engine knock

[myaddress2020]

hi all
i wonder if anyone can give me some insight into a peculiar knock that started on yesterdays run. while i was going along a steady knocking started. engine acted normal. when i stopped the knock remained but it was not a steady one. when it is at idle it is an unsteady knock. when throtle is pressed it is a constant banging. it seems loudest on the passenger side. i thought a valve spring but the engine would run bad if it were that.
any suggestions of where to look or try would be appreciated.

[Wm J.]

Sounds like the timing gear nut came loose. Take off the side inspection cover and check for movement of the gear on the cam.

[myaddress2020]

ok so i put the timing pin in while it was running and it wasnt the gear slapping back and forth.
there is no in and out movement on the water pump shaft and i touched the distributor shaft and it went up and down only slightly.
still not sure...

[modelAtony]

Originally Posted by myaddress2020

hi all
i wonder if anyone can give me some insight into a peculiar knock that started on yesterdays run. while i was going along a steady knocking started. engine acted normal. when i stopped the knock remained but it was not a steady one. when it is at idle it is an unsteady knock. when throtle is pressed it is a constant banging. it seems loudest on the passenger side. i thought a valve spring but the engine would run bad if it were that.
any suggestions of where to look or try would be appreciated.

Sounds like you have a main bearing knock, this normally is heard at powering up .

[myaddress2020]

i hope your wrong, this a brand new rebuilt engine from schwams in PA

[H. L. Chauvin]

Sponsored Links (Register now to hide all advertisements)

Hi 2020,

Try getting any kind of a wood stick, dowel, broom handle, 2x4, 2x2, & place one end on several items & the other end on your ear.

Maybe test the distributor, valve cover, side timing cover, water pump, generator, engine head, oil pan, & anywhere you can imagine to try to hear where the knock is originating.

Be most careful to stay clear of the fan.

Report back what you heard -- it may lead to something more definite.

[V4F]

my first thought was center main . maybe a valve is tight . compression test may help . good luck ........ steve

[billwill]

Short the plugs one by onelisten for noise

[Tom Wesenberg]

Is it a loud metallic knock, or a deep thud, or a lighter ticking noise? Or is it engine ping, kind of like popcorn.

[myaddress2020]

i took it to a friend today who has a sthesiscope and he thinks its a broken piston pin in the 4th cilinder. we looked in the trans inpec plate and he didnt think it was wobling so he thinks the rear main isnt it. it doesnt make noise in retard only in advance.

[Will N]

This is the friend who looked at it. As 2020 said, the rap goes away when the spark is fully retarded, and comes back when you advance it. We shorted out the plugs while running at idle with the spark advanced, and the rap stopped when #4 was shorted out. We put the stethoscope against different areas on the #4 cylinder, and the rap was clearest when it was placed against the cylinder wall, below the water jacket. I'm inclined to think that it might be a bad piston pin, or maybe the rod bearing.

[James Rogers]

Better call Schwalms and get his advice if the warranty is still in place. If you are out of your warranty period you will need to start taking it apart till you find the problem. Mind you most warranty periods are from acceptance of motor till specific period in or out of the car.

[1931 flamingo]

I think I would contact builder BEFORE I dis-assembled anything. JMO
Paul in CT

[Mitch//pa]

Let us know how you make out with the builder and warranty work

[afuncar]

It may be piston slap?contact builder. Many times if piston slap it will stop when engine is hot.