VTC Click

[Jet-Lee]

From what I've read, rebuilding or new install will just go bad again in about 25k miles on my 1993 Maxima. Can I just take an exhaust cam gear, put it on in place of the VTC assembly and plug off the solenoid and be done with it? Maybe use an adjustable cam gear and dial it in to about 4º advance, between 0º and the 8º the VTC gives?

Thanks for your input.

[Nahkapohjola]

Originally Posted by Jet-Lee

...plug off the solenoid and be done with it? ...

- what I read, typical VTC complaints start after 100k. Cannot see any fact why proper repair would last less. I guess its a costly repair, my opinion: is not worth the investment. [but then what do I know...]
- lots disinfo around...
- ppl claim that just grounding the solenoid ctrl wire will stop the noise. Looking at the schema, no grounding is needed. Just disconnect the ctrl solenoid connectors, see FSM p.9 Wirings Foldout. This should close the VTC valves, and they will if solenoid(s) spring(s) do their job. Check... if not, try pluggin the solenoid.
- As u suggest, freezing the intake camshaft adv adjustment system this or that way will surely take noise out.
- The power curves I've seen show main VTC pwr boost effect starts after 5k rpm, so youll lose few hp... This contradicts what FSM tells, so cannot really know. ...see FSM page EF & EC 165,174
- click below: 'Favorite Links'

[Jet-Lee]

Thanks for the quick reply. I've grounded the solenoids, it only made the other one start clicking, now I sound like a diesel.

I'll try unplugging them completely.

If that doesn't work, would an exhaust cam gear fit on the intake cam? i.e. do the have the same shaft diameter, key location vs tdc, etc.? I'm having trouble even finding an OE exhaust cam gear.

[Nahkapohjola]

Originally Posted by Jet-Lee

I...'m having trouble even finding an OE exhaust cam gear....

As the system is hydraulics powered, blocking oil flow should keep the cams at zero. (If theres a spring loaded system pulling it home, that is, and hydraulics pressure effects the advance). I'd figure out a way to find a oil resistant rubber piece, plugit. Possibly taking solenoid out and pluggin the solenoid.
(As said, I have VG30E -engine, no hands on experience, no idea of dimensions...)

[Jet-Lee]

I'll look into plugging it. I've also read that the clicking is caused by bad springs due to lack of oil? If that's the case, would blocking it off do anything at all?

I'm really gonna dig into this VE30DE tonight.

[Nahkapohjola]

Originally Posted by Jet-Lee

... bad springs due to lack of oil? If that's the case, would blocking it off do anything at all?...

If hydraulics lack designed pressure, 'anythin' is possible. Dirt blocked flow is typical on lifters, there cleanup helps (some dealerships do this on all vehicles periodically). If oilflow becomes blocked, the lifters (why not VTC) will be soon worn out. The sound is much worse than a diesel: last year my opel oil flow to lifters were cut, 1k miles and it broke down... I guess a plastic bit from filter caused the almost total block. (Pays to peek into filter before installation.)

Check out the p. EC-174, VTC exploded pic:
1. ECU gives VTC advance command:
- the solenoid is activated (gets +12V) and this blocks flow, oil pressure builds up in VTC, system rotates =advances cam. (no advance command while idling).
2. No Advance:
- the solenoid is NOT activated (NO +12V), solenoid remains open and oil pressure escapes via solenoid, no VTC oil pressure buildup, no cam advance.

If click in case 1, only freezing the VTC adv mech helps. Solenoid grounding is balooney. I guess VTC may be opened and something can be fabricated to keep the advance mech in desired position.
If click is in case 2, then blocking, or rewiring solenoid to +12V may hlp.

Note that cam adv pos might have some effect on mpg, so figure out where u want to freeze it.

[Jet-Lee]

Originally Posted by Nahkapohjola

Check out the p. EC-174, VTC exploded pic:
1. ECU gives VTC advance command:
- the solenoid is activated (gets +12V) and this blocks flow, oil pressure builds up in VTC, system rotates =advances cam. (no advance command while idling).
2. No Advance:
- the solenoid is NOT activated (NO +12V), solenoid remains open and oil pressure escapes via solenoid, no VTC oil pressure buildup, no cam advance.

If click in case 1, only freezing the VTC adv mech helps. Solenoid grounding is balooney. I guess VTC may be opened and something can be fabricated to keep the advance mech in desired position.
If click is in case 2, then blocking, or rewiring solenoid to +12V may hlp.

Note that cam adv pos might have some effect on mpg, so figure out where u want to freeze it.

If I'm reading this right, grounding the solenoid creates a constant #2 condition, right? It's always open, no advance.

I'm going to try, first, giving the solenoids a constant +12v and see if that helps. If not, I'll try unplugging the solenoids completely. If neither of those help, I'll try blocking off the solenoid. Then I'm looking into the exhaust sprocket idea.

[Nahkapohjola]

Originally Posted by Jet-Lee

If I'm reading this right, grounding the solenoid creates a constant #2 condition, right? It's always open, no advance.

I'm going to try, first, giving the solenoids a constant +12v and see if that helps. If not, I'll try unplugging the solenoids completely. If neither of those help, I'll try blocking off the solenoid. Then I'm looking into the exhaust sprocket idea.

Yes.
I agree to your plan. Pls inform how it goes, lots ppl are in need of exact info.

Electrically the VTC ctrl solenoid is a magnetizing coil. One end is always connected to gnd =ground. The other 'end' is connected to ECU.. ...time to time ECU output is activated = solenoid gets +12V = oil flow blocked.
...connection is like this:
ECU (+12v-or-gnd)-----coil-----gnd

What does the solenoid balooney grounding actully mean?
...connection will be like this:
gnd-----coil-----gnd
--->solenoid stays always open, never oil pressure up & cam advance. The very same happens if theyre disconnected.

Edit: start from checking coil resistance

[Jet-Lee]

Ok. I tried powering the solenoids, nothing. So I tried "grounding" them again. Nothing. So I ran wire to the - post on the battery, and it stopped! Why this worked instead of grounding it, I don't know.

Now it appears that I have a little lifter knock. Dammit.

Is there a way to tell if the oil in cyl #6 is from a headgasket or a ring?

[Nahkapohjola]

Originally Posted by Jet-Lee

Ok. I tried powering the solenoids, ...

- Powered, functional, VTC solenoid (gets +&-):
Oil cannot 'escape'. As a result, pressure builds up in cam channels and VTC, its work 'cylinder' is filled, 'piston' moves, cam adv mech rotates.

Now this oil pressure keeps the mechanism pushed in most advaced position. Worn spring doesnt count, adv mechanism cannot keep clacking.

- Things which might help lifter clicks: seafoam cleanup, original Nissan filter (right oil bckpressure), different oil, snake oil additives.

- If #6 plug doesnt display any anomalies (see www.ngk.com), cyl pressure ok, I would not care. Cooling liquid & oil are clean?