Slight knock at low oil pressure?

OK, here is an oddity. I am pretty sure it is a rod journal bearing getting unhappy after a season of drag racing w/ a ZEX kit on it, but wanted to run this by some of you.

My 90 rs drag car got pressed into service for daily use after my Accord went nose to tail on a Sentra. Anyway, when I drive the car for about an hour, whether in traffic or normal cruising speed on the freeway, when I come to a stop, you can hear a SLIGHT knocking sound from the bottom end. At this time, the oil pressure reads about 14psi @ 800rpm. Is this oil pressure reading normal for the RPM? If you goose the gas pedal a bit, it’ll go up to 20’s in the PSI range, and then slowly drop down, but the sound is still there.

OK, the odd thing. Turn off the car, wait 10 mins, start it back up. The knock sound is gone. The oil pressure reads about 24 psi @ 800 rpm now. I figure the higher oil pressure is keeping the rod bearing happily oiled.

Is this normal? Is there a way to keep the oil pressure at 20 psi minimum at idle? Does any of this make sense, or has my brain lost it again?

Oh, and the oil used is Mobil 1 10w30 full synthetic w/ a Honda OEM filter. I was used Castrol 10w30 sythentic blend before but didn’t notice the sound then or it didn’t occur. Ideas?
Thanks.

bump. Anyone?

it sounds low to me maybe your oil pump is going

is your oil light on

My vote is for the all to typical rod bearing. After goign round and round with vern’s car, when he pulled the engine it was the rod bearing

hot the oil presure should be at 10 psi hot at 3000 rpms it should be at 50 psi. maybe you should go to a thicker oil how may miles u have on it. hope this helps

get a gsr or a typer oil pump it would be better

Thanks for the replies. To answer the questions:

  1. oil light is not on.

  2. at 3000rpm pressure usually sits at 60psi +/- about 5psi , so I’m sure that is ok, which kinda rules out the oil pump.

  3. I’m betting the rod bearing, too. A full season of drag racing pulling 13.9 passes may of taken it’s toll.

No sense in rebuilding it, I got other engines to put in its place. Thanks for the replies. Looks like it is B18b swap time, unless I put in the B20 :slight_smile:

B20 is a great bet… what engine is this hurt one? a b18 or b17?

It is a b18a w/ b18b head. I think it was rebuilt about 50-60k miles ago. I don’t know for sure, no one is sure at all. It eats about 1qt of oil every 1,000mi due to all the high RPM driving on the highway I do (JDM S1 tranny), so it gets changed regularly; usually sits about 4,000rpm. I think the rebuild wasn’t too good on the ring seating b/c the oil turns black in a short time, so stuff is slipping by.

I get a noise at startup, any startup where the car was sitting for more than 4 hours or so, that I think may be a rod bearing, it will make a loud clicking noise until the oil pressure light goes off, then instantly it stops making noise and purrs like a kitten. A rod bearing is the only thing I think it could be, but is that cause for concern/replacing the engine?

Anyone know if what im describing sounds like a rob bearing? I can make it do it less by putting in a little thicker oil, and it actually seems to do it less, or not at all the colder it is (the thicker the oil im thinking). But after startup there is no problems that I can tell.