Bought the car a few weeks ago, (98 Camaro 3800 series 2) with bad head gasket. The motor made no mechanical noises at that time. I replaced the head gasket... overheat problem fixed, but a tapping noise appeared a day later. I figured a valve lifter was the problem so I changed all lifters and pushrods...no fix. I thought maybe the radiator fluid damaged a bearing so I replaced all connecting rod bearings and checked wrist pins on each piston, no play in them...no fix. The tapping still sounds like a valve lifter. I would of staked my reputation on it. Put a machanical oil guage on the car and the pressure is running at 60psi...normal. I rule out low engine oil flow. This noise seems to be at the front center of the engine. This tapping sounds exactly like a lifter !!! What puzzles me most is that sometimes the noise will disappear for a bit and then come back running 5w 30 weight oil currently. I tried a heavier weight oil...no fix. I am beside myself here...someone HELP PLEASE. Thx John

 

Damaged rocker arm? Did you check the lift of the cam lob. Sounds like you have the motor all apart was there any play in the timing chain? Any play between the Cam Gear and the balancer gear? Did you check the timing chain damper? Did you pull apart the pump assembly?

 

I've heard of timing chains getting so much play that they hit the timing cover. might be something to look into.

 

These motor have a chain Damper, almost like a belt tensioner.

He needs to get the valve cover off and run the motor and see it the noise is valve train or not. It could have a pluged oil passage that is feeding a lifter.

 

Didnt know that. How do you check wrist pins without removing the pistons?

 

Thanks for the replies. As I said in my opening statement the car had no mechanical noises to start with. It had to be induced by me. The noise is with the piston speed. A timing chain or dampner would be erratic with no consistant beat. I believe I have an oiling problem since the noise will diminish at times. I tend to think as GORN does. I think it may have an oil restriction but I have had the valve covers off looking for this and am unable to see anything that hints at it (low flow from rocker).

 

An exhaust leak can sound very much like a noisy lifter, enough to sometimes even fool a trained ear. Since you removed the exhaust manifolds from the heads, I would check there first. Did you put on new exhaust man. gaskets, or reuse (bad idea) the old ones? And did you re-torque the exhaust manifold bolts back down after the first heat & cool down cycle?

 

Short of putting two thick a headgasket to not tighening rocker I have no clue what you could have done to cause this. I would not look for flow as much as I would find the noise first. With oil clips inplace you can let the motor run. You should be able to feel the rocker making noise.

I had a customer come in one time. He had just installed a new cap/wires/plugs when he was done the car would not start. He road in with the car. He convinced me it was something he did. I had the distributer all the way out. After about an hour of this I put everthing back together and started like it was a new no start. His fuel pump had failed. Sometimes crap happens at a bad time.

 

ok...I pulled the timing chain cover to remove any doubt there. As expected the timing chain and dampner are in good shape. The balance shaft has a small amout of play in the gear lash. Book says 2-5 thousanths is normal. Anyone ever hear of the balance shaft making a tapping noise???

 

any sign of heat or excessive wear on the lifters that u took out.