Hey everyone, wasn't sure where to post this, as I'm not sure where the noise is coming from. I have a 1972 four door Chevelle, 350, 700r4 and 10 bolt w/ 3.73's. Had it up and running last year, and after I got on it a few times and heard a ticking noise at around 2,000rpm's. This noise happened whether in gear or park/neutral. Turned out to be a rod bearing. Pulled the motor, upgraded rod bearings and now I'm getting another ticking noise. Only this time it's intermittent, only under load (tried it in gear up in the air, couldn't replicate) If it does happen, it's around 3,000rpm's, doesn't matter what gear. Pulled the valve covers, everything checks out alright. Thought it might be the e-brake rattling against the exhaust, tore that out tonight and I'm still getting a noise.

I've searched the forums and I'm stumped. The rod bearing was kind of a double tap noise, where as this one seems like a single tap (if that makes sense). Also, I can't really get the noise to hold even if I stay at a certain rpm. So does anyone think this sounds dangerous, possibly blow my motor if I get on it at the track? Or just a harmless annoying noise I'll have to deal with? I'm fed up with this thing, about to throw it in the garage and buy a C5. Any help is greatly appreciated, thanks!

-Chris.

Hi.I dont know if this helps but one time I had a ticking noise that I couldnt figure out.. It turned out to be the header bolts. make sure the gaskets are flush also.. Just a thought.good luck.phil

Thanks for your input. Hrm, I never thought of that. I do have locking header bolts, perhaps it's the C-clips rattling around? I'll tape them all down and drive it tonight, keep you guys posted. If that doesn't work, I'll check the gaskets, they looked fine when I put them in recently.

This new engine only has about 800 miles now, and I haven't taken it past 4,000rpm's, if that helps. Transmission and rear end have about 2,000 miles, although it doesn't seem to be coming from there, but stranger things have happened.

Well, I put some heat wrap around the header bolt and retainers. Surprise surprise, it didn't make a difference.

Going to take it to my dad's work next week, throw it on the smog machine and put it under a load. Hopefully that will help diagnose it.

Do you have a rocker arm dancing around?A sticky lifter will increase your lash and clatter at that rpm.

Pulled the valve covers the other night with my brother. He knew what he was looking at more than I did. He said it was alright, guess I should get a second opinion. But nothing seemed loose, or am I thinking of something different?

Pull the plug wires off one at a time from the dist for that side of the motor.

If its an exhaust leak when the cyl thats leaking stops firing most if not all the ticking type noise will go away untill you re-attach the plug wire and it starts to fire again with ticking noise returning.

If you do this test and it doesnt seem to be an ex leak then try holding short piece of wood (1x3 or short broom handle) onto the valve cover on the side of the motor with the tick when its running.

The wood tranfers sound pretty good and you will be able to hear the ticking under the v/cover if its a loose rocker when you put your ear on the end of the wood with motor runnig. If you hear ticking readj the valves & check for bad cam by wathing rockers to see in one or 2 of same type(int or EX) are not moving tha same approx distance which woudl indicate a lobe wearing down.


I have used this wood trick may times over the yrs to find ticking rockers,bad mech fuel pumps,bad timing chains,bad water pumps,bad alt bearings,etc,it works for me.

Scott

I use a heater hose as a stethoscope, or would the wood be able to find something else?

Well just drove it today and pulled spark plug wires, one by one, and the noise was still there.