Shodori

Drove around for about 80 miles last night.

This morning started it up to back out and after about 20 seconds it started making this noise.

I had lifter issues a year ago and took it to a chevy dealer to get fixed but it wasn't this loud at all.

https://www.youtube.com/watch?v=ZgJSqbmaWN0

Thanks,

Dave Witman

May just be an exhaust leak.

calwldlife

calwldlife

not a lifter

check flex plate

Shodori

I looked up videos on Rod Knock i hope it isn't that

JoeMinnesota

I hate to say it, but I've had one motor in my past with a rod/spun bearing knock and it sounded pretty much the same.

I would start it and listen to the exhaust manifolds to eliminate exhaust leak, and listen from under the car and around bell housing, but if it's coming from deep within I would call spun bearing.

You could also pull the valve covers and do a quick check to make sure you don't have any studs that pulled partway out (lay a straightedge across the top) or find an obvious lifter or rocker arm issue.

jdmick

Does it get any quieter after it warms up? If it's an exhaust manifold leak they will sometimes quiet down as the gasket swells. Hopefully that's all it is.

If it doesn't change or gets louder as it warms up and as you rev it I would be more concerned about a rod.

terry82

I would get a long dowel rod or pool stick and place where you think the noise is coming from.then put the other end to your ear .the noise will get louder the closer you are the the problem.the one place you need to check is the fuel pump .they can sound just like that .

Jebbysan

I can never tell from those vids what the real issue is but I doubt it is a lifter.
Tighten all of your manifold bolts. If you find one loose, that may be it.....I had a 72' here a few years ago that a poor fella was tripping over....and it turned out one of his bolts fell right out......made a hell of a thwack when running......he was so ecstatic that he handed me $40 to stick a bolt in a tighten it.

Yes...as stated, the fuel pump can sound like that too.....the pump arm return spring peters out and combined with an old shaft......it can whack like mad.......my own 406 with a Holley pump made a tick and I traced it to that area....putting an ARP shaft in it fixed the tick.

And the flexplate can sound like that too as stated if a bolt fell out.....hell of a racket.

Also never rule out a spark plug wire arcing.......it can sound like a tick too.....

All good suggestions....good luck tracing it and let us know what you find.

Jebby

Indiancreek

I've seen converter bolts back out and sound similar to that.

Richard454

First thing I'd do- is pull the dipstick- take it into the sunlight and see if you notice any metal reflections. If you do- I'd drop the pan and investigate further.


I know videos are tough to diagnose- but it sounds a lot like a rod bearing... doesn't' sound like a tick....

Richard

CheezMoe

IDK sounds like something up top to me. I would start with the exhaust manifolds and donut gaskets. Is it louder on the pass side and have a heat riser on that side?

Dusky

That sounds like something hard hitting another hard surface every rev.
Doesn't sound like exhaust or lifters to me. Not fan either. Sounds like a bolt contacting the block/trans somwhere, or the feared rod knock.

LenWoodruff

Does the sounds change meaning faster ticks when it is revved up?

jeffwebley

I would be doubtful of a rod knock. Usually when a rod bearing gets clearance, you hear it when you rev the engine and let off the gas, it will make a noise as the engine decelerates. Quite distinct.
I would check exhaust manifold bolts and torque converter bolts ( if you have an automatic ).

The Money Pit

I had a Chevelle knock like that, and it turned out the starter Bendix was tapping the flex plate. Pull the inspection cover and look at the gears while the engine is running. You might see that starter gear popping around.

Sky65

Flywheel contact with lower shield can sound like that. Remove the shield and see if noise goes away.

Tom