bigman

iTrader: (1)

I think i spun a rod bearing. I purchased the car with 80,000 miles on it and the oil pre3ssure has always been around 15-20 psi. Well recently i have purchased a longer oil filter and the pressure stays at a consistant 20 psi when hot, around 40 psi when cool. Sometimes though when really hot, the needle bounces up and down. Also, recently i have had a tapping/pebbles/air rushing sound at idle and when i get on it. What do you guys think it could be? Thanks.

Cal

iTrader: (1)

Is the tapping sound at camshaft frequency, or crank frequency? Cam turns at half the crank rpm, so if valvetrain related it will be a slow tap. Fast tap is a rod bearing. Also, if the sound gets lounder with the engine under load, it's a rod bearing. If you've ever heard a lifter that doesn't pump up well, you know the slow tap.

SUX2BU

iTrader: (14)

if you spun a bearing you weould know right away. KNOCK KNOCK KNOCK

TheBowtieboy

iTrader: (6)

I have had a spun bearing, and trust me, you'll know when you have one.
........I just lightly spun one and it was still very loud and distinctive.

Now, after my rebuild, I was very careful about the break in of the engine. After putting the miles needed on it, I had it dynoed; now I too have very good pressure cold but falls to 25-30 PSI warm/hot at idle with "bouncing" occurring every once in a while from 15-25, still fine under acceleration.
I am of the opinion that the lifter(s) is/are the problem. I used my originals, as they still looked good, but believe the added HP and RPM's might have caused a problem......I know, I should have went ahead and dropped in new ones

Good luck !