Place you bets: Rod knock or an Imposter

[IwantMKIII]

It appears i've developed quite the knocking noise in the bay area again. Now for those of you who don't know or remember I got this last year thinking it was rod knock but turned out to be POS OBX adjustable gears causing the noise.This time however stock gears are in place. Keep in mind this is still a young engine with between 10-15K miles. It was run low on oil once over a year and a half ago breifly do to a front main seal leak.

What i know so far:

NEW: heard with stethoscope, low,out of spec oil pressure (25psi at 3000rpm)
*RPM dependent
*If it IS rod knock its only slight and bearing is still intact
*towards the front of the engine (Cylander 1,2, crank area), just like last time
*Hard to hear as RPMs increase even slightly

List of things to check off the top of my head:
*All rotating assemblys, ie pulleys, are they loose? Especially crank pulley
*Cam gears (of course)
*Pull spark plugs to see if the knock goes away even a little.


I would post videos of the old knock but YOUTUBE has screwed up my videos and they have no sound now for some reason even though 6 months ago they were fine.

 

[black89t]

does it go away under a load? or does it happen at that rpm no matter what light throttle/wot?


those are key.

 

[IwantMKIII]

^engine becomes too loud to distinguish the noise from other things

 

[speedfreak426]

sound like this???
That is my video of my 7m celica, thought it was a knock.... it was actually piston slap and it had slight ridges in the bottoms of the cyl's

http://www.youtube.com/watch?v=KooOxJ38LhI

 

[ERA]

AIDz

 

[grimreaper]

swine flu

if you hear it right off idle and at idle as well im saying camshaft noise

 

[IwantMKIII]

sound like this???
That is my video of my 7m celica, thought it was a knock.... it was actually piston slap and it had slight ridges in the bottoms of the cyl's

hurl][/QUOTE] actually it does s...als next week so i've been reallyreally busy.

 

[IwantMKIII]

swine flu

if you hear it right off idle and at idle as well im saying camshaft noise

head was rebuilt during the rebuild. Not sure why it would do that. But the noise sound like it has some decent mass too it if you get what i'm saying. Not just a lifter hitting a valve hard, something larger like a hammer tapping very lightly

 

[Moy]

post up a video.

 

[IwantMKIII]

Well im afraid it may be.

On top of my mysterious trans problem things arn't looking good.

I can hear the knock in the area of cylinders 1 and 2. Very slight. Does not get louder with higher RPM which is strange. However i never noticed until the other day spec oil pressure calls for 36+PSI at 3000 PSi, mine is in the mid-20's which further suggests bearing issues. Its been in that range for awhile now i just never knew it was out of spec.

Ill know for sure in a week or two, if i can even get it home before my "mysterious trans issue" blows up in my face. It needs to last about 500 miles until i get home. Im scared.

 

[hvyman]

pull the no 1. plug wire and see if it goes away.

 

[Velocityfreak]

You say the head was rebuilt? was the head decked at any time to straiten the head at all? If so, and your head was slightly warped before the rebuild, that also means the cams are strait but the head is warped the deck now strait, but the head is still warped, you will have problems down the road, as the cams are strait, and the head is warped its putting a load on the cams via the bearing surfaces. One way to check is to pull the valve covers off and check the bearing condition around the cams, if theres alot of wear there and the head was just rebuilt, its time for a new head. But first:

Only true way to figure it out is get a stethoscope and find where the largest noise is, and work from there.

 

[gaboonviper85]

Snafu