2006 997 C4S Surging Problem
07-11-2018, 02:28 PM
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2006 997 C4S Surging Problem
Yesterday evening after 55,000 miles of trouble free usage, my 2006 997.1 C4S started lurching, or lunging when under acceleration or under throttle. It started off slowly and very slight, but within 15 miles it was starting to get more violent. The engine RPM’s were not lunging, and the motor seems to stay calm, but the car was jerking in acceleration. When the accelerator was let off there was no more jerking. Does anyone have any idea what this may be, and has anyone experienced this?
No codes. My wife thought I was tapping on the accelerator and doing it for fun. Took it to my mechanic this morning that specializes in all exotic cars. We drove it around, and couldn’t get it to replicate. He said clutch felt fine, and should have plenty of life left. He gave me some special injector cleaner and I have topped off the fuel. Going to drive it around today to flush system or get it to replicate. Maybe I got bad fuel? Don’t know, but very frustrating because you know something is lurking.
No codes. My wife thought I was tapping on the accelerator and doing it for fun. Took it to my mechanic this morning that specializes in all exotic cars. We drove it around, and couldn’t get it to replicate. He said clutch felt fine, and should have plenty of life left. He gave me some special injector cleaner and I have topped off the fuel. Going to drive it around today to flush system or get it to replicate. Maybe I got bad fuel? Don’t know, but very frustrating because you know something is lurking.
07-12-2018, 09:02 AM
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Next time it does it, hit the Eco button on your HVAC controller and make sure recirculate isn't activated. This will eliminate the A/C compressor as a possible cause. When were plugs and coil packs last done? Was it raining or wet when this took place, then dry out when you took it to the mechanic?
07-12-2018, 10:40 AM
#3
Next time it does it, hit the Eco button on your HVAC controller and make sure recirculate isn't activated. This will eliminate the A/C compressor as a possible cause. When were plugs and coil packs last done? Was it raining or wet when this took place, then dry out when you took it to the mechanic?
07-12-2018, 11:17 AM
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Next time it does it, hit the Eco button on your HVAC controller and make sure recirculate isn't activated. This will eliminate the A/C compressor as a possible cause. When were plugs and coil packs last done? Was it raining or wet when this took place, then dry out when you took it to the mechanic?
07-12-2018, 11:19 AM
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07-12-2018, 11:34 AM
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9 times out of 10, wet weather runnability issues are usually cracked coil packs where the water is shorting them out. You can inspect them just by being under the car and looking at the insulators on the visible side. I bet this is your problem. Get the revised thicker insulator ones as they last longer - Genuine Porsche or OEM (Bosch or Beru) only. The new ones with thicker insulators require slightly longer bolts but those are usually included in the box.
A/C compressor can sometimes cause surging as the clutches engage and disengage when maintaining a temperature in Auto mode.
A/C compressor can sometimes cause surging as the clutches engage and disengage when maintaining a temperature in Auto mode.
07-12-2018, 01:36 PM
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9 times out of 10, wet weather runnability issues are usually cracked coil packs where the water is shorting them out. You can inspect them just by being under the car and looking at the insulators on the visible side. I bet this is your problem. Get the revised thicker insulator ones as they last longer - Genuine Porsche or OEM (Bosch or Beru) only. The new ones with thicker insulators require slightly longer bolts but those are usually included in the box.
A/C compressor can sometimes cause surging as the clutches engage and disengage when maintaining a temperature in Auto mode.
A/C compressor can sometimes cause surging as the clutches engage and disengage when maintaining a temperature in Auto mode.
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09-10-2018, 05:02 PM
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It has happened to me in the past when I go thru the drive thru car wash w/ my rear deck lid spoiler up. It stops after driving just a small distance.
09-10-2018, 05:24 PM
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It must have had to have been driving in extremely wet conditions for a while, because after it dried up the problem disappeared. It could have been bad fuel as well from a shady gas station. I did put some German brand fuel injector cleaner in it as well. Someone on another site said it’s the ignition couls cracking and getting wet, and to replace the ignition coils which I haven’t done yet. I haven’t had thenproblem since the it dried up.
09-10-2018, 05:32 PM
#11
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Ignition firing problems will most likely throw a code and dash light... it did this when my coils went on my Boxster. My vote is the A/C or something other bearing/wheel on the serpentine belts.
Peace
Bruce in Philly
Peace
Bruce in Philly
Last edited by Bruce In Philly; 09-10-2018 at 07:40 PM.
09-12-2018, 02:57 AM
#12
I have had similar symptons 3 or 4 times over the years. "Bucking Bronco" is how i would describe it. scared the daylights out of me first time it happened. thought engine was seriously damaged. For me it was bad fuel. a quart of chevron techron fuel system cleaner along with a full tank of chevron supreme fixes the problem for me every time. May take a 1/4 tank to take affect. Although i must say I do not drive in wet weather very much, so your problem may be different. but I would try the fuel system cleaner first to rule that out. keep us posted.
09-12-2018, 08:57 AM
#13
FWIW, same model, year, and symptoms. Indy says coils are good when I had plugs changed (55k). Still have the problem intermittently but almost always when wet. I did throw a code for rich idle once...not sure if that’s related but I intend to start preemptively addressing any possible culprits as this is my DD.
09-12-2018, 09:52 AM
#14
Drifting
It has happened to me maybe 4 times in the last couple of years.
Its not something that happens regularly but it has happened 2x in the past week although it didnt happened yesterday when i was out for 200km drive
Bruce, i have seen your notes in the past re the A/C so will see if thats whats happening next time it comes up - thanks
Here is the list of possible causes i have seen mentioned:
I will have it at my indy in a while and will have it on the scanner so will see if he comes up with anything
Cheers
- not related to being wet as it was clear at least in the past 2 instances and had not rained for days before hand
- the A/C was running the most recent time but cant recall if it was when it happened the week before - i rarely run the A/C in the summer but had some heat on the other day when it happened
- it can be quiet violent when you get on the throttle and is still apparent under constant throttle; dont notice it at idle
- in all instances it lasts 5-10 mins and then disappears; turning the engine on/off doesnt solve the problem
- no codes were thrown
- as i have been breaking in the engine, i have been running lots of (good) gas through it so doubt that is the issue
- also doubt it is the coils as they are relatively new and when i had misfires with coils it always throws a code
Its not something that happens regularly but it has happened 2x in the past week although it didnt happened yesterday when i was out for 200km drive
Bruce, i have seen your notes in the past re the A/C so will see if thats whats happening next time it comes up - thanks
Here is the list of possible causes i have seen mentioned:
- bad coils/plugs
- bad or dirty throttle body
- A/C compressor going
- loose connection to fuel pump
- faulty high pressure fuel pump
- vacuum leak
- throttle position sensor
- cam position sensor
- dirty/faulty MAF
I will have it at my indy in a while and will have it on the scanner so will see if he comes up with anything
Cheers
09-12-2018, 10:19 AM
#15
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It has happened to me maybe 4 times in the last couple of years.
Its not something that happens regularly but it has happened 2x in the past week although it didnt happened yesterday when i was out for 200km drive
Bruce, i have seen your notes in the past re the A/C so will see if thats whats happening next time it comes up - thanks
Here is the list of possible causes i have seen mentioned:
I will have it at my indy in a while and will have it on the scanner so will see if he comes up with anything
Cheers
- not related to being wet as it was clear at least in the past 2 instances and had not rained for days before hand
- the A/C was running the most recent time but cant recall if it was when it happened the week before - i rarely run the A/C in the summer but had some heat on the other day when it happened
- it can be quiet violent when you get on the throttle and is still apparent under constant throttle; dont notice it at idle
- in all instances it lasts 5-10 mins and then disappears; turning the engine on/off doesnt solve the problem
- no codes were thrown
- as i have been breaking in the engine, i have been running lots of (good) gas through it so doubt that is the issue
- also doubt it is the coils as they are relatively new and when i had misfires with coils it always throws a code
Its not something that happens regularly but it has happened 2x in the past week although it didnt happened yesterday when i was out for 200km drive
Bruce, i have seen your notes in the past re the A/C so will see if thats whats happening next time it comes up - thanks
Here is the list of possible causes i have seen mentioned:
- bad coils/plugs
- bad or dirty throttle body
- A/C compressor going
- loose connection to fuel pump
- faulty high pressure fuel pump
- vacuum leak
- throttle position sensor
- cam position sensor
- dirty/faulty MAF
I will have it at my indy in a while and will have it on the scanner so will see if he comes up with anything
Cheers
- bad coils/plugs - if it happens when its wet, cooks are the likely cause
- bad or dirty throttle body - maybe
- A/C compressor going - could just be the compressor cycling and creating drag on the motor, then disengaging. I can feel when my compressor engages and disengages when I have it on. I usually drive the car in Eco mode to disable the A/C unless its 90 or above out. It just runs better.
- loose connection to fuel pump - unlikely
- faulty high pressure fuel pump - Only the DFI cars (2009 and newer) have the HPFP. Our .1s have just the regular pump. Unlikely this is your issue
- vacuum leak - maybe
- throttle position sensor - maybe. If you can get it yo do it reliably, you can track live values with Durametric on the pedal position sensor and the throttle body position sensor to see if one is fluctuating while the other remains steady.
- cam position sensor - unlikely. This would cause misfires on all 3 cylinders on one bank of the engine and would cause a CEL
- dirty/faulty MAF - maybe. Unplugging it will put the car into limp mode and stop metering air and making adjustments. If it doesn't do it with the MAF disconnected, that's it.