Car sat and now it clanks

[xrunner123]

Car sat for a few months as I was doing some exhaust work and I replaced the turbo. I started it up today but as soon as it started there was a loud banging/clanking noise at idle at the top of the motor- I turned it off after 30 seconds. Car ran fine before it sat.
I pulled the plugs for inspection and the valve covers. I am no expert but I do not see anything bad.
What could cause this and how to diagnose it? Can I run the car without the valve covers to see if they are running properly? I don't want to make it worse.
Thanks in advance.

 

[Rahob]

I probably can't help you, I'm still very new figuring out all the different bad clanks, but maybe I can help someone else help you. If you're willing to run it again for a brief time and upload a video of it to YouTube, maybe someone could recognize the sound and guide you.

I had a bad water pump making a clanking sound that sounded like it was coming from the top front of the engine.. if that helps.

Good luck.

 

[hensleyt]

This happened to a 454 I borrowed to pull my Big ass boat. It ran perfectly the 600 mile trip. I change its oil and retired it to his happy owner, it sat about 3 or 4 weeks, and when he went to hook it to his travail trailer the thing sounded like a rod was out.
I pulled the engine that night turned it upside down pulled the pan and it was beautiful inside. Called a old mechanic friend told him about the noise and he laughed. Told me to reinstall start it . And low RPM (1500 if I remember right )pore ATF down the carb, said it was carbon that came loose from the head after setting and couldn’t get out the exhaust valve. He said add slowly tell the noise went away. Worked like a camp.
I’ve heard people use a spray bottle of water and misting the intake, same result.
A little scary to do to our pride and joy.

 

[Chuck Leeper]

Lifter bleed down??
Oil psi ok?

 

[hensleyt]

That’s a good thought
I had a lifter feel but while driving

 

[earlbrown]

I vote lifter. And for some reason when they go down on these engines they flat out don't want to pump back up unless you kick the crap out of it.

 

[hensleyt]

I retract my carbon post and second lifter

 

[xrunner123]

Oil psi was good at start.
So of it is a stuck lifter how do I unstick it? Is this an easy fix?

Can I idle to further diagnose it or can it cause some damage?
Thanks

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[xrunner123]

I vote lifter. And for some reason when they go down on these engines they flat out don't want to pump back up unless you kick the crap out of it.

Hi. Can you explain more on what you mean by this?
Thanks

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[earlbrown]

Lifters make noise, then they shut up when you fill 'em with oil.

Or you broke a rocker shaft and they won't shut up until you replace the shaft.

 

[xrunner123]

Here is a video.
Thoughts? Thanks

 

[Chuck Leeper]

At startup, it sounds like a loose brg.
A serious knock as the starter is engaged.
I had the same problem. It was #6 rod brg going south.
Time for an inspection of the lower end.
As a preliminary, I'd check to see if the converter is loose, or the flex plate is cracked.
Unhook the converter, and push it back, restart.
Also, take the belt off.

 

[xrunner123]

Ugh. Wtf. Car ran fine before I started working on it.

Can this be something stupid I did or does it sound so bad something is broken big time internally.

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[Chuck Leeper]

The way it's sounding, now, keep running it, and the issue will make itself well known...AKA, a rod thru the block.
It makes no difference if it was you, or it was time for a problem to be showing itself.
Cut the oil filter open, see what's there.
Oh, and read post #12, and followup w/ results.

 

[Bullnerd]

Old timer once told me,

If you rev a little and let off and hear a knock, its a rod.

If you put it in gear and load the engine against the trans and hear a knock its a main.

Did the engine shake a lot when you started it?

Does it knock that loud on start every time?

If the engine is shaking a lot, it sounds like your exhaust is hitting something to me, but hard to tell without being there.

The other just sounds like valve train clatter. I had a ford that did that when you went around an off ramp! lol!

 

[xrunner123]

I cut open the filter and it's clean. Thing is though I changed the oil and filter before I started it and had this issue so it only ran for a few minutes.
I looked and the flex plate and the converter is not loose and restarted without the belt. Same sound. It is coming from inside the motor.
What to do next? Drop the oil pan and inspect?- This part is new to me.
thanks

 

[KC87]

I cut open the filter and it's clean. Thing is though I changed the oil and filter before I started it and had this issue so it only ran for a few minutes.
I looked and the flex plate and the converter is not loose and restarted without the belt. Same sound. It is coming from inside the motor.
What to do next? Drop the oil pan and inspect?- This part is new to me.
thanks

Did you actually torque the bolts down? Had this happen years ago after slightly over revving and the knock was intermittent but sounded like nails across a blackboard. Don't know what made me think to check the bolts but they needed tightening and that cured it. The sound seemed to echo all over the place. The bolts weren't physically loose to the touch but was surprised how much they turned to achieve the proper torque.

 

[Bullnerd]

"doing some exhaust work"

Im guessing this is part of the problem, the loud one at startup. Lay under/beside the car while someone starts it and listen.

The other is lifter noise like was already mentioned. Do you know how to prime the engine with a drill?

Did the engine run normal before the mods?

 

[xrunner123]

"doing some exhaust work"

Im guessing this is part of the problem, the loud one at startup. Lay under/beside the car while someone starts it and listen.

The other is lifter noise like was already mentioned. Do you know how to prime the engine with a drill?

Did the engine run normal before the mods?

Thanks. I know I mentioned I did exhaust work but now thinking back after I installed the new mufflers I took it for a ride and motor sounded fine.

 

[Chuck Leeper]

What to do next? Drop the oil pan and inspect?

^^^ This.