Miss Piggy is having a bad day
02-08-2019, 05:09 AM
#1
Miss Piggy is having a bad day
Cayenne S 2004
Driving home from work yesterday everything was fine on highway but once in slower traffic the car started juddering / shaking / lurching. Had to drop down a gear to keep the car moving last few KM home.
Low power and shaking at low revs and a an intermittent gurgling popping sound from one side of the exhaust at idle. Sounds like a Harley.
No CEL
My my first guess is a dead coil, I have removed coil plugs one at a time and the idle gets rougher except when I disconnected one of the coil plugs.
Before i I go crazy looking into this further can anybody confirm that this could be caused by a dead coil?
Driving home from work yesterday everything was fine on highway but once in slower traffic the car started juddering / shaking / lurching. Had to drop down a gear to keep the car moving last few KM home.
Low power and shaking at low revs and a an intermittent gurgling popping sound from one side of the exhaust at idle. Sounds like a Harley.
No CEL
My my first guess is a dead coil, I have removed coil plugs one at a time and the idle gets rougher except when I disconnected one of the coil plugs.
Before i I go crazy looking into this further can anybody confirm that this could be caused by a dead coil?
02-08-2019, 10:16 AM
#3
Three Wheelin'
Sounds like a coil pack to me also .
02-08-2019, 02:00 PM
#4
Banned
Join Date: Mar 2011
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"Could be" - but troubleshooting by parts replacement can get expensive. Could also be a plug, could be a fuel pump, could be crap gasoline - lots of stuff "could be" wrong with Miss Piggy.
How to find what it "probably is" - diagnostics. Strangely misfires on Cayennes don't normally trip the CEL. Dunno why. Ditto on fuel pumps usually. You need a Porsche specific diagnostics tool if you're considering DIY. If not - then it's take it to wherever you usually take it and start handing over cash..
How to find what it "probably is" - diagnostics. Strangely misfires on Cayennes don't normally trip the CEL. Dunno why. Ditto on fuel pumps usually. You need a Porsche specific diagnostics tool if you're considering DIY. If not - then it's take it to wherever you usually take it and start handing over cash..
02-08-2019, 02:07 PM
#5
"Could be" - but troubleshooting by parts replacement can get expensive. Could also be a plug, could be a fuel pump, could be crap gasoline - lots of stuff "could be" wrong with Miss Piggy.
How to find what it "probably is" - diagnostics. Strangely misfires on Cayennes don't normally trip the CEL. Dunno why. Ditto on fuel pumps usually. You need a Porsche specific diagnostics tool if you're considering DIY. If not - then it's take it to wherever you usually take it and start handing over cash..
How to find what it "probably is" - diagnostics. Strangely misfires on Cayennes don't normally trip the CEL. Dunno why. Ditto on fuel pumps usually. You need a Porsche specific diagnostics tool if you're considering DIY. If not - then it's take it to wherever you usually take it and start handing over cash..
Im using OBDeleven with a modified adapter and have been happy so far.
In in this case I’m going to throw in one new coil (when I can find one here in Finalnd) and see where that takes me. Plugs were recently replaced (2000km ago) and all look good again now. The second from front driver side coil did not make any difference to idle when unplugged but all of the others did. So my manual diagnostics lead me that way.
The other option of course is the good old scoring monster although if it is I think I would hold the record at 240tkms
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02-11-2019, 09:46 AM
#10
Rennlist Member
Same symptoms on my '05. It was coils.
03-17-2019, 01:36 PM
#11
Sorry for the radio silence.
Had 3 cracked coils. Changed coils and plugs. Misfire gone.
Still trying to track down source of knocking sound.
Almost no oil consumption. No codes. No shaking.
But it sounds like a cold diesel until about 2300 RPM
Scoped cylinders all looking good.
Will perform comp test next.
Had 3 cracked coils. Changed coils and plugs. Misfire gone.
Still trying to track down source of knocking sound.
Almost no oil consumption. No codes. No shaking.
But it sounds like a cold diesel until about 2300 RPM
Scoped cylinders all looking good.
Will perform comp test next.
03-17-2019, 08:34 PM
#12
Instructor
I finally bought a set from Porsche.
I went through two sets of cheapie coils purchased on Amazon.ca before I saw the light and paid for a set from the Porsche dealer. That cleared up the problem immediately.
The problem is that a misfiring coil usually doesn't misbehave badly enough to pop a CEL code, and until it does, there is no way to tell which is defective.
I have documented my game of whack-a-mole with the cheap coils on
https://rodcroskery.wordpress.com/20...-just-changed/
The articles are in reverse chronological order. October 13, 2018 is the most relevant to this discussion, and you may follow the link to its follow-up in November, 2018.
I hope this helps,
Rod Croskery
Portland, Ontario, Canada
The problem is that a misfiring coil usually doesn't misbehave badly enough to pop a CEL code, and until it does, there is no way to tell which is defective.
I have documented my game of whack-a-mole with the cheap coils on
https://rodcroskery.wordpress.com/20...-just-changed/
The articles are in reverse chronological order. October 13, 2018 is the most relevant to this discussion, and you may follow the link to its follow-up in November, 2018.
I hope this helps,
Rod Croskery
Portland, Ontario, Canada
03-17-2019, 09:56 PM
#13
Rennlist Member
Coil issues can definitely be maddening. I lived with an intermittent, load-related stutter for a couple years before changing all the coils (which were cracked) and having the issue go away.
I now believe that Durametric and iCarScan x431 tools will help you diagnose the issue and/or pinpoint which cylinder/coil(s) is misbehaving. What you want to do is log misfires or check the rough running index for each cylinder. For the misfire count, closer to zero is obviously better. On a short drive a couple misfires per cylinder is no big deal, but if you're seeing many more on one cylinder, there's your problem. Same applies to the rough running index, though it's not a count of misfires so much as a measurement of deviations in power amongst the cylinders. In my experience, the numbers usually bounce around +/-.0.5 or less. If one of the cylinders is way out of line, there's an issue. Note that both of these tests can help identify a problematic cylinder, but won't definitively confirm a coil - - there could be other issues (plugs, compression, etc.). You can swap coils on two cylinders (good and bad) and re-test to see if the problem cylinder moved with the suspect coil.
As a practical matter, if you've got one bad coil, the others are likely on borrowed time. The Beru units are cheap enough that it's probably worth your while to swap them all and put in fresh plugs while you are at it.
I now believe that Durametric and iCarScan x431 tools will help you diagnose the issue and/or pinpoint which cylinder/coil(s) is misbehaving. What you want to do is log misfires or check the rough running index for each cylinder. For the misfire count, closer to zero is obviously better. On a short drive a couple misfires per cylinder is no big deal, but if you're seeing many more on one cylinder, there's your problem. Same applies to the rough running index, though it's not a count of misfires so much as a measurement of deviations in power amongst the cylinders. In my experience, the numbers usually bounce around +/-.0.5 or less. If one of the cylinders is way out of line, there's an issue. Note that both of these tests can help identify a problematic cylinder, but won't definitively confirm a coil - - there could be other issues (plugs, compression, etc.). You can swap coils on two cylinders (good and bad) and re-test to see if the problem cylinder moved with the suspect coil.
As a practical matter, if you've got one bad coil, the others are likely on borrowed time. The Beru units are cheap enough that it's probably worth your while to swap them all and put in fresh plugs while you are at it.
03-18-2019, 12:10 PM
#14
Silly question on OBE part numbers... The coils FS as listed from multiple vendors still follow the old PN of 948-602-104-14-OEM
When ordering a 948-602-104-14 will you in fact receive the updated 948-602-104-22 ?
JIC as to not order the old item.
When ordering a 948-602-104-14 will you in fact receive the updated 948-602-104-22 ?
JIC as to not order the old item.
03-19-2019, 12:00 AM
#15
Rennlist Member
The Berus have a green sticker and don't list the revision like the more expensive Porsche parts.
When I ordered mine around Christmas, 5150 Motorsports had the best price on new Berus (not Porsche labeled).
Another, slightly more expensive option is to order the Berus from FCP Euro - - all the parts they sell come with a lifetime replacement guarantee. Depending on how long you think you will own your Cayenne, that could be a good deal. I seem to recall the price difference being an extra 50 bucks or so (for all eight, no each).
When I ordered mine around Christmas, 5150 Motorsports had the best price on new Berus (not Porsche labeled).
Another, slightly more expensive option is to order the Berus from FCP Euro - - all the parts they sell come with a lifetime replacement guarantee. Depending on how long you think you will own your Cayenne, that could be a good deal. I seem to recall the price difference being an extra 50 bucks or so (for all eight, no each).
Last edited by Brainz; 03-19-2019 at 05:16 PM.