I just finished doing all the scheduled work on my 76 before I took her out for the first time. I replaced the oil pressure sensor, EGR vale gasket and put some new wheels and tires on her. I took her out for my first test drive and she purred like a cat! the secondaries on my Q-Jet even worked now and it had 40 percent more power. While on the test drive at kicked it a few times to see how it shifted and she performed great. Then as I was returning home all of  sudden  I heard the lifters tapping. I pulled over I didn't see anything wrong with the exception to some smoke off the manifold like oil was burning off. I checked the oil and it was full, the pressure gauge was reading 40 pounds with the engine running and temp gauge at 190 degrees. I and then drove it home slowly, hearing the tappets the whole time. When I got home I took off the rocker covers and inspected the lifters and valve springs but they looked fine. 

If you still have your valve covers off, set your engine to tdc 1 and push on the rocker arms to see if they are loose. turn the engine to the next position used, when adjusting valves in the two position settings, and test the rest of the rockers.

If everything looks fine and no loosness is found, put the engine on tdc #6 and check the exhaust valve rocker for loosness.

Simptoms that you describe are caused by contaminated oil &/or the camshaft is getting ready to self destruct. #6 is usually the first to go. We used to have problems like that all the time, but the oil companies added zinc to the oils and cam failures stopped. With the advent of overhead camshafts the manufacturers have requested that the oil companies remove the zinc from the oils to help them achieve less particulate emmissions.

I wish you well. autodoctors

I had that same problem, and thought it was the lifters (solid, on the LT-1), but it turned out to be an exhaust manifold leak. Especially prevalent with headers I'm told.

I had a lifter noise on the left side of the motor.  I poured in a can of "cure all" in a bottle...no change.  I finally discovered the left ERG valve that the manifold emissions tubes feed into was rotted thru on the bottom letting the lifter noise out.  Unable to find the EOM gold colored one I JB Welded it back together and it is still holding together 7 years later. johnu2007-06-07 06:41:34

[QUOTE=johnu]...I finally discovered the left ERG valve that the manifold emissions tubes feed into was rotted thru on the bottom letting the lifter noise out...
[/QUOTE]




You're gonna fit RIGHT in here, John!!!

Well, I adjusted the lifters and found them to be ok. It seems the actual problem turned out to be the combination of the crank and spun cap bearings.

Ouch!!!!

The ZZ4 ROX !

I love mine too..355hp added a hot cam and 1.6 rockers, ended up with 395hp..

Dang!! That blows...
Hang on to the original engine if ya can, for future caretakers...
ZZ4 seems to be a nice choice these days.