The Z has developed a tick, and wondering if I exacerbated the cause with FI or an over-rev...

I can pinpoint it to an engine noise and not drivetrain/clutch: the noise is consistant with the rev of the motor, either clutch in or clutch out. The noise is cyclic as such: "ti-tic-tick-tick-tick....(1½ second silence)...ti-tic-tick-tick-tick....(1½ second silence)... *repeat* "

Not loud by any means, but the loudness of the ticking increases as the # of ticks progress, then completely ceases for 1 and 1/2 seconds, then repeats. I can hear the sound *better* from under the car, but then again the valvetrain is noisy up top, so no real help there. The front pulley is VERY wobbly, and I have some oil dumping from the front seal, but oil levels have been closely monitored and always around 5 - 5½ qts.

Happens cold or warm. This is a recent sound, within the past couple weeks I imagine... running Mobil synth. 10-30, religious about oil changes.

I figure if it were a rod, the noise would not be variable. So... maybe something in the valvetrain? Timing chain? Crank pulley? Been searching the site the greater part of the morning trying to discern the likelyhood of major engine drama...

Any help is appreciated - TIA!

EDIT: The *silence* interval is at idle; interval decreases as RPMs increase, but there is an interval nonetheless

 

i would use a mechanics stethoscope. you can pinpoint sounds pretty easy with it and sometimes tell the depth if used in different areas around the noise. they have pinpointed many previous noises for me on other cars.

 

Does the sound noticeably get louder as you get into boost? Any power loss, smoke, any other signs besides the sound?

I went through two blown motors, unfortunately, you can drive yourself crazy trying to diagnose the issue based off of sounds, smoke colors, etc...
Could be a variety of things (like you had listed)...

let me know if you'd like to go the route that we had discussed...I think the swap will be very convenient per our locations
Good luck, let us know if we can help.

TODD

 

May have to pursue the stethascope method...

The noise doesn't get louder going into boost, but the cycle of the ticking increases with RPMS (if that makes sense). No power loss, no smoke, no odor, no change in AFR, no driveability changes... i'm slowly driving myself crazy with the 'What If's"

It's likely I'll end up going the route we discussed, tho I may, for cost considerations, tone down one or two items since I'm not going *****-out on a rebuild :lol: Trying to work out in my head whether to swap myself since I'm intimately familiar with the APS installation, or have a shop give it a whirl Gotta finish up the closing on this second house, too, which is soon.

In any case, I'll continue to drive her, and look into replacing that CP next week or so. Any other sound suggestions are appreciated

 

i hate to put a scare in ya, but the cycle you are saying could be a rod bearing. goes quite for a sec when under pressure then comes back during the other cycles. just guessing, i would obviously need to hear for myself to tell. if your timeline is exact to the noise, i would doubt that to be the prob though.

 

Hmm - would you suggest pulling the harness to the coil while running to each cylinder (as suggested in another thread), thus failing to fire and initiate compression... in hopes of finding the 'broke' cylinder? I get a little iffy about reaching for high-amp stuff when its running, ya know? LOL

 

change that leakin pulley !! i found mine got a crack from inside ..

 

Spoon!!

 

WAIT!

Did you say the crank pulley is wobbling?!?!? I had that same problem with the same sound.

I was running a UR pulley for a while and then I noticed last summer that it was wobbling. Obviously, that is a huge problem. So, I dismounted the pulley. The first issue was that the bolt holding the pulley to the crank was insanely loose. Second, the keyway on the pulley itself had gone from 3/8" to well over an inch (the wobble action progressively elongated the keyway on the pulley, not the crank).

The end result was that the pulley was trashed. I just put my stock one back on and that fixed it. The stock pulley fit tight and ran true. Thankfully, I did not blow the front oil seal.

If you did blow the front oil seal or just want to be safe, they are cheap and easy to replace. Just consult the factory service manual. If you already have the pulley off, it is a good time to replace the seal.

By the way, if you are unsure what the cause it, at least examine the pulley. It is an easy check and worth it if it is wobbling. As a side note, I am not F/I. I don't know why the pulley went, but I think it was because the bolt got loose first.

 

You've given me some hope Fluidampr pulley ordered and I'll keep everyone updated as to whether this resolves/diminishes the sound...

 

I never really understood why people bothered with pulleys, as it always seems to end with something like this. I'll cross my fingers for you and hope it's just that and not a rod-bearing.

 

I need to bother with it because it's lookig as tho it's going to fly off, might as well stave off future trauma - and on a hope and a fart that it resolves my noise. My luck - it wont, but it'll be one less issue I have to address down the road (the pulley) until I decide how to pursue a d*cked-up rod bearing

 

um, this is the second time I read of a wobbley pulley so I don't know where you get "this happens all the time." Keep in mind that I read about both wobbley pulleys in the same thread......this one.

 

Bro..something is wrong....I bet you misshifted huh....read my thread...I did the same thing...https://my350z.com/forum/forced-induction/175137-i-m-building.html Anyways your crankpully is def cracked...that is why oil is coming out but your oil level isn't changing much..same thing happened to me...I changed the crank pully..then the ***** blew up...so I'd build now before it blows a hole through the block..call sharif at forged internals tell him big bri sent you..

 

I did mis-shift - thought I mentioned it in this thread but didn't... pulled a 3-2 mis-shift at 94mph... *sigh* THREE TIMES IN ONE WEEK!

I deserve it, and that's OK - I'm not one to mis-shift, and I usually at folks that do - such is life.

That's why I think the ticking is symptomatic of a more serious-to-come problem. Now I need to plan for either a stock transplant or just suck it up and go Forged, ya know? Maybe I'll luck out - but I'll plan for the worst...

EDIT: Just read your thread - dumb luck, eh?

 

damn, good luck, hope it isnt anything too serious.

 

Yea...3 times ***..you stock or F/I...you figure it takes 3 times stock but when your pushing as much power as me and you misshift once your Fuked...Anyways good luck go forged its almost same price as stock...

 

Well - current output with APS ST is 437 rwhp/446tq with 14psi peak, so... yeah...

Blah!

Will keep everyone updated - pulley expected to arrive Mon

 

Interesting noise..Normally a Valve train noise is a noticable steady "TAP" whereas a rod bearing is a louder "slap" sound.Keep us posted on your findings.

 

crap.. i am getting the same 'tick' or 'slap' noises too. guess i will have to check my crank pulley as well.