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Wannbedrifter
02-27-2012, 09:04 PM
OK before you flame me, ive used the search button and i didnt find anyone with the same problem as me

i picked up a s14 with a s13 blacktop sr, previous owner ran high boost really high boost for some reason, it ran fine tho and i lowered the boost down to about 10psi, then i gave the car an oil change with mobil1 fully synthetic 10w30 (i live in new england in case youre curious) afterwards when i started the motor YOU DO NOT hear a knock at idle but when u give it a little gas you can clearly hear a knock, a very fast one, my tach does not work so im guessing the knock occurs at about 2k RPMS and goes away after 3k, i automatically assumed a spun bearing because of high boost but there are no metal shavings in the oil, next i thought it was a lifter or a rocker arm but my buddies sr20 that had a stuck lifter and faulty rocker arm you could hear the knock at idle

i am just curious if anyone has ever heard or has encountered this problem, any help/info would be highly appreciated, i dont want to THINK its a bearing order one, open the block and find out it isnt it -.-

copmagnet
02-28-2012, 05:47 AM
Throwout bearing? Mine starts making noise at about 3500 rpm's and drops off at 4000 or so. And it's only 2 years old. Guess I have to take the trans out again. Could be your problem as well.

nomoremk2
02-28-2012, 07:10 AM
Rod knock doesn't just disappear like you're describing. I doubt that's your problem although it's obvious something is wrong.

Wannbedrifter
02-28-2012, 05:50 PM
I also thought it was a throw out bearing because when i clutch in and clutch out it squeaks. this is my first nissan and my buddy that has been through about 6 of them told me that this is normal for nissans. also my other friend tried giving the car gas with the clutch in and with the clutch out, it still made a knocking sound inbetween 2-3k rpms. i forgot what he said but it was something along the lines of "if you clutch in and theres no knock its your throwout bearing" or vice versa i forget

nomoremk2
02-28-2012, 08:53 PM
Throwing bearing should be more of a whirring, almost howling wind noise. Not anything close to a rod knock. If you guys can't figure it out soon I'd take it to a shop. You could be playing with something that'll cost you alot to fix if not properly diagnosed.

Wannbedrifter
02-28-2012, 10:48 PM
I might consider taking it to a shop but I got a longblock sr on the side and I was thinking about blowing up this motor first event of the season lol

Nicelyphe
02-28-2012, 10:56 PM
I kind of have the same issue but don't worry much. Real deep, faint, low tone knock sound. Mine seems to do it underload between 1k-2k rpms, then that's it. Also usually only does it for some time, like after a half an hr of driving it doesn't do it anymore. Also depending on weather conditions. My throwout bearing makes a decently noticeable whirling at idle as well. Car doesn't run terrible or anything either.

S13 blacktop SR here, running 7 lbs.

Dark Spec
02-29-2012, 02:21 AM
maybe chain or chain tensioner making noise...