Engine Noise?

[bigtee72]

Alright fellas. My '74 chevy full size has a 350 s/b. Hedmen Headers, Flowmaster exhaust (brand new). Edelbrock 600cfm carb. My question is: What is that awful tapping noise when it's running? Some say it's a valve tap, others say it could be a lifter sticking !?!? Any thoughts and somewhat inexpensive remedies would be most helpful. Thank you

[Prong]

It very well could be that the valves need adjustment. I'd spend the $15 for some gaskets and adjust them. Once that's done, you'll have a known baseline to work from.

[Captkaos]

How old is the motor?

[bigkountry]

Was it tapping before the new exhaust was put on?

I've had exhaust shops forget to fill in a seam and it sounds alot like a lifter tapping.

[bigtee72]

I'm not sure how old the engine is. I know for sure it isn't factory. It was tapping before the new exhaust was put on. I thought it was an exhaust leak, the old exhaust was awful. My old '79 used to tap, just not as loud. Exactly how hard is it to adjust valves(not tooo mechanically inclined). How much damage is it doing to the engine? I really don't beat it or anything this is my daily driver. Oil pressure gauge is reading fine as well.

[VileZambonie]

pinpoint it using a mechanics stethoscope.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_385487_385487?cm_ven=Aggregates&cm_cat=Google&cm_pla=Auto%20Repair%2C%20Automotive%20Diagnostics&cm_ite=160875&ci_src=14110944&ci_sku=160875

[78 Chevyrado]

It sounds like the valves.  However you said you have headers.  Headers don't muffle sound like the cast iron manifolds so there will be a pinging sound coming from them.  Buy a haynes manual, it's cheap and will have you on your way in no time.  TIP:  if you have to adjust your valves the valve covers must be removed.  To prevent oil spill (you need to adjust them with the engine running)  Buy a pair of used covers from the junk yard and cut the top off them, then it wll keep oil in the head and you can still get to the nuts for adjustment.  This comes to mind, and I've had my share....chevrolet: Can Hear Every Valve Rattle On Long Extended Trips...  

[SUX2BU99]

First thing I'd do is check the oil level. I know it sounds silly but I had a Daytona with a SOHC V6 that leaked some oil and I knew it was low when I would hear valvetrain noise. Granted, it would be all of the rockers making noise and not just one. Perhaps you had a rocker wiggle loose (which is what the valve adjustment is for) or a sticky lifter. I don't know if there is much you can do about that except to replace it.

[static22]

The valve cover trick works fairly well. You can also look to make sure the movement on the rocker arms all look uniform. If one is not maoving up and down like the rest. There is your problem. The cam or the lifter has gone away. Hopefully this isn't the case and you will just need to adjust the valve lash slightly. Check the simple stuff first such as an exhaust leak and possibly a plug wire arching.  Ive got a hydraulic roller cam that drove me crazy trying to get the "ticking" noise out but evetually found the link bars that keep the lifters from spinning were the guilty party and according to Comp Cams it was to be expected.  Good luck.