I've been having this problem for about a year now.The idle is typically fine in park/neutral, meaning 99% of the time it will not do it but on occasion I have had it happen in park/neutral. In drive at idle is when it typically happens. It does also happen when driving but at low rpms, won't happen above 2k I believe (unless the high rpm is just masking it, I don't know)

I'll pull up to a light and the rpm dips 100 or so and then comes right back up instantly. It'll usually do this dance 4 or 5 times then mellow out then start again. No absolute pattern to it though, sometimes its twice sometimes it's an endless stream of little dips. The car rocks back and forth with every drop.

I can force the car to do it by staying in drive and putting the parking brake on, then turning the A/C on full blast. It does it pretty bad like this. With the hood popped open the whole engine rocks back and forth and moves the whole car with it.

This is what I've tried so far:

Checked for vacuum leaks, can't find any. Torque app is identifying a vacuum of 22hg at idle. 18hg or so in drive. From what I've found that's normal.

Disconnecting coil packs 1 by 1. I wait until it's stuttering then I'll pull a plug to see if it won't make any difference. They all make it idle even worse to the same degree. I've also tried pulling power from the 3 injectors in the front with the same result.

I bought 1 lower and 1 upper coil pack and tried swapping both left, both middle, both right. No dice.

Changed spark plugs. No difference.

I tried cleaning the IACV. It was pretty dirty and black, I cleaned it up with carb cleaner. This didn't really make a difference. I might even say it's worse but that may just be perception.

Cleaned MAF and saw no difference. Tried running with MAF unplugged, still chugging. Bought a new MAF. No difference.

Tried unplugging TPS, still chugging.

Tried installing some grounds. My door open chime is slightly louder, that's about it.. still chugging.


I'm running out of ideas at this point. The car isn't even throwing codes (I check regularly with Torque), no CEL. Hope you guys can help. Thanks.

Here's a video of the shenanigans, it's much more dramatic in person. It looks slight twitch in the video for some reason, but look at the radiator swinging back and forth. It seems to me like it's linked to that "click" when the fan comes on.


EDIT: Forgot to mention this only seems to happen once the engine is warmed up.

Which spark plugs?

Just cuz you pull a coil pack doesn't mean the car won't run like ****. Pulling a coil pack only determines a DEAD pack...not a failing one.

I installed NGK PFR5G-11. Exactly what was listed in the FSM.

So, what are you suggesting? I may have more than 2 that are failing at once? I swapped my 2 new ones in all positions. First in 1-2, took a drive, then 3-4, took a drive, then 5-6, and took a drive. Didn't find any difference any of those times.

That click, sounds the a/c compressor coming on, or are you doing something else to make it do that. you may have a failing compressor, causing excess load. Would need to see what the a/c guages are doing to determine that however.

There's an electrical load also.The fans are coming on also. Do you have a dvom.? Have you Checked (+) voltage as this is happening..? The car should idle up with a/c engagement.

What do the actual plug boots look like. Pull them off the coils, inspect them. dielectric grease?

Check the harness on the pass side of the engine (along side the strut tower/ and engine) they break in the sheathing and can do odd things when the engine is put into gear. It shakes them causing issues.

This in unrelated to the cause of the shaking but how does your radiator support look? My auto max had the shakes too and the rad shook just like yours and made metal on metal contact sound becuase the support was very bad

I'm not doing anything but standing by and recording in the video. The car is in D, AC is on full, fan is on 4, and parking brake is on. That's it.

Also, I just remembered (I added it to my post up top) that this only happens when the car is warmed up. Even if there is minimal electrical load. No a/c, no headlights, no radio, nothing. It's just that I can get it to do it immediately if the A/C is on.

Yes, I have one. At which points should I check the voltages? Battery (+) to ground? I've noticed that the idle goes up by 75-100rpm when I turn the A/C on then it'll slowly work its way down.

They look almost the same as the new ones I bought. No cracks, etc. I used dielectric grease with a q-tip when I installed.

****, you may be on to something. I just went outside and found this..:



See that part without insulation? Could that be an issue? Should I tape it up?

It looks like ****, like most in this area do.

i wouldn't even drive that maxima with the rad support looking like that. one big bump or a small accident and that car is toast. you need a lower oem rad support and to go through and check: every hose, every wire(s) all connections and do a scan on the car after your done.

Sorry waka, I didn't read where you had 2 new coils.

Maybe injectors?

Waka, that untaped wiring area needs work. Not just because it is untaped, but because that red wire looks nasty. At best, it's corroded. More likely, it is causing extra resistance in some circuit.
I don't know what that wire does, but fix it. Something might function better after it is .

Since that section of red wire has corroded, a proper fix involves cutting the wire back about an inch in both directions, then spacing in a short section of new wire of the same or larger guage. Tape well when done.

No worries. I've been wondering about how to test the injectors out. I tried listening to them by putting my ear to a big screwdriver. The ones I have access to seem to be tapping away normally, but I guess that doesn't really tell me a thing about if the spray is irregular or not. I guess I could try ordering some remanned injectors to test swap. The ones under the intake manifold are gonna be a *****... luck would have it that those are the ones...

Looks like I've got a project for this weekend then. I'll report back if fixing that up has any effect. Worst case I'll have prevented another problem in future..