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Discussion Starter #1
Okay, I'll start here. I drive my 91 n/a maybe only 3k miles during the summer, and store during the winter, has 127k miles, have done 120k maintanence. 2 years ago, started to hear a strange sound from the motor, not the valve tick, or lifter tick thats so common, but something like a bearing.

I took to nissan dealer, and they said it was probably a rod bearing, or wristpin. I figured I'd drive it untill it quit, then put jdm engine in. But the sound hasn't gotten worse, and the performance hasn't dropped.

Z1 motorsports says it could be a vtc gear, and rod bearing would have spun by now. Z1 is in georgia, I was wondering if anyone nearby could recommend someone closer to check it out for me.

Any suggestions as to what the sound may be, or any help would be great, thanks........
Brian.
 

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You're a lucky man if you live in Ohio. Contact SilverTwinOH from here on the forum. He is very skilled with the Z32 and lives somewhere in Ohio.
 

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Member SilvertwinOH lives in Wilmington, OH and if you want to take the drive I'm sure he could check it out for you. He definitely knows his stuff around these cars better than any Nissan dealership would
 

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I would almost bet money on it being vtc springs. Thats what they sound like. Mine drove me nuts, then after I had SilverTwin do the 120k on it the noise stopped. They should have been changed when you had 120k service done. But maybe they didnt. Anyway SilverTwin would be you best bet on figuring it out and correcting.
 

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Discussion Starter #11
I've read a little about these vtc springs, but know very little about what they do. Is it a top end noise, that it makes, and just to be clear, it's different than the valve tick correct?

I know for sure that the vtc springs weren't replaced for the 120k maintenance. What noise do these bad springs create? And how does one go about changing them, cost, and labor wise whats involved. Silvertwin, I think it'd be about 4 or 5 hours, but I would definately take you up on the offer if you'd be willing to give it a look for me. Maybe sometime this spring i could drive it down.
 

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Hey Pulse,

I think I got the same sound and was told it was the VTC springs as well. Does it sound like a grinding type noise around 2000 - 2500 rpm and only when the car is in gear? This sound is driving me nuts too. I also have no performance drops. The car runs great other than that sound.



Post Edited (Jan 27, 2:46pm)
 

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It's pretty easy to get to the spring on the driver's side. Why don't you trying changing that one and see if you notice a change in the sound?

I'd first benchmark using an assistant to rev the car while I listened to each VTC Cam using a short length of rubber garden hose from outside of the t-belt covers. Hose helps to pinpoint sounds - much like a stethescope.

We can post of pix of the area - very easy to get at, front of engine jabove silver coolant pipe (line) behind the radiator.



Post Edited (Jan 27, 5:43pm)
 

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Discussion Starter #14
It sounds like a rapping sound when the car is revved around 3k rpm. Not grinding, or tapping, but a rapping sound, like something is slapping around. But no performance drop, no burnt oil, nothing. Could someone post some pics of where I need to listen. Should I just use a length of hose and place one end on my ear, and the other on the car?
 

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Here ya go...

VTC CAMS are just behind the bump outs in those black plastic covers -- follow my purple arrows.


Yes, while engine is running (parked safely - brake on, etc) -- use a short length (3ft or so) of hose to listen to those areas and see if that's where the sound is coming from. If not, trying using hose around other areas of the engine to pin it down.

Use common sense since engine is running -- don't stick hand near spinnig fan blade or belts.

Make sense?
 

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Discussion Starter #16
Makes sense, thanks. If these springs are whats bad, what physically makes the noise. Is it something bumping up against the cam?
 

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Sorry - not really sure? Haven't run into this on my Z (yet)!
 
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