johnny blaze

well i bought a miata the other day, its a 91 with 119k miles, it ran great, and still does, but the oil pressure needle moves as you rev it up, idk if its suppose to be like that, and when i beat on it and drift it kinda hard and then turn it off, when i start it back up it sounds like a rod is knocking, but ill shut the car off, then turn back on later and it stops, if i baby her, wich ive been doing, it wont make the knock noise ever.... idk is my motor screwed? lol i cant drop it and rebuild or swap it at the moment, its my daily driven car, so just wondering if theres any tips im new to the miatas, i build hondas and this is my first miata ive ever even sat in.. thanks in advance

RedTurboMiata

the oil pressure gauge is normal, the 89-93 miatas had a real oil pressure gauge where as most cars have a idiot gauge that tells you you do or do not have pressure.

on the motor does it tick or actually knock?

Track

sounds like lifter clatter really. You might want to take a video with good audio in it. lift knock has a distinct sound compared to lifter clatter, but I don't know. I don't have HLAs, so I wouldn't even be a good judge.

If you were getting knock from abuse, you would be posting a engine rebuild thread after 2-3 times, especially if the knock is happening under heavy load (ie apparently you drift).

RedTurboMiata

thats what i was thinking so i asked what type of sound it was.

johnny blaze

the first turn over from the last time on while beating on it, its like a drum roll, it starts off fast and some what loud, then it slows down as the idle sets, then it just goes away, and i rev up the motor to see if it will keep knocking but it doesnt, ive had my fair share of spun bearings, once its knocking it will keep knocking, and reving it up just makes the knock so much louder and obvious, today it made a small knocking noise at cold start, but ive been driving it all day, turned it off and on several times, and its been sounding fine, and it runs great, oil looks good on the dip stick, the other day it sounded like the knock was coming from the head... but idk much im learning as i go, and hopfully this motor doesnt blow on me... lol

Track

yea that seals the deal, its not knock, its just HLA clatter. look it up and consider the options for cleaning your HLAs.

RedTurboMiata

This ^

its not much to worry about, if you stress the little rattles and such they can be cleaned. but letting them be wont hurt your motor, throw a little heavy oil in it and it helps in most cases.

johnny blaze

sounds good, thanks for the help guys, i went to town on the streets last night before i got home lol, when i woke up this morning it did the noise again, but it goes away right away, how do i clean that out? and im planning on changing the oil to 10w 30 mobil 1 is what i use for all my cars, i wanna keep this motor stock until i build a boosted motor, but i would like to beat the crap out of it in the mean time, lmao, im having way to much fun with the car, im glad i got it, surprisingly for how little hp this motor puts out it gets sideways pretty damn easy, and its easily controllable, my old s2000 use to get down but it was hard to handle it sideways... thanks again guys

RedTurboMiata

here is the link to a page with instructions on how to clean them. dont get yourself arrested lol
http://www.miata.net/garage/hla/cleaning.html