98 civic .. Disappearing knock/tap

[onesikEJ8]

whats up guys, i tried to find anything that I am experiencing and I cannot find anything. My y8 hydrolocked, so I got a new motor, I put it in, and it is knocking/tapping, but after warming up a little bit, it gets quieter, and even goes away sometimes. Also, the noise changes tone at times.

I am afraid its a knock, but any other ideas, and possibly a fix with lucas oil stabilizer? ughhhh

thanks ahead ..

kyle

 

[Avant Uprising]

might pull the valve cover and check for blockage also u should put a anti drain back filter to get oil to the head faster and the oil pump might be getting weak

 

[sr6000]

While you have the valve cover off might want to check the calve lash

 

[96romaCX]

I was having this problem also, I put a bottle of marvel mystery oil in and it went away, but I know it didn't "fix" anything. I also thought it was valve lash but had someone fell me it was a bearing about to go.

 

[Jermee]

Umm.. Do a compression test.

 

[onesikEJ8]

tomorrow i will be resetting the timing, checking compression and the valve lash .. i hope this is simple "/

 

[00siboy]

Sounds like piston slap. Does the frequency change with the rpm? Does it come and go when you snap the throttle at idle?

 

[onesikEJ8]

i guess you could say that .. there are instances where if i leave it idling, sometimes it just stays quiet, if it was actually a rod knock i would think the noise would be constantly regardless

 

[onesikEJ8]

i would think the noise would go away if it was piston slap considering that pistons will expand with heat

 

[onesikEJ8]

i just checked compression .. 175-180-180-175

 

[96romaCX]

Sounds like piston slap. Does the frequency change with the rpm? Does it come and go when you snap the throttle at idle?

Mine does, it doesn't knock under load it just sounds rough at 2500-3000 rpm

 

[00siboy]

i just checked compression .. 175-180-180-175

Unfortunately its pretty difficult to go any further with this online. You are either going to have to tear it apart and have it checked out or find someone knowledgeable who can look at it.

 

[onesikEJ8]

yeah youre right .. im just not sure what i want to do, just find a for sure known good block or what.. swap out my old oil pump .. ughh this is frustrating

 

[00siboy]

Not as frustrating as a 8k mile b16 that burns oil worse than before the rebuild...

 

[onesikEJ8]

i can only imagine ..

so i just hooked up a oil pressure gauge .. got the engine to normal operating temp .. let the fan go on twice, at idle oil pressure is between 5-9 psi (not quite 10) and at 3k its under 40 psi

im really thinking its the oil pump

also, i checked the valves, about 4 valves were perfect, the other 12 were either so tight that i couldnt fit the feeler gauge in or a little loose.

 

[00siboy]

Should be around 20 minimum at idle. If its a pretty high mileage pump it sounds like it could be the problem.

 

[onesikEJ8]

i thought the honda service manual said 10 at minimum at idle, and 50 minimum at 3k .. tomorrow or tuesday i will be swapping oil pumps since i have one that is known to be good

 

[00siboy]

If Honda says so then its probably right, 20 just seems to be what I see most of the time on cars in general. So does that mean you are a little low at idle and really low at 3k?

 

[onesikEJ8]

well it says 10 minimum, so 20 would be healthy haha .. but it fluctuates between 5-9 psi .. then yeah at 3k its far below the 50 psi mark