Good evening, this is my first experience with an Infinity or a Nissan, and I'm having a bad mix of issues currently.
Car is a 2002 Infinity I35 (VQ35DE), currently sitting at 158080 miles (changed oil + filter [aftermarket filter] and transmission fluid + filter/gasket when I got the car at 154540)

For starters, my oil pressure light flickers when I'm off the accelerator or braking.

I also have 3 codes, P0011, P0021, and P0340, and autozone's scanner says I need to replace thee VCT solenoid.

I have also begun, as of yesterday, to have misfires in idle and occasionally while driving (I idle at around 750-850 RPM).

Most concerning of all, there's an increasingly loud rattle/knocking coming from around the throttle body/intake manifold. I will be attaching videos of the sound.

Last night at the hospital parking garage, while in 2nd gear coasting at 1500 RPM, it started to drop to idle, then back to 1500, back to idle ETC., and so I parked for a while and since this issue has not come back up. Another weird thing is that when parked and revving (1100-1200 RPM), after I let off the throttle it would rev to 1500 and then back down to idle. That issue has also not come back up.

While driving home from the hospital today, only once and corrected itself when I restarted the car, my slip and TCS light kicked on.

I'm honestly stumped and have done as much research as I could, and I'm leaning towards the gallery gasket going out and flooding the VCT solenoid. I'm honestly a car novice and learn as I need to in order to maintenance my vehicles. I need this car fixed ASAP to get to work (college student), and my commute is far and a rental isn't an option as I'm under the age threshold for that.

What tests can I do to be sure it's the gallery gasket? Could my oil pressure sensor just be acting up at the same time the VCT solenoid is clogged therefor causing the rest of the issues? I honestly have no idea, spoke to people at Nissan while getting price appraisals (mainly part numbers, though) and they suggested I change the oil and put on an OEM filter (which I did get today as I'm nearing an oil change)

Should I just order the solenoid + sensors now, replace them and see if that fixes the issues? Should I also just go ahead and order the gaskets and replace them? I understand it's not an easy job and a very long one at that, but my options now are either become self sufficient or die.

**For reference, I have not been running low on oil (positive of it, potentially overfilled by a quarter of a quart or so) and I use Mobil 1 Full synthetic, 5W-30 extended life w.e. Aside from minor misfires, the car performs excellent and has been. I also am not driving the car except to troubleshoot and get opinions.

https://drive.google.com/drive/folde...usp=drive_link

 

Oil pressure light, P0011 and P0021 all point to being low on oil. Immediately check and see if the oil level is low and add some. I think their is a VERY HIGH CHANCE that this is the root of your issues.

The VCT solenoids operate on oil pressure. Low oil / low oil pressure will cause P0011 and P0021 codes.

The VCT solenoids not operating properly due to low on oil will cause issues with how the engine runs and idles.

 

Thank you for the response!

Yup I was already about due for an oil change (use mobil one full synthetic, 5w-30 and just over 3k since last change).

I did that today, took a look at both cam sensors and the solenoid towards the radiator (side mounted motor, pretty sure bank 1?).

I was at around 3 quarts of oil, little over, definitely low on oil. My dipstick was showing plenty of oil on one side (of course), and the other side ABOVE the H line and into the little crevis. No idea what this is about, I had been regularly checking this.

Interesting thing is now I have a misfire at idle, relatively bad and pops up as a general misfire. Also P0021 is back.


Going to be taking a look at the 2nd solenoid tomorrow morning, and possibly hit up a junkyard to get a replacement, I also discovered I have a valve gasket leak (assuming since its burning up under the intake manifold and the area below it is saturated), so fun times ahead, not a major leak however. Curious as to if that leak can cause the misfire at idle. Noises and the other issues are completely gone as well, awesome call, just worried I got to it a little too late. Any more suggestions on what to check now and advice is greatly appreciated, have a great night brother thank you so much once again.

 

The oil takes forever for it to go to the pan after shutoff so a proper oil check is to let it sit overnight and check in the morning.

If the oil and brake light starts to flicker, you have a failing alternator so keep that in mind as well.

 

My daughter let the oil run low on her/our 2003 Maxima. Same symptoms and same codes.

I brought her home from the hospital in that 2003 Maxima when she was born. Now it is hers. We changed all the spark plugs, coils and fuel injectors when she started driving it. It wasn't too expensive since we did it all our selves... just a few hundred dollars for parts from rockauto.com

 

Yup positive low oil is what caused all of these issues. I do believe now that BOTH of my valve covers are leaking so there's another fun day coming up next week... I cleaned the bank 2 solenoid this morning and double checked all my wiring and the misfire when idling seems to have gone away, although I was test driving and when I was coming to a stop, it misfired for a moment, no code attached. Couldn't recreate that either, I assume maybe the ECU needs time to relearn everything? Unsure

 

always check the oil before starting the car, at least once a week. oil consumption is the way of life when it comes to the VQ35. if you do the valve covers you will need new valve covers because the seals for the spark plug tubes aren't serviceable. get a decent set. the cheap sets come with cheap gaskets that get hard and will leak fast. I recommend getting silicone valve cover gaskets that are usually blue. you also want to change the O-rings for the cam position sensors. when those get old they will leak oil all over the connectors and can cause the car to shut off while driving.

 

My son's 03 I35 consumes about 1/2 QT of oil per 250 miles. We add 1/2 QT of oil with each gas fill up. Some VQ35DE's use more oil than others, so it's very important to keep an eye on it.
Cheap Amazon coils will make the car run bad as well, stick with OEM NGK plugs and Hitachi coils from RockAuto.

 

any ignition coil from Rockauto is better than the crap on Ebay and Amazon lol. Ive been running the Ultra Power brand coils with NGK laser iridium plugs and they work great. you never know what your getting when you get cheap unbranded parts from eBay and Amazon. I've even heard of counterfeit spark plugs being sold on eBay and Amazon. the only thing i experienced making a difference when going with OEM vs aftermarket is the MAF. my engine idles way smoother and seemed to pull harder when I switched from a Duralast MAF (that I got cause I needed it right away) to a used OEM MAF...

 

We are running the most expensive coils on RockAuto for all 6 cylinders. Same with all 6 injectors. After about 1.5 years we have had no problems with either. Both are a fraction of OEM (Dealer) replacements. I can't tell you which plug/coil/injector made a difference but the difference was huge and immediate in how well the car runs. The total cost was ~$625 which is about what I would have paid a garage to replace just one of each. For some reason I ordered 8 NGK plugs. I assume that they were cheaper in a 4 pack than individually?



HITACHI FIJ0001 (New) Info
Terminals: 2; Fuel Injection Type: PFI; Male Terminal; Blade Terminal
HITACHI Warranty Information
12 months/12,000 miles

No longer covered under the manufacturer's warrantyIgnition : Ignition Coil

NGK 48845 (Standard Replacement) Info
NGK Warranty Information
Spark Plug Wires: Limited Lifetime; Ignition Coils: 3 Years / 36,000 Miles; All Other Parts: 60 Days

Request Warranty ReplacementIgnition : Spark Plug NGK 4469 (Iridium (lasts up to 4x longer than Copper / Nickel)) Iridium IX; Pre-Set Gap: 0.044" Info
OE-Recommended Gap: 0.044"
NGK Warranty Information
Spark Plug Wires: Limited Lifetime; Ignition Coils: 3 Years / 36,000 Miles; All Other Parts: 60 Days

8No longer covered under the manufacturer's warrantyIgnition : Spark Plug / Ignition Coil Boot

 

when it comes to injectors I usually send them out to Injector Rehab. they are good at servicing them and include a flow chart that shows before and after.

 

Hitachi is an OEM supplier for Nissan so it's always a safe bet when you order their electronics and parts. The cars are sensitive when it comes to MAF, coils, and the cam sensors.

 

I actually took a chance with an Ultra Power injector from Rockauto on my Sienna van and a week later it went bad. got a used OEM one from the junkyard real quick and the van runs like new again at 507,000 miles. it's been 3 weeks and so far so good. havent had any injector issues with the maxima yet. before i put in the 7th gen engine I let the injectors sit in injector cleaner for weeks before actually doing the swap.