I was just thinking about it (was a few months ago too but meh) and I dont see how the clacking can rob power? I dont think it would, I can feel a big difference between grounded and not grounded. But I think rebuilding them only really fixes the clacking. My only idea is that the VTC isnt being "expanded" all the way, therefore the cam isnt being fully advanced

I'm probably going to snag some from a few other motors and look for any design differences (unless they have a breakaway in the FSM, which I doubt) that could lead to a permanent fix to the noise lol.

 

Boy that'd be great. However I sometimes feel a hesitation right around 4,500 rpm...and right around that same rpm (4,600 according to FSM) VTC's "shut off". Don't know if that's cause my VTC's are bad or not (they do tick), but if it is then that might shoot down your theory.

 

thats probably the VTCs "switching over"

I dont really notice any real bumps or blank spots in the powerband, but I can tell when they are grounded, the engine feels like its fighting itself to pull to redline where when they are ungrounded it just pulls so much faster.

 

I'm unfamiliar with VTC's and I've read conflicting information so I don't know who to believe

 

me too

 

Hmm, interesting. Well this brings me to the question...is there any documented case of bad VTC's hurting an engine? I've been here for a year and a half and I don't think I've ever heard or seen any real evidence that clicking VTC's are causing harm.

 

I've never seen any, or atleast any I can remember.

I dont even care enough to spend the $80 to do before and after dyno's

 

the thing is, that at high rpm the vtc's have to turn off, so the new springs are stiffer, and therefore stronger or faster at turning them off. So figure when your running the car hard and going through gears, the vtc's have to turn on/off fast, to recover the timming making peak power.

There was some talk a long time ago, with a couple people mentioning failure, but I think it was mis-diagnosed b.s.

 

Its hard to tell what exactly is causing the noise. Most people think its somthing to do with the lifters and the valve train, but I don't think thats the case. Now that I've opened them up, I think its the split helical gear inside the vtc thats whacking in harmony with the sping trying to shut the mechanism down.

It must be (now that I think about it) one of the techniques is to listen in on each vtc to find out which one is making the noise, isolating it, but focusing on the noise generated by the individual vtc (they should both be rebuilt regardless).

 

oh just rebuild them already, LOL

 

Well my guess is that the spring is too weak to keep the gears pushed up so its letting it move back and forth and that couldnt help performance. I may be wrong but if its clacking then its not holding like it should so it will not run like it should.

JMHO though. I dont care though because I have nice working VTCs anyway .

 

Ouch, you just had to throw that in there didn't you...and on Christmas even!

 

I thought the car that Portdave replaced the engine in had some kind of VTC failure? I can't remember, I just recall seeing a busted up timing chain cover.

Also, the car Yourself had up near MrGone claimed the VTCs failed.

I have a spare set of rebuilt VTCs in the garage, but now I don't want to mess with it after all of the stuff that happened before.

 

Eric/Michael, I am confident the noise is coming from the VTC assembly itself. On one set I pulled apart there were grooves worn in the base part of where the spring sits, about 3mm wide (so the spring must move around alittle). I dont believe that car had its VTC's grounded though and was driven by a grandma for the most part. I have always wondered though, if the noise came from that inner 'gear' part or just the spring 'jumping' or something. The spring idea seems to make the most sense to me, although I was surprised to find out the middle gear part actually moves seperately, hmmmm.

 

what noise do VTCs make when they go bad?
Mine don't make noise
but the VE with leather and a bad coil supposedly makes noise on startup.

 

[QUOTE=Red92MaxSE]I thought the car that Portdave replaced the engine in had some kind of VTC failure? I can't remember, I just recall seeing a busted up timing chain cover.

Also, the car Yourself had up near MrGone claimed the VTCs failed.(it was a gxe)

ha ha thats funny im so mysterious people dont even know what im workin wit
i think i was tellin fools about the torque converter breaking (fun fix i lift auto trans by myself on\off trans jack)

actually that was my last maxima(wht,92'gxe auto)you know you want one ha ha
when i had it at n.w.max.spring meet it was running.... barely
it was ****ed up ..the timey belt was too loose and moved teeth...danger,danger,but i fixed\reset belt before i sold it
other wise a good first max now sportin (91'se 5-sp.)still vg....
less horse powah,a lot less wieght since i have no airbags,abs,other

 

WHAT?! LOL

 

That was a little tough to understand...

I though you had a car that was a VE that had everything OK but the engine? I thought Spipedong90 inquired about it, but you said the body was rough?

Maybe that was someone else on NWMaxima...maybe MrGone can set me straight.

 

We are not sure if the cause of failure on my car (the motor we pulled out of it...portdave's etc.) was VTC or not. It appears that way but it could have easily been tensioner, chain etc. I have heard of others say that it was the VTCs causing engine failure but some time its hard to pinpoint the problem.

After doing it and seeing its not as hard as the bulletin made it appear I would go ahead and spend the $80 on the kit and whatever for the gaskets and get it done for security at least. I will probably do this for my 93 before I sale it. I obviously cant ground them and sell it like nothing is wrong and who would want to buy a car with a bad tick (except those of us that know what the problem is).

 

yeah, portdave's car did have a broken VTC. The cap was shattered and so was the timing chain cover. Like Michael said, we dont know if the broken cap caused the problems or was the result of other stuff happening.

just finished replacing my VTCs with some rebuilt ones two days ago

 

Nice work Craig! VE Powa

 

I know

 

I have a 94 se and the vtc problem was "supposed" to be fixed in 94. My vtc's only click when it first starts up and the engine is cold. It sounds like a nasty rattle and it only lasts for a couple of seconds. The good thing is that it doesn't seem to be getting any worse.

 

Are you using a high/good quality oil filter? Try using the Mobil 1 filter (m1-208) at least once to see if its your lifters making the noise.

 

ya hopefully the problem was fixed in 94 because I got a 94 jdm ve in mine and they VTC work fine, no clacking at all, no matter what temp. What is this mobil 1 filter? I thought the yota filter was the choice for VE? if using this mobil 1 filter and you hear clicking sounds, does that mean you have bad lifters?

 

I just finished repairing my VTCs yesterday! My car is so quiet, I can hear the injectors clicking. I love my car now.

 

Awe...thats awesome Arron, did you replace the upper tensioners while you were in there? I'm interested in some possible track gains for you.

Yeah, I was also so surpised at the injector noise and normal chain noises. But all in all, with the hood closed she purrrrrs.

 

There is no doubt about it... I gained a decent amount of low end power. BUT, I replaced an injector that was going bad, put in a variable intake system from a VE 5spd, put in a 63.5mm bored throttle body, lengthened my intake paths by making 1/4" intake and TB teflon spacers. I am pretty sure, the spacers made the difference. But it's too hard to tell since I did all that other stuff in the meantime.

But, I will be hitting the track very soon after I weigh 2930lbs and have my car perfectly tuned with race fuel with the ZEMulator and light rear skinnies on the car.

 

Excellent.....Muhahahahaa

 

The longer runners made the low end difference.