intermittent knocking sound at idle

[nitrofarm]

Whats the oil pressure at start up when cold and hot when it makes the noise?

[drddan]

Now replacing them.
1.) Can I just replace them with stock replacements?
Or
2.) Do I have to remove the crank and have it machined and matched to a new set of spec'd bearings?


And if by chance I have to machine the crank I should replace the mains as well just because.

You can use stock bearings, IF, the crank journals are still in good shape (which they should be on your engine)
Remove pan, remove bearing caps, and inspect the journals. If they are clean, and have no grooves in them, go with stock bearings.
You can "spin" the bearings in without removing the crank. Take off a couple caps and loosen the others, and you can install the upper and lower bearings with the crank in place. Then put the removed caps back on, leaving them loose, remove the other caps and do the same.

If your crank journals are grooved, then you need to have the crank ground and you will need new bearings to match the re-ground journals....or get another crank.

[rmoltis]

You can use stock bearings, IF, the crank journals are still in good shape (which they should be on your engine)
Remove pan, remove bearing caps, and inspect the journals. If they are clean, and have no grooves in them, go with stock bearings.
You can "spin" the bearings in without removing the crank. Take off a couple caps and loosen the others, and you can install the upper and lower bearings with the crank in place. Then put the removed caps back on, leaving them loose, remove the other caps and do the same.

If your crank journals are grooved, then you need to have the crank ground and you will need new bearings to match the re-ground journals....or get another crank.

Ok sounds good.
I'm gonna hope everything goes smooth.
It's too cold and snowy out now but when the weather warms up.
I'll be out there.

[rmoltis]

I took an 18" metal breaker bar and placed in against various engine components.
Then I would put my ear against it and use it as a stethoscope.

The sounds would transfer through it.
Once I got to the alternator I heard the noise quite clearly.
It sounded less like a knock through the "stethoscope"
And more of a rotating/off balance/bad bearing/drag creating sound.

I just yesterday bought a brand new alternator and replaced the old one.
Turned out the old one was a remanufactured unit.
It probably had shoddy workmanship and failed.

But I have a new unit installed now and the sounds all went away
And it should last for a considerable amount of time

[w4rkry]

Dont you love it when potentially terrible issues turn out to be simple fixes? Im glad you got it figured it out and didnt have to tear down your engine.