Milest

I started up my 72 L-48 today after about two weeks and I heard a tapping noise. I think one of my lifters is making noise. Quite distinct and does not sound like a exhaust leak. I would say it is #6 or #8 but I have not tried to isolate the area yet. I just started her up and let her run about a minute before shutting her down.

I'll have more time to check her out tomorrow I was just looking for comments on what to check and how to maybe resolve this issue.

I run Amsoil Z-Rod oil and valve train was always quiet until today.

Hmmmmmm....

Cool95vette

The first thing I would do is readjust the valves and see if it goes away.

diehrd

Check the heat riser on the pass side exhaust manifold.

Duane4238

If the engine is running smoothly and not missing at all, I'd let it run and warm up. My 72 did that on startup back in 1976 when I pulled it out of storage in the spring. I was sick when I heard it, but my landlord who had quite a car collection told me to let it warm up. He said one of the lifters probably bled down over the winter and just hadn't pumped back up. The noise went away after it warmed up, and I've never had it happen again. That was 40 years ago. Good luck.
Duane

doorgunner

I have never gotten the full "advertised mileage" from a synthetic oil....if the advertisement is for 15,000 miles between changes I usually change the oil and filter at 10-12,000 miles. Usually the oil pressure gauge shows a drop in pressure once the oil loses it's effectiveness.
You could also change only the oil filter...then add a quart of oil and see if the lifter quietens after running the engine at operating temperature for 10-15 minutes.......if it doesn't get quieter adjust the rocker arm nut slowly I/2 turn to see if the lifter gets quieter.

cv67

ck the heat riser and drive it for awhile should be fine

Rescue Rogers

Dont laugh, this works. Get a good length of small diameter hose and put one end in your ear. Dont let your significant other see or you wont live it down. Now use it as a stethoscope and place it in the noisy area and you should be able to isolate the problem. I found my vacuum leak this way. This is not a late April fool's joke. Seriously. Try it. Come on, you know you want to stick a hose in your ear and listen to your car

Could be a stuck valve, could be a low oil filled lifter, oil could be old and losing its ability to support the hydraulics. Weird but my old GTO did that when I was in the navy after a long deployment. It suddenly would run poor then die. After it cooled it started fine, but would slowly die when it got hot. Changed the oil and it never happened again. Go stick a hose in your ear and you'll figure it out.

Milest

I finally got a chance to check it again after a few days. There was still some lifter noise on startup, but not as loud and after about 2 minutes it was gone. I drove it for about 20 minutes and everything seems fine.

I really appreciate the comments and suggestions.

Cheers!

540 vette

If I leave my car without starting it for about 2 weeks or longer my lifters will tick until they fill up with oil. Never had a problem. They are edelbrock rollers.

Milest

Still chasing this ticking sounds after a cold start-up. I have been out of the country and getting my machine back in shape.

The ticking will go away after about 8 minutes of running. I put a piece of rubber hose after first starting her up when cold and when the ticking was obvious. The ticking is from the right bank, and I hear is clearly when I put the hose (home made stethoscope) on the #8 exhaust manifold where id bolts to the bead. No sound on the valve cover, or anywhere else on the valve cover. So now is it the exhaust manifold gasket or the #8 valve/ lifter? I'm trying to avoid pulling the intake and putting a new lifter on a existing camshaft and possibly wiping the lobe. I don't see any carbon around the exhaust manifold from above of below.

Once hot, it goes away.

Thanks guys

Rescue Rogers

You could have a lifter that isnt pumping up. Have you pulled the cover and checked the rocker arm clearance?

You could have a cracked spark plug that is shorting to the block and afer it gets hot the crack closes, you could also check and make sure the plug is tight and its not an exhaust leak out the plug as well

HeadsU.P.

For what its worth:

You can put an old lifter on a old lobe, same spot.
You can put a new lifter on a new lobe.
You can't put a old lifter on a new lobe.
You can put a new lifter on a old lobe.

If it were mine, I would want a visual on what's going on. You can do this by removing the valvecover and installing 8 rockerarm clips to contain the oil spray.
When you start it up, you should not only hear, but see something amiss.
On some engines, removing a valvecover is a 30 second job. On others, its a 15 min job, depending on how much stuff is in the way. But then you can grab some rockers, spin some pushrods. Get a feel for the valvetrain.

Milest

I found the problem. Exhaust manifold bolts on # 8 were loose. I was able to turn them by hand.
I tightened them up and checked all others (found one more loose on #1).

All quiet now when cold and after a 30 minute drive.

Thank you for all the suggestions.