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First start!!!!!...5.0 swap...disturbing noises..need advice from engine guys.. Updated 3/8 with oil pan removed and video link

skrit

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A Horse with No Name
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Apr 24, 2006
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Durham
Amateur rebuilt Explorer 5.0 with rebuilt 4R70W done by me. Finally got my wiring all sorted out. The big night for first start.

Everything factory including exhaust manifolds, original good shape pistons cleaned with new rings, rebuilt valve train. Original cam and crank (polished and new bearings). Honed cylinders. New harmonic balancer. Tolerances in spec when I rebuilt it.

Primed the oil pump 2 weeks ago. I'm using Royal Purple break in oil. Took 3 cranking cycles to I get the fuel and oil flowing right. Fired right up!

But....very noticeable thudding knock sounds at idle at the block. Rev up to around 2000 can't hear it but it's loud so it might be masking it. This is a rolling chassis. Not a valve tick. Note: my exhaust is mocked up with crappy clamps and not complete. I can feel vibration on the engine block.

Would a video with sound help? I know I might have to pull the motor. Could be a spun bearing?

I have a Blue Driver Bluetooth scanner in the ODB2. No faults other than evap stuff I need to work out.
1000012756.jpg
 
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lars

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NorCal flatlands
Video with sound might help. So many possibilities. Loud exhaust doesn't help. Torque converter nuts tight to flexplate? Piston slap (unlikely but possible). Oil pickup tube not fastened to main bearing bolt and rattling around (yes, I've seen that)?
 
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skrit

skrit

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@lars You may be right. It sounds like it's coming from the rear of the block but sounds are deceiving. BTW, thanks for the reply! Ya'll let me know if the video is no good.

Here is also a link which I hope works: 939993-283b138428ddc0ca3dd522af2b83ac86.mp4

 
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noslo5o

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Oct 20, 2007
Messages
125
Sounds more like a rattle than a knock. I would give all the fasteners a once over and check to see if your missing any tools. A long screwdriver placed to your ear can act like a stethoscope to help you pinpoint the location.
 
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skrit

skrit

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Sounds more like a rattle than a knock. I would give all the fasteners a once over and check to see if your missing any tools. A long screwdriver placed to your ear can act like a stethoscope to help you pinpoint the location.
Well said sir. I know about the screwdriver trick. Could be a missing 10mm socket :p

I'll pull it apart next weekend but wanted to get a feel of what I should be looking for. Just afraid to run it for more than a minute listening for the exact location.
 
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skrit

skrit

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I just started it up again and it's definitely coming from the lower....

A while back when I was rebuilding... it was very hard to turn the crank with a torque wrench (i posted about this).... this has to be a reason
 

badandy73

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Could drop the pan and inspect/ investigate, especially if you think it's coming from the bottom end.

Hopefully it's something simple and you get it figured out... clean looking chassis BTW!
 

EPB72

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Pleasant Hill, CA
I just started it up again and it's definitely coming from the lower....

A while back when I was rebuilding... it was very hard to turn the crank with a torque wrench (i posted about this).... this has to be a reason
when turning crank was it just the crank or were the rods?pistons connected as well,,, just the crank you should be able to turn by hand,, and the pistons/rods were reinstalled in original locations ? just asking,,, btw the sound clip didnt work for me.
 
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skrit

skrit

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when turning crank was it just the crank or were the rods?pistons connected as well,,, just the crank you should be able to turn by hand,, and the pistons/rods were reinstalled in original locations ? just asking,,, btw the sound clip didnt work for me.
It turned easily by hand but once the pistons were in and the heads were on it became very tight.
 

spap

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I have had a flex plate gear ring semi separate from the flex plate, if it is a rattle . Yours sounds different though but never hurt to check
at least you don’t have the body on… even the new stufff is old stuff
 

DirtDonk

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Is the drive belt installed for the front accessories? If so, remove it temporarily just to eliminate separate items, as well as tension on the crank in one direction.

Are you checking for oil pressure? Do you have gauges connected?

Is there a driveshaft or at least the transfer case attached to the transmission?
Fluid in the transmission?
 

DirtDonk

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Ok, I see by pics your other thread that you have the drivetrain installed. So presumably the transmission is in park or neutral, or it might’ve been trying to drive through the wall! :)
 
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skrit

skrit

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I'm going to drop the oil pan and inspect. I'll update with my findings ASAP.

NOTE: I have yet to completely fill the tranny with fluid. Forgot to do that - focusing on the engine. Does the torque converter turn if it's not in gear? I'll fill it up this evening.
 

DirtDonk

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The torque converter is always turning with the engine.
Remember, the body of the torque converter is rigidly bolted to the flex plate. Which in turn is rigidly bolted to the crankshaft.
So yes, the external components, meaning the main body, is always turning.

What else turns, and does not turn, once it turns the input shaft of the transmission, I do not know.
 
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skrit

skrit

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Ok folks. I just got back from a family vacation and I'm back at it. I fired my engine up again but was armed with a stethoscope, a properly filled tranny, a mechanical oil pressure gauge and a working scan tool.

That loud banging/rattling sound was definitely coming from the oil pan area or lower block.

After letting it do it's thing for a minute, I was thinking that the PCM might just be working through the initial timings.

#1 cylinder timing started at 17 degrees and after 5 minutes was at 35 degrees for a while then down to 20 before I shut it down after 10 minutes of run time total.

Fuel pressure steady at 30-35 psi and oil pressure steady at 55-60psi.

The loud sounds eventually went away and it was purring. I had to stop the run test because my coolant temps were getting very high. I didn't bleed the cooling system and probably should have and may have gotten too much RTV on the thermostat making it stuck closed.

Would it be possible that all that noise was just the sound of a completely rebuilt engine seating the rings and breaking everything in?
 

DirtDonk

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Yes, and no. Can’t tell you what it was, or if it will come back or not, but it’s not normal for a brand new engine to knock loudly.
Something definitely wasn’t happy. But only the next few startups will find out if this happy time is permanent. Or not…

I’m hoping for permanent!
 
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skrit

skrit

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Yes, and no. Can’t tell you what it was, or if it will come back or not, but it’s not normal for a brand new engine to knock loudly.
Something definitely wasn’t happy. But only the next few startups will find out if this happy time is permanent. Or not…

I’m hoping for permanent!
Time will tell...

I was a fool when I was priming the oil pump the wrong direction a few weeks ago. I corrected that. I can't imagine that damaged anything. :unsure:

If it makes the sounds again, I'm dropping the oil pan for sure...tomorrow!
 
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