1G knocking that goes away

[rtincher22085]

Ok I have a rebuilt engine maybe I did something wrong or the machine shop did. My oil clearances are 0.003 mains and rods .20 over JE/Eagle setup polished/balanced crank. it start it cold and you hear a knocking that appears after 5-6 seconds of idling then goes away when my car is at operating temp. sounds like its in the oil pan but also in the cams too. I know JE pistons are common for piston slap. The sound is in cylinder 4 for sure. I am boggled at that it vanishes and there isn't any metal shavings in my oil I have std size ACL race series rod bearings and std size King mains. I'll post a video of a cold start then a video of it warmed up after driving it If need be. I am hoping some one can share their knowledge with me on this issue.

 

[dsmpat95]

Mine made a knocking sound when its cold out. Mine is just piston slap.

 

[donniekak]

If you want peace of mine pull the rod caps to verify it's not knocking. I would think it's just piston slap if it continues to make the sound when cold, and survive wot.

 

[rtincher22085]

I was starting to think my pistons were to loose it sounds factory after warmed up . takes a while just idling I drive it a 10 minutes and its gone. that sound normal?

If you want peace of mine pull the rod caps to verify it's not knocking. I would think it's just piston slap if it continues to make the sound when cold, and survive wot.

It has survived a 7500 rpm pull and it pulled hard and no knocking afterwards.
I have already did that once thats why I changed to ACL race series because I thought it was rod knock first and its still doing it.

 

[bjones18]

Interesting info. Do you remember your ring gaps? and is the noise only at idle?

 

[rtincher22085]

The top ring .19 second is .22 oil rings are .28 noise at idle and. Under a load bit quiets a ton after warmed up to operating temp

 

[dsm_92_fwd]

well if you get to the point of a tear down ide check the wrist pins... could have bent one, BUT that doesnt substitute knocking only on cold start up. My old 1992 F150 did this too, ran perfect but kinda embarrassing to start up in public .

 

[Carlz0r]

I'd honestly be willing to bet that it's piston slap. Everyone that I know with JE's has it when they cold-start the engine. I have JE's in my new block and I'm sure they'll do it too. As long as you're easy on the engine while it warms up it shouldn't be an issue. The video will definitely help in diagnosing it though.

 

[deviousgst]

whats your oil pressure?

 

[rtincher22085]

On cold its 60+ warm idling is 20+ idling in gear is 8-10 psi

 

[deviousgst]

i dont think thats normal at all..

does anyone have any input on this?

have u dropped ## oil pan and checked for play on rods?

 

[92nolatist]

Im interested in finding out about this also. Mine is doing the same thing except I have manley pistons.

 

[1whitegsx]

What happened to this thread?? I have the same issue but I have .020" over ross pistons. The car ran great all year last year and now it makes a knocking noise like that but it doesn't go away all the way, it just gets quieter as I drive it. Ive been paranoid ripping my hair out over this noise but the car seems to run fine. I don't get how this happened out of no where. Should I be thinking about tearing the engine down and putting new pistons in?

 

[Cold Chill]

A friend of mine has a 3000 GT VR4 and he had some Ross forged alluminum pistons in and they told him his would nock till it warmed up. He said they told him that as the pistons warmed up that the alluminum swelled quiet a bit till they seated in. Sounds normal but theres only one way to be sure.

 

[1whitegsx]

Yea I don't know. I know they slap but it doesn't go away. I was also wondering if anyone has had an issue with their tension or Kevlar timing belt making a noise like that. I'm just trying to figure this out so I can go racing. Haha. I thought I spun a bearing so I've actually already put bearings in and then I was thinking it was in the top end so I put lifters in it because that's the only thing that isn't newer in the head. Compression and leak down are good. This noise is kind of embarrassing.