years old 50k miles.
Just stepped over from my usual home on the HSV forum to pick your brains on my wife's 911 problem.
One Month ago a tappety "ticking" noise devloped from the engine. An independent specialist advised that often this was the result of filaing spark plugs that were often not replaced due to access problems.
2 weeks later check engine light came on. Car no longer used, except to drive to a workshop. On the way the engine failed.
Diagnosed cam sensor, which was replaced to no effect.
Engine does not run. Porsche inserted a camera and found oil in the (or some of the) pistons. They have diagnosed a timing problem,jumped chain possibly.
I have a couple of questions:
How can the timing chain jump on a regularly serviced, 50k mile, never tracked car?
Porsche suggets a replacement engine.
Others suggest a rebuild.
What do you guys think?
BTw, 97C4S 6 years old 50k miles.
Hang on, you were advised you had a spark plug failing but carried on using the car? And also that this was due to inadequate servicing - did this not raise an alarm bell?
That aside, whilst plugs can fail (I saw a car being routine serviced at Hartech recently and one of the electrodes was missing entirely from the plug tip - a new plug isn't a problem, it's wondering where the old electrode went!), anything that causes a loud ticking is usually something worse than a plug issue.
Anyway, you say you took it to an independent but have now taken it to the OPC? I presume you don't have a warranty then? Definitely worth getting the car transported to someone like Hartech, Autofarm, Sports & Classic - i.e. those who have specific experience of diagnosing problems on and re-building these engines. I think the list price with Porsche for a new engine is now around £12k+VAT+fitting (although it does come with all new ancillaries), whereas a thorough rebuild is likely to be half that at most and include various upgrades to rectify the inherent design flaws of the engine.
That aside, whilst plugs can fail (I saw a car being routine serviced at Hartech recently and one of the electrodes was missing entirely from the plug tip - a new plug isn't a problem, it's wondering where the old electrode went!), anything that causes a loud ticking is usually something worse than a plug issue.
Anyway, you say you took it to an independent but have now taken it to the OPC? I presume you don't have a warranty then? Definitely worth getting the car transported to someone like Hartech, Autofarm, Sports & Classic - i.e. those who have specific experience of diagnosing problems on and re-building these engines. I think the list price with Porsche for a new engine is now around £12k+VAT+fitting (although it does come with all new ancillaries), whereas a thorough rebuild is likely to be half that at most and include various upgrades to rectify the inherent design flaws of the engine.
thegoose said:
Hang on, you were advised you had a spark plug failing but carried on using the car? And also that this was due to inadequate servicing - did this not raise an alarm bell?
That aside, whilst plugs can fail (I saw a car being routine serviced at Hartech recently and one of the electrodes was missing entirely from the plug tip - a new plug isn't a problem, it's wondering where the old electrode went!), anything that causes a loud ticking is usually something worse than a plug issue.
Anyway, you say you took it to an independent but have now taken it to the OPC? I presume you don't have a warranty then? Definitely worth getting the car transported to someone like Hartech, Autofarm, Sports & Classic - i.e. those who have specific experience of diagnosing problems on and re-building these engines. I think the list price with Porsche for a new engine is now around £12k+VAT+fitting (although it does come with all new ancillaries), whereas a thorough rebuild is likely to be half that at most and include various upgrades to rectify the inherent design flaws of the engine.
My 3.6 was replaced just over a year ago by OPC and it was closer to £16k, the OP's 997 C4S with a 3.8 will probably on the wrong side of that!That aside, whilst plugs can fail (I saw a car being routine serviced at Hartech recently and one of the electrodes was missing entirely from the plug tip - a new plug isn't a problem, it's wondering where the old electrode went!), anything that causes a loud ticking is usually something worse than a plug issue.
Anyway, you say you took it to an independent but have now taken it to the OPC? I presume you don't have a warranty then? Definitely worth getting the car transported to someone like Hartech, Autofarm, Sports & Classic - i.e. those who have specific experience of diagnosing problems on and re-building these engines. I think the list price with Porsche for a new engine is now around £12k+VAT+fitting (although it does come with all new ancillaries), whereas a thorough rebuild is likely to be half that at most and include various upgrades to rectify the inherent design flaws of the engine.
petop said:
My 3.6 was replaced just over a year ago by OPC and it was closer to £16k, the OP's 997 C4S with a 3.8 will probably on the wrong side of that!
Well £12k+VAT = £14,400, plus labour so I wasn't too far out I'm sure! Enough to convince anyone paying for it themselves to go down the rebuild route surely?thegoose said:
Well £12k+VAT = £14,400, plus labour so I wasn't too far out I'm sure! Enough to convince anyone paying for it themselves to go down the rebuild route surely?
i agree. It wasnt a pop at you but just to prepare the OP when he asks the OPC for a quote on a replacement engine, the then walks out as if the whole world has just crashed in on him. BATHVXR said:
Thanks All
Yes its a shame that the original indy was so relaxed about the noise. Yes we will be paying ourselves, and Hartech was recommmended by another indy that I trust so thanks for the feedback.
So now for the dumb question. How does a dodgy spark plug lead to a blown engine?
Depends upon how dodgy the spark plug is. A malfunctioning spark plug that just causes misfires probably won't blow the engine though this is not a recommendation to ignore a misfire due to any reason, bad plug or something else.Yes its a shame that the original indy was so relaxed about the noise. Yes we will be paying ourselves, and Hartech was recommmended by another indy that I trust so thanks for the feedback.
So now for the dumb question. How does a dodgy spark plug lead to a blown engine?
But a bad plug that comes apart can wreck havoc with the engine as the piston smashes the plug fragment to pieces using the piston and the head combustion chamber surfaces and valves.
In some cases this can result in a cracked head head or even a cracked block (cylinder wall), piston failure, even rod or crank failure if for instance a valve gets jammed open or a valve head comes loose from all the violence in the chamber.
Depending upon the extent of the damage the engine may not be a good rebuild candidate. Your chosen engine rebuilder should advise you regarding the viability of using the original and "blown" engine for a rebuild.
BATHVXR said:
.
So now for the dumb question. How does a dodgy spark plug lead to a blown engine?
Besides Rockster's explanation, which I can't add a lot to, how do you know it definitely had a dodgy spark plug? Unless one or all the plugs were removed to check after it started getting noisy it sounds like just guesswork to me. All should become clearer once the engine's stripped.So now for the dumb question. How does a dodgy spark plug lead to a blown engine?
Try www.gcrcentral.co.uk in Leicestershire. A guy I met at Le Mans this year bought a 986 Boxster S with 180,000 miles, his engine blew in 7 weeks (bearing failure he thinks) and this outfit replaced his engine with a 60,000 miler for £2.2k and replaced his clutch at the same time for £300 on top all with a 1 year warranty!
thegoose said:
Besides Rockster's explanation, which I can't add a lot to, how do you know it definitely had a dodgy spark plug? Unless one or all the plugs were removed to check after it started getting noisy it sounds like just guesswork to me. All should become clearer once the engine's stripped.
That's a good point. Often the diagnosis of what failed in an engine is just a quess. If right often a lucky guess.Even upon a tear down sometimes it is hard to determine what went wrong in what order.
You know, blowing an engine on a 911 is very much like making love to a beautiful woman.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
You're single, aren't you?! 
Perec said:
You know, blowing an engine on a 911 is very much like making love to a beautiful woman.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
Perec said:
You know, blowing an engine on a 911 is very much like making love to a beautiful woman.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
Perec said:
You know, blowing an engine on a 911 is very much like making love to a beautiful woman.
First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
....and then she empties your wallet? First you show her a bit of neglect, then you give her a good thrashing. Once you've had a bang like you've never experienced before you turn her over and find something unpleasant dripping from her exhaust.
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