Questions regarding oil pump failure

[elkaboom]

I've been noticing some faint, but distinct, bottom end tapping noises lately. Typically, at idle; sort of an intermittent wobbling type of noise -very faint (like a soft "clucking") if you follow me...
When I start the car and it's running at high idle, you can't hear it, but when it kicks down to normal idle, I'll hear it.
I'm wondering if this is oil pump/oil pressure related.
What are the telltale signs of oil pump failure prior to catastrophic engine failure or serious engine damage.
With all the little annoying problems I've been having lately, I'm curious.

[THAWA]

shit, my car sounds like that

[elkaboom]

Not to be an alarmist or anything, but I just got to thinking about it after reading WRXdans thread about his rod knock and possible bearing failure.
Granted, my noise is nowhere near as bad as the sound coming from his poor 'lil motor, but still... an ounce of prevention and all that.
Just to be anal I pulled the plugs and gave 'em a thorough inspection for a possible heads up on potential engine trouble, but the plugs (hehe, "buttplugs" ) were beautiful, light grey color on the terminal, no wear what so ever. Also, the electrodes and the insulators were pristine. I could have reused them (less than 15k miles), but I don't like reusing spark plugs after they've been out of the car.
Anyway, I'm gonna change the oil and filter tomorrow just to see what happens -kinda pisses me off to do so as I only have about 1k miles on five quarts of Redline and a new filter, but a man's gotta do what a man's gotta do I guess
Maybe I should start prefilling the filter...

[THAWA]

well it definartely doesnt sound like a rod bearing to me.

[94L_wagon]

Are you sure its not just the hydraulic lifters tapping?

If its a light clacking noise that'll be what it is. They all get a bit noisy sometimes, especially at idle. They make more of a light ticking rather the heavy knocking or clacking you'd expect from something more terminal like a bad rod bearing.

[entirelyturbo]

I have it too, and it may not be engine-related at all.

THAWA, remembering what transmission you have in your Legacy now, this doesn't apply to you.

I have heard some rumors of the front main bearing in the transmission in a 90 Legacy MT being good for about 120k miles. Granted mine is a 91, but who knows?

After a while, the clearance opens up and while no real serious damage occurs, there is a faint rattling sound toward the rear of the engine/front of the transmission.

I've had it for quite a while now, and I'm not going to worry about it unless a serious problem develops from it. The next time I do the clutch (and yes I do plan on keeping the car that long ), I'll probably be so brave as to crack the tranny case and attempt to replace the front main bearing on it.

Then again, this may not be your problem. Always check things like heatshields and stuff that may rattle and lead you to believe it's internal...

[THAWA]

I heard that aswell mike, but I thougth that bearing was in the rear of the tranny, I dunno, it doesnt sound like tranny noise, and it definately was there before I swapped trans's. Personally I know i doubt my sound is a heat shield. It juts sounds like a scraping, I dunno, I'll leave it be for a while.

[evolutionmovement]

I've heard this transmission noise and does resemble the rumble of rod bearings. It only happens very occasionally and goes away after a few seconds. I found out it was the transmission when I put the clutch in and it went away.

Steve