Need Help, knocking-pinging

[mhoflin]

Hey all,
I need some help on my 81 Chevy C10. It started knocking - pinging on the way home the other day. It just started out of nowhere. I have changed to 91 octane fuel, changed plugs and checked timing. All are good but I still can't get rid of the "Tick - Tick - Tick" only under load or if I rev up the engine. I am at a loss, if anyone has any ideas or has had the same issue, please let me know.

Thanks for all your help!

[Killer Bee]

can you take a video [for audio purposes], upload to youtube, and post here?

[Dead Parrot]

A small exhaust leak can sound a lot like a 'tick' and often reacts like your noise is.

[mhoflin]

Thanks everybody for replying! Any and all help is greatly appreciated.

Sorry, I don't have the ability to take a video. No video camera or smart phone, I don't like smart phones.

Exhaust leak is not it, the noise can be heard through secondary carb barrels when revving up. It is only present when rapidly increasing RPMs and while under load.

[abig84]

I always thought it was from having a lean condition? My obs with a tbi 305 used to do the same thing and the exhaust always smelled lean and so did the plugs but ran great so I never wanted to mess with it. Premium fuel did fix my issue but got expensive so I did it every other full up.

Unfortunately I don't know a fix as it magically fixed itself after like 4 years of doing it you can google premature detention and read up on some articles

[Dead Parrot]

If the intake is OEM or similar, a bad intake gasket can cause an exhaust leak from the crossover passage. I was chasing a vacuum leak and when I replaced the intake gasket, a pesky exhaust tick went away as well.

[mhoflin]

Well guys & Gals,
So far I have changed the Intake Manifold Gasket, Dist. Cap & Rotor, Rebuilt carb, Changed plugs, Tightened Exhaust manifolds and I still get that stupid "Knocking/tapping" and I checked all rockers and they are good.

I am at a loss. It started out of the blue coming home from running errands and I can't get it to stop. A shop I take it too for the real big stuff, because of my disabilities, retarded the timing way back and it seemed to work, but the truck runs like crud!

I could really use a miracle here. Any takers?

[68longhorn]

I have a feeling your cam and lifters are starting to fail

[Getter-Done]

Is the mechanical advance working?
A way to check is to take the distributor cap off.
Then turn the rotor button with you hand it should move about a 1/4 inch or so. If it does not move at all the shaft is seized up.
While you got the cap off check the springs on the flyweights under the rotor button.

[farmall]

Flexplate?

[mhoflin]

Well, I am starting to get the feeling it may either be cam & lifters or maybe rod bearings. I really hope not, being disabled limits finances greatly. But I do know it is not a flex plate as I had all the seals in tranny replaced and the flex plate was fine. In any case, I think it is not going to be something small or easy to fix. I am still hoping for a miracle revelation to be the answer but not getting my hopes up.

[Dead Parrot]

Take all the belts off and see if the noise is from one of the accessories. Plus the lack of fan noise might make it easier to find the noise. Just don't run it very long at any one time.

Is the noise there when the truck isn't moving? A brake pad wear feeler can sound like a tick when the vehicle is moving.

[mhoflin]

It makes the noise when in gear and I bring up the RPMs, powerbraking. I have no clue but I will try taking the belts off to see if I can narrow the location down. Other than that I will have to wait and see.

[mMad Dawg]

I know this is an old thread but have you checked to soo if your torque converter bolts have loosened up. I ran across this before. If they are loose put smome thread locker on them when you tighten them up. Good luck hope this helps. Gord

[Getter-Done]

Originally Posted by mMad Dawg

I know this is an old thread but have you checked to soo if your torque converter bolts have loosened up. I ran across this before. If they are loose put smome thread locker on them when you tighten them up. Good luck hope this helps. Gord

Good Idea for things too check.

[cadillac_al]

Originally Posted by mhoflin

It makes the noise when in gear and I bring up the RPMs, powerbraking.

That kinda sounds like an exhaust leak to me. If you want to rule out actual detonation you could try a tank of premium fuel to see if it goes away.

[farmall]

"All are good but I still can't get rid of the "Tick - Tick - Tick" only under load or if I rev up the engine." "I had all the seals in tranny replaced" "It makes the noise when in gear and I bring up the RPMs, powerbraking"

"torque converter bolts", Flexplate.