P0021. What's the cure?
 

Got this code on the way into work this morning. The car started shaking at a red light and rpms were low. Reset the code and it went away. Never threw a engine light but it stored the code. After some quick reading it doesn't sound like a sensor but it could be oil pressure related. More common on the HR engine but I'm hoping it's not the gasket on the timing cover. Hours of labor for a $2 part. Any advice is highly appreciated
Background: changed the valve covers with cheapo Amazon ones about a year ago. Should I check for oil in the tubes?
https://cimg1.ibsrv.net/gimg/g35driv...ea45190d04.jpg

Fought that on my first Maxima the 4 years I owned it, never able to figure it out. Even removed the solenoids and blew them out. Changed camshaft position sensors, etc. Same issue, generally if I hit the rev limiter (easy to do on cold streets in the winter having to quickly pull out into traffic), go into limp home mode, have a stored code but no CEL. Turn off car, restart and it was fine again.

How often did this happen to you? It's been a few days of driving and it hasn't happen again. I even redlined it a couple times wondering if it's oil pressure related to see if a code would pop up. If it does, I'll check the solenoids. The more I read, the scarier this code gets

It would generally happen if I hit the rev limiter, or got on it too hard when the engine was cold. My car was using a quart of oil every 1500-1800 miles but I was good about keeping it topped off. My 2nd Maxima and my G35 both had/have much lower oil consumption (1 quart every 3500 miles/1 quart every 5000 miles respectively). No P0021 issues with either.

Yeah unfortunately a common cause for that code is the galley gaskets on that HR motor. I know you posted it in a V35 forum but you're specifically talking about your HR equipped sedan yes?

Did you ever try changing the vtc solenoid? It would be nice if they were interchangeable to see if the problem would go to bank 1. Fingers crossed it was just a fluke 🤞

No I'm speaking for the g35 DE. I see the gallery gasket is a common issue on the HR, but it seems to be the most common fix for the code. I'm just trying to look ahead and have a plan of attack. If the problem turns consistent, I think I would clean the solenoid and test that the plunger is opening/closing. Then check oil pressure. Then maybe drop the oil pan and check for a piece of a blown gasket

Ahhh ok, for some reason I thought you were driving a V36 sedan. In that case you should order a new gasket and o-ring for the VTC solenoid, then take your existing one off, clean it thoroughly with brakleen look down into the ports in the engine for debris, some years there is a metal pre-screen that needs to be removed with a dental pick to clean it as well. You can check for operation by applying 12v to the harness (don't hold it open for more than a second or so, usually you just tap it open and closed quickly you can damage the solenoid by holding it open with voltage), I strongly recommend you go down to a pick n pull and cut the harness off another donor vehicle for bench testing your existing solenoids.

Also measure resistance across the pins, it should be 7-7.5 ohms resistance, if that is out of spec then the solenoid coil got contaminated with oil or water and is screwing up the resistance so you'll need to buy a new one. This can be tested with the solenoid still installed on the vehicle. You should also NOT have any resistance if you measure either pin to ground (like the timing chain cover).

There are 3 separate magnetic solenoids that all open at the same time for 3 separate passageways, you will see the brass valves open/close and likely what's happening is one or 2 of them aren't opening all the way because they get gummed up with oil residue (oil isn't very clean at the end of your oil change cycle and all that extra **** tends to deposit in places like this). Spray it down REALLY well with the brakleen, let it air dry, then actuate it a few times and watch those brass valves open, it's really easy to see which ones aren't opening properly, keep spraying with brakleen (keep in mind it's flammable and playing with 12v to actuate those solenoids causes a spark so don't burn yourself), actuate, spray/dry actuate etc. If it's really super gummed up you can also soak it in Sea Foam just don't get the electrical harness wet.

This is one of those components that you almost never need to REPLACE because it can be thoroughly cleaned.

Something you will almost definitely find is that there are bits of RTV sealant blocking some of the passageways, on the neighbors G35 it appeared that the factory had used RTV during assembly and there were a couple small pieces wedged around the brass actuator that were really difficult to get out, I used wooden toothpicks and compressed air so I wouldn't damage the surfaces and it was a pretty painstaking process getting it all cleaned out properly. Mine didn't have any RTV just the gasket so I don't know if maybe someone has previously cleaned mine or if someone had used RTV when reassembling his.

Every one of these cam solenoids I've worked on because there was a DTC code attached has something that you could definitely tell was wrong with it except for one instance (cam sensor intermittent failure). Typically it something wedged into the actuator and you can SEE IT stuck in there or there's a lot of residue from old oil that is stuck on the walls and not actuating properly, a couple times I've seen solenoid oil contaminated ones that had wrong resistance readings (Chevy is notorious for this). If you can't find anything actually wrong with the solenoid then it could also be the cam sensor starting to fail. Technically the crank sensor starting to fail could be the culprit as well but you usually end up with a lot of other problems like stalling so I wouldn't consider it as the problem in this instance.

@cleric670@gmail Much appreciated. Gives me some peace of mind. Was hoping you'd see this thread!

I'll probably do this next weekend unless the code comes back. Gonna order some solenoid gaskets because I did reuse them when I changed valve covers and I don't think you are supposed to. Also, I know bank 2 is the driver side. But some of solenoids are listed as left/right. Would bank 2 be left or right?

Direction is always from your sitting position in the driver seat, left side is the USDM driver side, right side is the USDM passenger side.

Opposite if you have a right hand drive JDM car. That's why you don't use the phrase "driver side" because some of these vehicles that's actually on the right hand side of the vehicle.

No, we cleaned them out and they seemed to be fine. I was also getting the P0011 code too. Or I'd get one of those along with a cam sensor code.

I made a video I posted on FB on G35 driver group. I diagnosed EVERYTHING, checked my voltages and resistance. Sensors passed resistance test. They clicked with 12v. clean the screens on the sol. Almost gave up.

Hooked up Consult to it during the misfire and saw Intake cam retarded in comparison to the other bank. So It gave me hope to continue down the VTC path.
I went to the JY and brought a couple of solenoids home off the bat I realized the "plunger" on mines was out. This encouraged me to clean it and was able to get it working better however the code was still there.

Tried another solenoid and the problem was fixed, resistance between faulty ones was similar to working ones and they both clicked. It was during the 12v test where I realized the the "click" of the faulty ones was slightly lower and slower than the working ones. It's been 4 months since and I have not had that issue.

Dirty oil, noisy chains, and any type of pollutants will clog these. If it clogged then it will happen again, before you bite the NEW bullet, try a used one.

Yeah when the ECM actuates the solenoid it's a series of quick pulses so if they don't snap open/closed very rapidly it will not allow the correct volume of oil to pass through.

That's great. Thanks for sharing. I have a trip to the pick n pull planned this weekend
For cleaning, maf sensor cleaner should be suffice? Pretty sure I have a can of it just laying around in the garage

First time I got the code was days after I changed the oil. Guessing the new oil maybe cleaned out some gunk and had a hard time making it through the solenoid

MAF cleaner might not be strong enough to remove the varnish but it's worth a try. The most recent two I've done had debris physically blocking the brass plungers so it was just a matter of prying / spraying that crap out