ok so the 305 with 305 ho heads that is in my car has roughly 1k miles..if that. It has roller rockers with a little over stock cam, nothing crazy. The rocker arms used to come loose on me about every 10 miles, i fixed that mess of a problem and it was fine for about 120 miles. now i have what appears to be a valve tap or rocker arm tap back...ok so they came loose again....no. they are still tight and exactly where i left them last time. the tap only happens when the car is warm, it does not do it when its cold and first start of the day.

I had already adjusted the valves with the engine hot and running so i know that is not the problem, so i think a lifter is shot. the tap is coming from cyl 5 exhaust.

here is a vid, its off my cell phone so the quality sucks but you can def hear the tap, its def in the valve train:

http://s47.photobucket.com/albums/f1...rovalvetap.flv

can anyone confirm its a lifter?

if it is then im leaving it alone till the car comes off the road in a month or so when im putting new cam, heads, and tpi.

thanks

 

Not that it matters that much, but until 1988, all f-body 305's got the same heads ('87 had center bolt valve covers and center two intake mount bolts at 72 degrees, but TPI and LG4 had the same heads that year as well).

Anyway, your recording has so much ringing to it I can't tell exactly what's what. How do you know it's cylinder #5? I'd check first for a header gasket leak. If it was a lifter, you should be able to quiet it with adjustment (although the engine will miss when the noise goes away if the lifter really is bad). If it is dirt in a lifter, a crankcase flush or a quart of ATF added to the engine oil may clear it out, unless the dirt is "hard" dirt, like sand.

 

i dont know why the vid is so useless quality wise...on my comp it sounds decent and you can figure it out...anyways i know its cyl number five because of the rod check, hold a wooden or screwdriver on the valve cover and you can hear a huge difference in noise from cyl 1 to cyl 5, even cyl 3 is quiet, now what gets me is you can hear the tapping more on the intake manifold than you can on the valve cover so that leads me to believe its lower than the rocker arms. if you listen to the fuel pump you can hear it really loud too..i dont know if that has anything to do with it.

as far as it being a head gasket, i really hope its not, but its no biggie if it is because im putting new heads on in a few months anyways.

oh and from what i understand from the guy i bought it from, its not a stock 305, he said it has some kind of 350 cam (that im iffy about..) and the heads are ported and polished...dont know if i really believe that, but the block is .030 over and it does have flat top pistons with valve reliefs. as far as fuel system, its a demon 625, no computer.

 

What I said was "header" gasket, not "head" gasket.

Anyway, if you can hear the difference with a wooden rod with the valve cover on, you should be able to hear it with the valve cover off. But, you said everything is tight. Not sure why you couldn't hear it with the valve covers off (or, did you not run it with the valve cover off?).

Did you adjust the lifters with the engine fully warmed up?

What roller rockers are you using?

 

sorry my mistake on the header gasket, on that side there are no leaks, the other side of the motor has always had one and i know what that sounds like, its not that.

I can hear the noise with or without the valve cover on. I meant was putting the wooden rod on the valve cover the noise is quieter than if you put the rod on the intake manifold. so if the noise was under the valve cover like a rocker arm you would hear it better or more with the rod on top of the valve cover instead of the bulk of the noise being on the intake manifold under the valve cover.

All the valves are tight, so are the set screws, i checked it the first time by feel with the motor hot but not running, because the last times they were so loose you could actually move the rocker arms as if they were not even tightened. They checked out this time, ok so i started it up making the noise isolated it to cyl 5 area tried to tighten them but it made the engine spit and sputter so i backed it off, all the time it was still making the noise. i did every valve on that side of the motor and they are tight.

I am using crane cams gold roller rockers 1.6, they were on my old 350 and were perfect, never made any noise. there were no signs of visible wear so i figured they were ok.