i hope i havn't worn out my welcome here, but i am still a noob with this car.
I have a pretty loud tap coming from right under the plenum. i did search on this topic for a good bit, but all threads on it said bent valves, bad lifters, or bad springs or something of the sort. but, i just replaced my heads with all new valves about 1,500 miles ago. it has run GREAT up until a day or two ago. the sound is pretty loud at idle, but i don't hear it much over about 2500rmp. when the engine is reved, it sounds a little like a hiss (this is a N/A). i know the timing belt is fine. it's brand new. The ECU is reading a 34, and i have heard that detonation sounds like marbles in the intake. any chance this is detonation?

 

Not at idle.

 

maybe blew the plenum -> intake man. gasket?

 

May seem really simple, but check your oil level.

 

yea i keep a good eye on the oil. intake sounds a little likely, but it runs so well right now. and the sound really is more audible while i'm accelerating, and barely at all or maybe not at all at idle. i'm still wondering about detonation too

 

I'm gonna have to agree with this one. Order a new gasket, pull the plenum, replace, see if that solves it. If it doesn't, at least the gasket was cheap.

 

i guess i'll give it a try. thanks. glad to see that you're back.

 

I'm never really gone... I just go in spurts when it comes to posting. I get tired of arguing the same bullsh*t on 3 different forums, so I give up occasionally - if someone wants to f*ck up their car, it's not my problem.

 

yea i see. what's your 3rd forum? i saw you on tt.net but what's this other one? i'm curious because i'd always like to find an additional forum

 

i think its like 300zx club or w/e

unless he means chicagoZ but thats for use IL people


speaking of which, i want spring/summer so i can go to a meet with both my Z's now. lol.

 

wow. still in college right? that's pretty impressive to have 2 z's while you're in college. i doubt i'll have any. i think i have to sell mine

 

well the tapping has gone away. but the hissing sound is still there. does it still sound like the intake gasket? i thought maybe an exhuast leak. i can't tell where on the engine it's coming from. it's not very loud. but it's still very noticeable while accelerating. and worse under hard acceleration

 

hissing is usually a vacume leak, so could be that gasket. could just be a line.

and yea im finishing up my full resto on the 280Z i just got and the turbo 260Z i might paint. but its just for power and fun. the 280 is the resto and good handling car.

 

I still think it's the gasket. It could also be a dumb mistake that I've made a couple times concerning the balance tube - make sure the metal bracket that shares bolts/bolt holes with the balance tube (I think on the passenger side) is not between the balance tube and the plenum - the bracket should be on top of the balance tube. Having it installed wrong will create an air leak that could make that sound.

And the third Z forum is ChicagoZ. I don't deal with 3ZC anymore - of all the forums, they have the lowest collective IQ I've witnessed. Can't argue logically with people who don't understand logic.

 

dont that before to... but noticed it before i started the car.

as for logic, i hate logic, when it comes to philosophy and its logic.... hate it.

 

I hope you're being sarcastic... without logic, we'd never be able to figure anything out. There'd be no science (which is founded in logic), and thus there would be no technology (such as our cars).

And btw, Philosophy was my minor.

 

i thought so, you have the talk sometimes. lol. i like logic, i just dont like how philosophy breaks it down so strictly. i have an entire packet on logic! lol. i never knew till this class that there were rules to logic. i prefered the, what makes sense and has support is probably true idea, after that class i disliked it. everything was either logos or ethos, deductive or inductive, disjunctive, then all had moods depending on middle term whether its the subject of both premises, and the predicate placement, then if its valid or not. and then the fallacies....

i hate logic in philosophy....

i enjoyed the rest, learning about thales, aniximander, aniximanes, soren kierkegard, heraclitus, pythagorus, plato, socrates, aristotle, sophism, metaphysics, epistemology, D'spinoza, Berkeley, cosmology, rationalism and empiricism werent that fun, Hume, epiphenomonalism, and behavorism. all better than logic. lol.

 

I'm rather disturbed that you'd include sophistry in that list... sophistry is almost the opposite of what [good] philosophers do: it's making a weak argument appear stronger than it is using tools of rhetoric. Philosophers argue in logic, which tends to be irrefutable, while sophist use language to make their false argument seem true. One of the charges brought against Socrates that ultimately led to his execution was that of sophistry... it's not a good thing. lol

And you knew of the rules to logic, you just may not have known that you knew them (a lot of it is very intuitive). Clearly if you know, A->B, and A is true, then B must be true. If you've ever had someone say "if you mow the lawn, then I'll pay you $10" and you mowed the lawn expecting that money, you knew what the statement implied. What most people have trouble with is proof by contradiction and the more complicated proofs where you assume a dozen things. Seriously though, I'm glad to see that non-philosophy-grounded people take that class - there'd be much less spoken bullsh*t in the world if everyone were required to.

And, I'm sure they were typos, but it's Anaximenes, Anaximander, and Kirkegaard.

And way to drag this thread off topic. =p

 

yeah, about that off-topicness.... i could say more, but i agree off topic. back on now....


curious, did you do anything that may have stopped the noise or did you just keep driving it and it eventually went away? got a VAC testing guage by chance? you should hook one up and get a reading. they are pretty helpful for as simple as they are.

edit: aww hell, i gotta, logic in the sense that A=>B if B is true A is and the other "formulas" similare to that one was the easy part of logic. it was getting those three sentance problems where you have to re-arrange the wording to follow proper predicate placement, determine which each sentence is (such as the E I O U or w/e they were on the logic square lol) then just... yeah i think you know what i mean. you have to find out if its valid then in what means ans so on.... i just didnt like tearing them down like that. if i had my packet still i could elaborate more on it but i seem to have lossed it..... also, those were typo's, and sophists were dumb, but it was still interesting. but i do like the idea of argument for the means of making something true just because i enjoy arguing. lol. and i think philosophy was actually a requirement at my college, but i still enjoyed it for the most part. never understood why me training to be a pilot needed philosophy though, same with theology.... ick.... guess thats what you get to going to a catholic/lasalian college.

 

i don't think i did anything to stop it. it pretty much just went away (the loud tapping noise). i'm under the impression that it was one of the plastic covers on the front of the engine. the hiss remains. tomarow i plan to re-torque the intake. this is because i didn't have the torque settings on hand when i did it and i forgot to go back and do it! my dad just pointed this out lol. so i'll post back when i find out if the re-torque helps that sound.

on the forum topic: i also follow zcar.com. i like it a lot. there are a LOT more threads posted reguarly then on this one. good ones too.

 

I don't like the layout of zcar... that was the reason I stopped going there.

And be careful not to overtorque the plenum bolts - it's soft aluminum and will strip easily.

 

i don't like the layout much either. but there are just so many people there. i guess it's great for me because i'm asking the questions not answering them lol.

yea i think i found the factory torque settings. thanks

 

is it just a TAP or a tapping that increases and decreases with acceleration.... What kind of oil are you running? Also... just because the valves are new, doesnt mean something wasnt done wrong... timing belt could have been installed incorrectly.

My NA had valve tick for about a week... then it stopped... im gonna be tearing apart the engine in the next couple months... so I'll be able to (hopefully) figure out what is worn out and could possibly been causing the tick.... Its possibly your valves are slighly out of adjustment....

 

the ticking is sort of intermittent. i think it is from the front of the engine when it does happen. by pushing on top of the engine (front cover, or top of valve cover) the pitch of the tick changes. it may be a valve or something but i'm not going into it again for a while that's for sure. i tried to crank down on the plenum bolts again and they were as tight as i cared to get them. i guess the gasket job is due. i did use one of the cheapest gasket kits so i could believe if it has blown.

 

"buy cheap, buy twice"

How many times do I have to say it?