Got car washed - misfiring and RPM hunting at idle only
10-17-2023, 10:37 PM
#16
Racer
Thread Starter
Went to pull bank 2 coils and plugs today. Got to cyl 6 (I believe that's the one closest to rear) and the damn connector wasn't clipped in. Came right off when I pulled up on the boot. Strange still that the car wasn't missing through the RPM range though, only at idle...
Wonder if the guy's power washer undid the connector ever so slightly? Thinking of how you push directly onto the clip and it sort of pops, the way a pressure washer would've undid it. He was doing the wheels too, so bet he was using the most aggressive attachment/setting (I've only used a p-washer once, don't really know how they work).... They specifically ask if you want the inside of the wheels cleaned out too. That's not getting done without a lot of water pressure (they don't handwash the inside of the wheel, nor do they take the wheel off).
That said, I ordered an AOS, 6 spark plugs (the coils really do look brand new - I replaced them myself 30K ago - would like to save $250 if I can), another used ICV, and a few other misc things this morning.
How difficult is it to do the AOS now that I have both intake plenums off? Bank 1's intake manifold is still on, but have been told you can swap the AOS without removing the manifold..... In total I'm already in for around $315 between parts and tools. Might be nice to just have the AOS and wait until it really fails (I'm really tired between work and this and my hands are sore as h3ll). That, and I'm by myself. I think I can manage with the tools I have but it'll be hairy I'm sure...
Thanks all for the help thus far.
Wonder if the guy's power washer undid the connector ever so slightly? Thinking of how you push directly onto the clip and it sort of pops, the way a pressure washer would've undid it. He was doing the wheels too, so bet he was using the most aggressive attachment/setting (I've only used a p-washer once, don't really know how they work).... They specifically ask if you want the inside of the wheels cleaned out too. That's not getting done without a lot of water pressure (they don't handwash the inside of the wheel, nor do they take the wheel off).
That said, I ordered an AOS, 6 spark plugs (the coils really do look brand new - I replaced them myself 30K ago - would like to save $250 if I can), another used ICV, and a few other misc things this morning.
How difficult is it to do the AOS now that I have both intake plenums off? Bank 1's intake manifold is still on, but have been told you can swap the AOS without removing the manifold..... In total I'm already in for around $315 between parts and tools. Might be nice to just have the AOS and wait until it really fails (I'm really tired between work and this and my hands are sore as h3ll). That, and I'm by myself. I think I can manage with the tools I have but it'll be hairy I'm sure...
Thanks all for the help thus far.
Last edited by hkovalcik; 10-17-2023 at 10:53 PM.
10-18-2023, 09:43 AM
#17
Rennlist Member
I can't imagine power washing wheels. Not a good idea as you are finding out. I use soap and water and a rag to wash them by hand.. Getting the inside may be hard and wheel removal may be required, but it is by far the best way and you can wash the calipers, too.
To reduce the dust from the pads I recommend Hawk street pads. They have several versions and produce virtually zero dust (and good stopping characteristics). I can clean my wheels in a few minutes with a rag and Quick Detailer.
Some people get their wheels ceramic coated. That may be better, but with the Hawk pads, keeping my wheels clean is a simple processes. Next, I need to swap out the OEM pads on my wife's Macan. Dirty bastards!
To reduce the dust from the pads I recommend Hawk street pads. They have several versions and produce virtually zero dust (and good stopping characteristics). I can clean my wheels in a few minutes with a rag and Quick Detailer.
Some people get their wheels ceramic coated. That may be better, but with the Hawk pads, keeping my wheels clean is a simple processes. Next, I need to swap out the OEM pads on my wife's Macan. Dirty bastards!
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damage98MO (10-18-2023)
10-18-2023, 01:50 PM
#18
Racer
Went to pull bank 2 coils and plugs today. Got to cyl 6 (I believe that's the one closest to rear) and the damn connector wasn't clipped in. Came right off when I pulled up on the boot. Strange still that the car wasn't missing through the RPM range though, only at idle...
That said, I ordered an AOS, 6 spark plugs (the coils really do look brand new - I replaced them myself 30K ago - would like to save $250 if I can), another used ICV, and a few other misc things this morning.
How difficult is it to do the AOS now that I have both intake plenums off? Bank 1's intake manifold is still on, but have been told you can swap the AOS without removing the manifold..... In total I'm already in for around $315 between parts and tools. Might be nice to just have the AOS and wait until it really fails (I'm really tired between work and this and my hands are sore as h3ll). That, and I'm by myself. I think I can manage with the tools I have but it'll be hairy I'm sure...
Thanks all for the help thus far.
That said, I ordered an AOS, 6 spark plugs (the coils really do look brand new - I replaced them myself 30K ago - would like to save $250 if I can), another used ICV, and a few other misc things this morning.
How difficult is it to do the AOS now that I have both intake plenums off? Bank 1's intake manifold is still on, but have been told you can swap the AOS without removing the manifold..... In total I'm already in for around $315 between parts and tools. Might be nice to just have the AOS and wait until it really fails (I'm really tired between work and this and my hands are sore as h3ll). That, and I'm by myself. I think I can manage with the tools I have but it'll be hairy I'm sure...
Thanks all for the help thus far.
Trying to fix your problem engine misfire by tearing down the plenums/intake, changing all the plugs and coils, aos, without even a fault code to go by, or at the least a vacuum leak test, or a manometer test on the aos, is counter productive imo.
Would have been nice to just clip back on the coil wire you found lose/disconnected(?) and see if that fixes your problem before tearing apart everything you did.
I'm not a expert Porsche mechanic/tech by any means, I learn a ton here, but am an expert old troubleshooter by profession and an M E. What I''m trying to covey to you is use a logical step by step process of elimination to troubleshoot your problem. Not a gun ho tear it apart and throw parts at it hoping that fixes it without ever knowing what the problem was. Always do 1 thing at a time, then test what you did, as to not confuse the problem or add additional problems unintentionally. like what you're going to do installing a used dismantler icv part with unknown working condition, or even knowing if yours is bad to begin with.
For the cost of your new set of plugs you could have bought a inexpensive amazon manometer to test the aos. it would test the aos quickly and accurately. Then you'd know for sure the condition of the aos. If its good no need to change it. Occasionally others have installed a new aos that were defective from the get go. You should monitor you aos regularly anyhow and a 996 needed tool is a manometer imo.
If I can instill 1 thing on you, its to not troubleshoot by being a parts changer. Use a logical step by step process of elimination. That doesn't mean installing a load of unneeded different parts till your problem is fixed, if it even ever does get fixed like that.
Spend your money on the correct test tools you really need, like a code reader and manometer. Don't have to get the expensive Porsche scanner system. A more generic less expensive tool will do for many/most of the common things you'll need. I've got a $150 Foxwell that works ok for many things although its not the perfect tool for a 996.2. Ya, you could get an expensive Durametric or piwis and have the best, but it will cost ya. There are many other lots less expensive that will work for things like you need now...
Don't take this the wrong way, just some simple advice that imo will help you understand and fix your car the least expensive and quickest way, take it or leave it...
JMO
Last edited by allcool; 10-18-2023 at 01:59 PM.
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Marv (10-18-2023)
10-18-2023, 01:50 PM
#19
Racer
Thread Starter
In regards to AOS:
How far along am I now that I have both intake plenums off? Anyone have success doing it with bank 1 intake manifold still on the car? Took a look at it last night - aside from that little electrical connector next to it (looking underneath car) and the hose with the press-clamp (circle clamp - not sure what to call it), it looks pretty easy. The two 10-mm seem easy to get to, too. Getting the hoses back on may be a pain but idk.
At this point I think I’m going to put the new plugs in on Friday. Re-use the coils and ensure the connectors are clipped. Clean the TB, MAF, ICV and intakes very, very thoroughly. Clean the plenums and boots. Will be spotless.
Then I’m going to change the oil and drive the car hard. Spoke to a nearby tech and he said oil in plenums and manifolds is normal and more than likely indicative of not driving the car hard enough, or not taking it through full heat cycles when first started each day. He has changed AOS’s on these cars before and still sees oil get accumulated in the manifolds, mostly because the owner doesn’t take it from dead cold to operating temp, or they don’t drive it like it should be driven. If it still idles like sh*t I’ll change the AOS.
Will keep ya’ll updated.
How far along am I now that I have both intake plenums off? Anyone have success doing it with bank 1 intake manifold still on the car? Took a look at it last night - aside from that little electrical connector next to it (looking underneath car) and the hose with the press-clamp (circle clamp - not sure what to call it), it looks pretty easy. The two 10-mm seem easy to get to, too. Getting the hoses back on may be a pain but idk.
At this point I think I’m going to put the new plugs in on Friday. Re-use the coils and ensure the connectors are clipped. Clean the TB, MAF, ICV and intakes very, very thoroughly. Clean the plenums and boots. Will be spotless.
Then I’m going to change the oil and drive the car hard. Spoke to a nearby tech and he said oil in plenums and manifolds is normal and more than likely indicative of not driving the car hard enough, or not taking it through full heat cycles when first started each day. He has changed AOS’s on these cars before and still sees oil get accumulated in the manifolds, mostly because the owner doesn’t take it from dead cold to operating temp, or they don’t drive it like it should be driven. If it still idles like sh*t I’ll change the AOS.
Will keep ya’ll updated.
Last edited by hkovalcik; 10-18-2023 at 01:53 PM.
10-18-2023, 01:57 PM
#20
Racer
Thread Starter
You're not going about troubleshooting your problem in the most economical and time efficient way. You actually could introduce more problems to confuse the matter by what you're contemplating doing.
Tearing down the plenums/intake, changing all the plugs and coils without even a fault code to go by, or at the least a vacuum leak test, or a manometer test on the aos, is counter productive imo.
Would have been nice to just clip back on the coil wire you found lose/disconnected(?) and see if that fixes your problem before tearing apart everything you did.
I'm not a expert Porsche mechanic/tech by any means, I learn a ton here, but am an expert troubleshooter by profession and an M E. What I''m trying to covey to you is use a logical step by step process of elimination to troubleshoot your problem. Not a gun ho tear it apart and throw parts at it hoping that fixes it without ever knowing what the problem was. Always do 1 thing at a time, then test what you did, as to not confuse the problem or add additional problems unintentionally. like what you're going to do installing a used dismantler icv part with unknown working condition, or even knowing if yours is bad to begin with.
For the cost of your new set of plugs you could have bought a inexpensive amazon manometer to test the aos. it would test the aos quickly and accurately. Then you'd know for sure the condition of the aos. If its good no need to change it. Occasionally others have installed a new aos that were defective from the get go. You should monitor you aos regularly anyhow and a 996 needed tool is a manometer imo.
If I can instill 1 thing on you, its to not troubleshoot by being a parts changer. Use a logical step by step process of elimination. That doesn't mean installing a load of unneeded different parts till your problem is fixed, if it even ever does get fixed like that.
Spend your money on the correct test tools you really need, like a code reader and manometer. Don't have to get the expensive Porsche scanner system. A more generic less expensive tool will do for many/most of the common things you'll need. I've got a $150 Foxwell that works ok for many things although its not the perfect tool for a 996.2. Ya, you could get an expensive Durametric or piwis and have the best, but it will cost ya. There are many other lots less expensive that will work for things like you need now...
Don't take this the wrong way, just some simple advice that imo will help you understand and fix your car the least expensive and quickest way, take it or leave it...
JMO
Tearing down the plenums/intake, changing all the plugs and coils without even a fault code to go by, or at the least a vacuum leak test, or a manometer test on the aos, is counter productive imo.
Would have been nice to just clip back on the coil wire you found lose/disconnected(?) and see if that fixes your problem before tearing apart everything you did.
I'm not a expert Porsche mechanic/tech by any means, I learn a ton here, but am an expert troubleshooter by profession and an M E. What I''m trying to covey to you is use a logical step by step process of elimination to troubleshoot your problem. Not a gun ho tear it apart and throw parts at it hoping that fixes it without ever knowing what the problem was. Always do 1 thing at a time, then test what you did, as to not confuse the problem or add additional problems unintentionally. like what you're going to do installing a used dismantler icv part with unknown working condition, or even knowing if yours is bad to begin with.
For the cost of your new set of plugs you could have bought a inexpensive amazon manometer to test the aos. it would test the aos quickly and accurately. Then you'd know for sure the condition of the aos. If its good no need to change it. Occasionally others have installed a new aos that were defective from the get go. You should monitor you aos regularly anyhow and a 996 needed tool is a manometer imo.
If I can instill 1 thing on you, its to not troubleshoot by being a parts changer. Use a logical step by step process of elimination. That doesn't mean installing a load of unneeded different parts till your problem is fixed, if it even ever does get fixed like that.
Spend your money on the correct test tools you really need, like a code reader and manometer. Don't have to get the expensive Porsche scanner system. A more generic less expensive tool will do for many/most of the common things you'll need. I've got a $150 Foxwell that works ok for many things although its not the perfect tool for a 996.2. Ya, you could get an expensive Durametric or piwis and have the best, but it will cost ya. There are many other lots less expensive that will work for things like you need now...
Don't take this the wrong way, just some simple advice that imo will help you understand and fix your car the least expensive and quickest way, take it or leave it...
JMO
Edit- and then if AOS is changed and still not running right, will just do the ICV and MAF. That should be the end-all. If not, will change the coils as a last resort.
edit x2- and Yep I did get codes. Misfires on 5 cyls and enrichment limit from two O2s.
Last edited by hkovalcik; 10-18-2023 at 02:01 PM.
10-18-2023, 02:03 PM
#21
Rennlist Member
In regards to AOS:
How far along am I now that I have both intake plenums off? Anyone have success doing it with bank 1 intake manifold still on the car? Took a look at it last night - aside from that little electrical connector next to it (looking underneath car) and the hose with the press-clamp (circle clamp - not sure what to call it), it looks pretty easy. The two 10-mm seem easy to get to, too. Getting the hoses back on may be a pain but idk.
At this point I think I’m going to put the new plugs in on Friday. Re-use the coils and ensure the connectors are clipped. Clean the TB, MAF, ICV and intakes very, very thoroughly. Clean the plenums and boots. Will be spotless.
Then I’m going to change the oil and drive the car hard. Spoke to a nearby tech and he said oil in plenums and manifolds is normal and more than likely indicative of not driving the car hard enough, or not taking it through full heat cycles when first started each day. He has changed AOS’s on these cars before and still sees oil get accumulated in the manifolds, mostly because the owner doesn’t take it from dead cold to operating temp, or they don’t drive it like it should be driven. If it still idles like sh*t I’ll change the AOS.
Will keep ya’ll updated.
How far along am I now that I have both intake plenums off? Anyone have success doing it with bank 1 intake manifold still on the car? Took a look at it last night - aside from that little electrical connector next to it (looking underneath car) and the hose with the press-clamp (circle clamp - not sure what to call it), it looks pretty easy. The two 10-mm seem easy to get to, too. Getting the hoses back on may be a pain but idk.
At this point I think I’m going to put the new plugs in on Friday. Re-use the coils and ensure the connectors are clipped. Clean the TB, MAF, ICV and intakes very, very thoroughly. Clean the plenums and boots. Will be spotless.
Then I’m going to change the oil and drive the car hard. Spoke to a nearby tech and he said oil in plenums and manifolds is normal and more than likely indicative of not driving the car hard enough, or not taking it through full heat cycles when first started each day. He has changed AOS’s on these cars before and still sees oil get accumulated in the manifolds, mostly because the owner doesn’t take it from dead cold to operating temp, or they don’t drive it like it should be driven. If it still idles like sh*t I’ll change the AOS.
Will keep ya’ll updated.
10-18-2023, 04:42 PM
#22
Rennlist Member
I agree with allcool. The shotgun approach isn't the best way (time and money) to fix the problem.
You need to understand the problem first. Has the car produced any codes? I asked this some posts ago and these codes are pointers to where to start looking. Share the codes with us.
You need to understand the problem first. Has the car produced any codes? I asked this some posts ago and these codes are pointers to where to start looking. Share the codes with us.
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allcool (10-18-2023)
10-19-2023, 03:51 AM
#23
Racer
Thread Starter
Yeah my bad...typing too much. Posted codes in an edit on post #20.
"edit x2- and Yep I did get codes. Misfires on 5 cyls and enrichment limit from two O2s."
Imo the problem could be anything from bad coils, bad plugs, bad ICV, dirty TB, or bad AOS. I took both plenums off and checked vac lines - nothing. wiped down the plenums and manifolds of the tiny bit of oil they did have. Have been told it's normal (saw a post earlier saying it wasn't). I don't have my Autel anymore otherwise could rule out bad MAF or bad O2's (doubt it, just changed them a year ago). I actually think the loose connection on cyl 6's coil (rearmost, bank 2 - technically either cyl 6 or 4 can't remember) might've been it. Imo my approach has been pretty solid thus far and got a few new tools out of it that I'll use in the future...... cheers.
"edit x2- and Yep I did get codes. Misfires on 5 cyls and enrichment limit from two O2s."
Imo the problem could be anything from bad coils, bad plugs, bad ICV, dirty TB, or bad AOS. I took both plenums off and checked vac lines - nothing. wiped down the plenums and manifolds of the tiny bit of oil they did have. Have been told it's normal (saw a post earlier saying it wasn't). I don't have my Autel anymore otherwise could rule out bad MAF or bad O2's (doubt it, just changed them a year ago). I actually think the loose connection on cyl 6's coil (rearmost, bank 2 - technically either cyl 6 or 4 can't remember) might've been it. Imo my approach has been pretty solid thus far and got a few new tools out of it that I'll use in the future...... cheers.
Last edited by hkovalcik; 10-19-2023 at 03:56 AM.
10-19-2023, 09:35 AM
#24
Rennlist Member
Yeah my bad...typing too much. Posted codes in an edit on post #20.
"edit x2- and Yep I did get codes. Misfires on 5 cyls and enrichment limit from two O2s."
Imo the problem could be anything from bad coils, bad plugs, bad ICV, dirty TB, or bad AOS. I took both plenums off and checked vac lines - nothing. wiped down the plenums and manifolds of the tiny bit of oil they did have. Have been told it's normal (saw a post earlier saying it wasn't). I don't have my Autel anymore otherwise could rule out bad MAF or bad O2's (doubt it, just changed them a year ago). I actually think the loose connection on cyl 6's coil (rearmost, bank 2 - technically either cyl 6 or 4 can't remember) might've been it. Imo my approach has been pretty solid thus far and got a few new tools out of it that I'll use in the future...... cheers.
"edit x2- and Yep I did get codes. Misfires on 5 cyls and enrichment limit from two O2s."
Imo the problem could be anything from bad coils, bad plugs, bad ICV, dirty TB, or bad AOS. I took both plenums off and checked vac lines - nothing. wiped down the plenums and manifolds of the tiny bit of oil they did have. Have been told it's normal (saw a post earlier saying it wasn't). I don't have my Autel anymore otherwise could rule out bad MAF or bad O2's (doubt it, just changed them a year ago). I actually think the loose connection on cyl 6's coil (rearmost, bank 2 - technically either cyl 6 or 4 can't remember) might've been it. Imo my approach has been pretty solid thus far and got a few new tools out of it that I'll use in the future...... cheers.
10-19-2023, 12:57 PM
#26
Rennlist Member
Something else is causing this. I don't know enough about these engines (mine is different than yours), but the root cause is likely something that impacts both banks and all cylinders (despite one not throwing the code). In some cases, oil residue in the intake could be a vacuum issue or a problem with venting crankcase pressure.
Someone with more familiarity with your engine needs to step in. Also, keep in mind that the more detailed information you can share the better it helps us help you.
10-19-2023, 09:39 PM
#27
Racer
Thread Starter
Thanks for the help regardless. Put everything back together today and the idle has improved, but it's still missing ever so slightly (only at idle). Still smells like it's running rich. I ordered 6 new coil packs, a MAF and spark plug tubes. No smoke from exhaust and can still easily remove oil cap so ruling out AOS for now.
I replaced the spark plugs today and cleaned everything out (intake plenums, TB, Maf and ICV). New waterpump/coolant flush too but that's beside the point.
Imo has to be coil packs? Pretty crazy - had to've been from the guy's pressure washer. Got 1-day shipping on them so will update will good news (hopefully) soon. This has been really annoying and still hate that I spent $220 on that wash....
edit- and price not really an issue here because these are parts I've bought thru FCP before and will just send the current ones in for a full "refund" / credit (their guarantee policy is awesome)
I replaced the spark plugs today and cleaned everything out (intake plenums, TB, Maf and ICV). New waterpump/coolant flush too but that's beside the point.
Imo has to be coil packs? Pretty crazy - had to've been from the guy's pressure washer. Got 1-day shipping on them so will update will good news (hopefully) soon. This has been really annoying and still hate that I spent $220 on that wash....
edit- and price not really an issue here because these are parts I've bought thru FCP before and will just send the current ones in for a full "refund" / credit (their guarantee policy is awesome)
Last edited by hkovalcik; 10-19-2023 at 09:51 PM.
10-19-2023, 09:45 PM
#28
Race Car
When I had a dead injector on my Turbo is showed misfires on every cylinder *except* the one with the dead injector.
Easy to check. Start with engine cold. Run the engine for a minute then touch each exhaust runner.
Easy to check. Start with engine cold. Run the engine for a minute then touch each exhaust runner.
10-19-2023, 10:38 PM
#30
Rennlist Member
