2003 Occasional Stumble at Idle Only in Gear
10-21-2021, 07:16 AM
#1
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Join Date: Jan 2003
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2003 Occasional Stumble at Idle Only in Gear
'03 Maxima with 152k miles. Problem started a month or so ago and slowly getting worse. Mostly when warm (but sometimes when cold), at idle but only in gear, there's a stumble every several seconds and tach dips slightly. Idles a bit rough in P or N but no stumbles, and runs fine when driving. Suspected IACV but seems either it's built into the throttle body or there isn't one. Was going to clean the throttle body but found several posts that this causes error codes and then need to bring to dealer to reset ECU, learn idle, or both.
I could bring it to local mechanic and have them clean it. Don't want to replace TB if it's just dirty.
Other posts suggest PCV or camshaft sensor. I'd think that since this happens only in a very specific situation (in gear) that the symptom would lead to a specific part being bad, but evidently not. It's a bit tricky to troubleshoot in real time since car needs to be in gear, so would need to have someone else in the car with the wheels securely blocked.
So any ideas? It's a second car so not dead in the water if I mess up, but then I'd likely need it towed somewhere.
BTW, what differentiates a 5th gen from 5.5 gen?
I could bring it to local mechanic and have them clean it. Don't want to replace TB if it's just dirty.
Other posts suggest PCV or camshaft sensor. I'd think that since this happens only in a very specific situation (in gear) that the symptom would lead to a specific part being bad, but evidently not. It's a bit tricky to troubleshoot in real time since car needs to be in gear, so would need to have someone else in the car with the wheels securely blocked.
So any ideas? It's a second car so not dead in the water if I mess up, but then I'd likely need it towed somewhere.
BTW, what differentiates a 5th gen from 5.5 gen?
11-01-2021, 07:19 AM
#2
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Hmmm, so no ideas? I'm trying to understand what would cause the idle stumble only in gear and not in N or P, and whether it's a mechanical (idle air control valve/solenoid) or a software issue (ECM). Mechanical problem seems more likely but why only in gear... does the idle control go into a different mode?
Load in engine would be different, but that seems to be the only thing different, other than that the ECM would know it's in gear. Maybe I'll try turning on the A/C at idle in N or P and see if the issue is from any load or an in gear load.
Could a sticking valve/solenoid cause this? Nervous about cleaning the throttle body and don't know if I can get TB cleaner up into the valve/solenoid without completely messing up the TB.
Load in engine would be different, but that seems to be the only thing different, other than that the ECM would know it's in gear. Maybe I'll try turning on the A/C at idle in N or P and see if the issue is from any load or an in gear load.
Could a sticking valve/solenoid cause this? Nervous about cleaning the throttle body and don't know if I can get TB cleaner up into the valve/solenoid without completely messing up the TB.
11-11-2021, 06:04 PM
#3
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Update: Had local shop do some diagnostics. First they confirmed the issue... stumble at idle only when in gear and stopped. They found steady intake vacuum at intake manifold so not an air issue. Steady fuel pressure so not an injector. felt a suck instead of a blow at the tailpipe when engine stumbled, leading them to believe an exhaust valve not seating. If true, that's not an easy or inexpensive repair.
I've replaced 2 coil packs in the past, and this stumble feels a lot like a bad coil, but no codes so not easy to tell which cylinder. Going to keep driving it until I get an error code, likely a misfire code, which should isolate to a cylinder. Hopefully it'll be a front bank (easy) and not rear (PITA) and I can try swapping coil packs to see if the issue moves with the coil.
I've replaced 2 coil packs in the past, and this stumble feels a lot like a bad coil, but no codes so not easy to tell which cylinder. Going to keep driving it until I get an error code, likely a misfire code, which should isolate to a cylinder. Hopefully it'll be a front bank (easy) and not rear (PITA) and I can try swapping coil packs to see if the issue moves with the coil.
11-12-2021, 08:01 AM
#4
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I have a 2000 Maxima 3.0 with a 5 speed. I believe in 2002 they switched to the 3.5. I've read on here that Nissan doesn't use an IACV on the 3.5. I do believe your answer will be on this forum. I found just searching the forum, instead of asking, is the best route. I've fixed many things, sometimes for free, by searching. Hope you find your answer. An intermediate miss is sometimes the hardest thing to fix. Good luck
11-12-2021, 04:54 PM
#5
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Location: Montreal, Quebec
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what you need in a fancy computer that has live data running while this is happening then it would tell you exactly which parameter is going in the red, how far is Scotty Kilmer from your place?
What I find strange is if it only happens with the brakes applied in gear it could be the torque converter that's showing signs of wear since it's at that time that it's under stress, if you put it in neutral and it goes away? why would it go away if there is an fuel or ignition problem? it should also stumble in neutral in those cases
I would still definitely clean the TB and MAF with some specialized spray cleaner, you must follow a specific procedure for this (disconnecting battery and stuff) on the 3.5 motor since the computer and the throttle position sensors might get all confused if you do it with things plugged in
What I find strange is if it only happens with the brakes applied in gear it could be the torque converter that's showing signs of wear since it's at that time that it's under stress, if you put it in neutral and it goes away? why would it go away if there is an fuel or ignition problem? it should also stumble in neutral in those cases
I would still definitely clean the TB and MAF with some specialized spray cleaner, you must follow a specific procedure for this (disconnecting battery and stuff) on the 3.5 motor since the computer and the throttle position sensors might get all confused if you do it with things plugged in
11-15-2021, 06:00 AM
#6
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> ...if it only happens with the brakes applied in gear it could be the torque converter that's showing signs of wear...
I'd thought of possibly a tranny issue, but the tech said that he could definitely feel a change in the exhaust pressure at the tailpipe when it stumbles, and he did hook it up to a fancy computer that has live data running while this is happening.
I'd thought of possibly a tranny issue, but the tech said that he could definitely feel a change in the exhaust pressure at the tailpipe when it stumbles, and he did hook it up to a fancy computer that has live data running while this is happening.
11-17-2021, 11:42 PM
#8
11-18-2021, 08:50 AM
#9
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Location: Kissimmee FL
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have you tried cleaning your throttle body or doing a relearn on it? what's the voltage at while running? from my experience with these cars the throttlebody is the first thing to act up when voltage gets low. the throttle body is what controls the idle.
11-23-2021, 09:47 AM
#11
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> Which coils did you replace, and did you replace them with OEM coils or aftermarket coils?
Don't recall, was years ago. Believe they were aftermarket coils. Doesn't appear there's any way to test them while in the engine so hopefully I get a "Cylinder Misfire" code for a while before it goes to limp mode.
I have another car so not a huge inconvenience.
> just put it in neutral whenever you encounter stops/traffic,
I do, as needed.
> what's the voltage at while running?
I'll check. When I had it inspected recently, they said the battery was getting a bit weak, but it's been starting fine here on cold (<30F) mornings.
Don't want to invest much into it. Hoping it'll last into next spring/summer when I'll likely replace it with something a little more fun.
Don't recall, was years ago. Believe they were aftermarket coils. Doesn't appear there's any way to test them while in the engine so hopefully I get a "Cylinder Misfire" code for a while before it goes to limp mode.
I have another car so not a huge inconvenience.
> just put it in neutral whenever you encounter stops/traffic,
I do, as needed.
> what's the voltage at while running?
I'll check. When I had it inspected recently, they said the battery was getting a bit weak, but it's been starting fine here on cold (<30F) mornings.
Don't want to invest much into it. Hoping it'll last into next spring/summer when I'll likely replace it with something a little more fun.
12-21-2021, 06:34 PM
#12
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Join Date: Mar 2004
Location: 32 miles north of Nissan AZ Proving Grounds
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Your issue sounds like a dirty TB, based on mileage and symptoms (assuming I am interpreting correctly). Take off the intake tube to inspect - a dirty TB will show a noticeable black ring around the perimeter of the TB at the butterfly as well as on the edges of the butterfly.
Yes, cleaning the TB can be difficult with respect to the idle re-learn. To paraphrase a few other .org threads on this subject, I used the TB on-car method involving opening the TB by depressing the accelerator pedal and holding it open with a tennis racquet braced against the seat, careful to not move the butterfly - just clean lightly on the half that's exposed. You can still get the port of the TB very clean w/o risk of touching the butterfly.
The re-learn did not go very smoothly for me. I had to do the more aggressive approach of unplugging 3 fuel injectors to lower the idle speed during the process.
As for coils, always use the OEM equivalent Hitachi IGC006 from Amazon or RockAuto. Cheap and reliable. You can replace all but 2 of them w/o removing the intake manifold.
And with respect to the inquiry about voltage, our cars do tend to have a "lazy" alternator that allows the voltage to dip (headlights dim) at idle, especially when all the accessories are on and the temps are hot.
5th gen = 2000-01 w/ 3.0L
5.5gen = 2002-3 w/ 3.5L (VQ35DE), 6-speed (if MT), HID headlamps, chrome bezel tails, and other minor differences.
Yes, cleaning the TB can be difficult with respect to the idle re-learn. To paraphrase a few other .org threads on this subject, I used the TB on-car method involving opening the TB by depressing the accelerator pedal and holding it open with a tennis racquet braced against the seat, careful to not move the butterfly - just clean lightly on the half that's exposed. You can still get the port of the TB very clean w/o risk of touching the butterfly.
The re-learn did not go very smoothly for me. I had to do the more aggressive approach of unplugging 3 fuel injectors to lower the idle speed during the process.
As for coils, always use the OEM equivalent Hitachi IGC006 from Amazon or RockAuto. Cheap and reliable. You can replace all but 2 of them w/o removing the intake manifold.
And with respect to the inquiry about voltage, our cars do tend to have a "lazy" alternator that allows the voltage to dip (headlights dim) at idle, especially when all the accessories are on and the temps are hot.
5th gen = 2000-01 w/ 3.0L
5.5gen = 2002-3 w/ 3.5L (VQ35DE), 6-speed (if MT), HID headlamps, chrome bezel tails, and other minor differences.
Last edited by CRBWS6; 12-21-2021 at 06:57 PM.
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