Hello guys, owning a 350Z for 3 months now, while tuning the car we noticed the vvt remained at the same levels during driving with Uprev logging.

Bank 1 is at -3.5/5 whereas bank 2 is at +19.50/20 but remains that way during load. There are no error codes showing up on OBD nor does the car run bad at all, however the car does not seem to respond regarding timing adjustment. +20 is a little excessive imo. Let alone it doesn't seem to do anything.

Now the advice i got is change the cam sensors/solenoids, but could it be possible that the solenoids are dirty and cannot do their job?

The Z should be more powerful in the lower rpms, at the top there seem to be less powerloss but it's definetly not at peak performance.

My Z is a 04 model with a DE engine.
Mods done to the car are Injen CAI and Invidia catback.
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Thanks in advance, i could just try and replace all the sensors and the solenoids but if the issue might be easier to solve that'd be great.​​​​​​

 

You can put a volt meter on the cam solenoids and see if theyre getting voltage.

Are you getting duty cycle variations from when the car is running? (Can you monitor/data log VTC duty cyle through Uprev?)

You can take the solenoids off and clean them. You can actually take the solenoid out of the housing to inspect and clean as well. They just bolt in with a 10mm bolt. Check wiring too - make sure the wire didnt sever right at the connector.

Your cam solenoids are sorta the gate keeper of the VTC. The driving force is really oil pressure. If you have oil pressure issues than there is not enough pressure to hold the VTC cog gears at the commanded advance.

Have you rebuilt your engine recently or had the front timing chain cover off the car?

How old is the car? How many miles on the car?

Also there is a split gasket/washer in the timing chain case cover that goes over the cog gear and there are o-rings in the timing chain case that all need to be sealing in order for VTC to work properly.


Post #1174, #1178, and #1186 on page 24
https://my350z.com/forum/forced-indu...l#post11036934

 

Hello and thanks for the reply.

Mine is a 04 DE with 187.000kms on it.
I have not rebuilt the engine nor is it taken apart.

Here i have some screenshots of the logging, the car is standing still but no change is seen during driving.
At the moment i have no access to Uprev as i do not own it myself. How do i measure the voltage of the solenoids with the connectors on? I am a terrible electrician. I do have a multimeter.

I can however try and remove the solenoids, but will i need a new gasket? Heard it doesn't sell seperately.

 

Just unplug the connector and take a voltage reading with the car running … the solenoid runs off a duty-cycle so the voltage reading may be erratic but you want to look for any voltage reading. I think you will need someone to blip the throttle as I dont know that the ecu is going to advance the timing while simply idle’ing the car - does this make sense? Did you see in my videos how the VTC moves when I give it a little gas?

You wont need a new gasket if you take the solenoid off…just be careful not to damage it. Do not take the solenoid off while the car is running.

You may have to take off that front cover and check the o-ring. If you are an inexperienced mechanic than do not attempt this yourself as they are sorta tricky to get back in and you may need a new o-ring.

and it may be a sensor issue too … these sensors are known for going out.

 

Hello and thank you,

Yes, this makes sense. However i don't think it should activate when not driving under load?
I can check the voltage, i'm looking up how to test the solenoids. Gonna try and find your videos!

Do sensors go out and not throw codes?

O-ring i am not sure where this one should be. As far as i can see, the car is all dry and not leaking or sweating oil.
Will try to remove solenoids, clean them and check further issues if not working.

I'll keep posting. Thanks!

Edit;

Found your videos. Also read eventually it was broken vtc sensors? Might just wanna switch those anyway and clean the solenoids.
Thanks!

 

The solenoid is activated per the VTC table within the ECU.

You can see from my video that the throttle blips caused movement on the VTC function with no engine load and parked - so dont assume you have to have significant amounts of load on the engine in-order for them to activate.

Thats a good question - my gumption is that as long as the ECU is seeing a good signal then no code would be thrown … but I’m not sure.

The orings are internal to the timing chain case, so if they are leaking or not holding pressure than oil would just leak within the timing chain case.

My issues were the split o-ring within the timing chain case and sensors. It should be noted I’m using a standalone ECU that is relatively different than the OEM ecu.

Let us know what you find.

 

Thanks so far, i'll need the car until the weekend but i'll get to it straightaway in the weekend. First i'ma check connections and signal, pull out the solenoids and do a cleaning and see if it helps. I'll have a appointment at Nissan Sports dealer next friday to see if they can look into the software and see if they can do something about it, and if my issue has resolved then it should show up too.

I'll see from there on! I'll keep ya posted. I have been watching videos on how to service the solenoids, should be doable.

 

Well, so today i checked voltage on my sensors. They seems to work and indeed, voltage fluctuates a bit when revving. Took out vvt solenoids, disassembled, cleaned and tested them but so far no problems and are in working order.
However when assembling the vvt solenoids and putting them back on the engine, the last bolt i tried to torque broke, with only about 7Nm on the wrench. Either the bolt was bad or my wrench is f-cked..

So i'll have to get that sorted in the morning. I'll keep posted if the issue has resolved or not.