New motor knocking???

[Dennis197SD]

I recently installed a remanufactured 4.3 in my 06 bayliner 197sd... motor came from gearheads with a no fault warranty.. while testing on water after about 30 min I was running at 2800rpm and I noticed a slight change/ light hesitation in the way it was running as well as some light smoke coming from the valve cover hoses.... came back to an idle and the smoke stopped...I continued testing but noticed a knocking noise now but only at certain rpm ranges...I ran for an additional 1.5 hours with no change in noise...i moved the distributor to see if that affected the noise and it did not.. I also removed the lower unit in the driveway and ran to see if the noise went away but there was no change. Im gonna upload some videos and would like to see what you guys think....is this an internal engine issue? Is it possible it's something else? Any ideas would be appreciated. Thanks

 

[Dennis197SD]

Knock video

 

[Dennis197SD]

Knock video

 

[Dennis197SD]

Knock video

 

[Mcfltfyter]

Was the timing set correctly before you moved the distributor, and was it reset afterwards? The first video sounds like a lifter, but its nearly impossible to tell from a video.

 

[Dennis197SD]

Was the timing set correctly before you moved the distributor, and was it reset afterwards? The first video sounds like a lifter, but its nearly impossible to tell from a video.

Yes. I set it to 10° btc and put it back to that after seeing if that changed anything....a lifter outof adjustment would tap correct? It wouldnt be knocking unless the lifter itself was bad? I was gonna pull the valve covers and see what I found...I also noticed when I fired it up after work today it didn't make this noise until it ran for a good 5 or 10 min

 

[Scott06]

Lifter clearance will increase as engine warms up. I would take valve covers off and readjust rockers arm nuts. doesn‘t sound like crank or rod bearings to me . What do the spark plugs look like

 

[TMcDaniel]

I recently rebuilt my 4.3 and there is no lifter adjustment. Stupid question but did you put oil in it. Sounds like mine did before it blew up (bad oil leak and no oil). Also the lifters might have been dry from sitting after it was rebuilt and the just need time to get oil in them. I know it’s not fun but you might want to pull the heads off and check the lifters to see if the are firm or squishy.

 

[Dennis197SD]

So I pulled the valve covers last night and couldn't believe what I found... half of the pushrods had no oil coming out and the others were barely.... the insides of my covers are completely covered in what I think is assembly lube... I have 80psi of oil pressure so I'm thinking maybe the lifters are plugged or there's a blockage somewhere. I changed the oil and ran with no change.

 

[Dennis197SD]

Valve covers

 

[Dennis197SD]

Push rods

 

[Dennis197SD]

Knock

 

[Dennis197SD]

Lifter clearance will increase as engine warms up. I would take valve covers off and readjust rockers arm nuts. doesn‘t sound like crank or rod bearings to me . What do the spark plugs look like

There is no adjustment on these...I haven't pulled the plugs yet. They are a nightmare to access

 

[Dennis197SD]

I recently rebuilt my 4.3 and there is no lifter adjustment. Stupid question but did you put oil in it. Sounds like mine did before it blew up (bad oil leak and no oil). Also the lifters might have been dry from sitting after it was rebuilt and the just need time to get oil in them. I know it’s not fun but you might want to pull the heads off and check the lifters to see if the are firm or squishy.

Yes it does have oil... this motor literally only has a total maybe 4 hours of run time on it. Do you think a lifter would cause a knock like that without being damaged? Cause at this point I'm probably gonna just exercise my warranty. Im afraid if what's all damaged inside

 

[Lou C]

The older pre Vortecs had adjustable valve trains but that was changed to a net lash system (not sure of what year that changed) that’s not adjustable. However a defective lifter could still make noise. It also could be a timing chain with too much slack. I’d try removing the SERP belt just briefly when you hear the noise and see if it goes away. Wear in the bearings in idlers, tensioners alternators water pumps and power steering pumps can make noise, spin each pulley and see if they turn smoothly with no roughness.
Not related to your concern but I notice you have the one piece manifolds, these were only used about 3 years because they had trouble casting them and they can be prone to failure putting water in a cylinder. I had OMCs version of this design, never had a problem with them though, and converted to the 2 piece design when they were due for replacement.

 

[Lou C]

PS:

I did a top end overhaul on mine 4 years ago and engine noise was basically the same after the replacement of cylinder heads.
What you're calling assembly lube looks like water in the oil....I did a top end overhaul because I had 2 blown head gaskets due to an overheat 3 years prior, the water in the oil also will raise the oil pressure because water is more dense than water, the inside of my valve covers looked exactly like that.

if you pull the spark plugs and crank it over does any water come out of the cyls? If so it could be those one piece manifolds, I'd check that out before doing anything else. There are other tests to determine if your cooling system is not holding pressure and/or you have combustion gases leaking into the cooling water. Check the manifolds first then if they show signs of leaking dump them in the trash and get the Barr Marine conversion kit.

 

[TMcDaniel]

Lifters with no oil will make that noise. It is possible to not cause damage. After my rebuild I had very high oil pressure until the assembly line wore off and all the bearings seated or wore in. If you can get the lifters out try soaking them in oil overnight them test them. Push down on them if they squish easily they are bad if they are hard they’re good. Reinstall and see what it sounds like.

 

[Lou C]

Here's what mine looked like. Looking at your engine running, the oil itself doesn't look like it has water in it....but does assembly lube really look like that?

 

[tank1949]

I recently installed a remanufactured 4.3 in my 06 bayliner 197sd... motor came from gearheads with a no fault warranty.. while testing on water after about 30 min I was running at 2800rpm and I noticed a slight change/ light hesitation in the way it was running as well as some light smoke coming from the valve cover hoses.... came back to an idle and the smoke stopped...I continued testing but noticed a knocking noise now but only at certain rpm ranges...I ran for an additional 1.5 hours with no change in noise...i moved the distributor to see if that affected the noise and it did not.. I also removed the lower unit in the driveway and ran to see if the noise went away but there was no change. Im gonna upload some videos and would like to see what you guys think....is this an internal engine issue? Is it possible it's something else? Any ideas would be appreciated. Thanks

Did you prime oil pump motor before cranking? 80 psi???? Oil should be pouring off rocker arms. Something seems blocked! If you purchased motor local, perhaps you should have them examine it.

 

[Dennis197SD]

The only reason I don't see it coming from the manifolds is i never had any of this before putting this new motor in..

So I dropped the oil... this is it. 4 hours tops on this engine...I dont know if that's water or assembly lube making it like that but if it was water shouldn't I have increased oil level? And if it's watery why isn't it coming out of my my rods with 80psi?