Valve Sticking

Just recently had a 97 Lumina 3.1 dropped into a 95 Monte Carlo. The motor had been sitting for a while. After the motor was put in, it began making a loud knocking noise, with a softer tapping noise in the background. The louder knock isn't consistent, but the tapping is. These noises began with the first firing of the motor. The mechanic believes it is sticking valves. We added a bottle of Rislone to the oil, and the sounds improved, but didn't stop completely. Around 1500 RPM's there isn't much noise, but still noticible. The car lacks power and backfires through the exhaust when reved high enough. Any suggestions, or possible diagnosis?
Thanks

Just recently had a 97 Lumina 3.1 dropped into a 95 Monte Carlo. The motor had been sitting for a while. After the motor was put in, it began making a loud knocking noise, with a softer tapping noise in the background. The louder knock isn't consistent, but the tapping is. These noises began with the first firing of the motor. The mechanic believes it is sticking valves. We added a bottle of Rislone to the oil, and the sounds improved, but didn't stop completely. Around 1500 RPM's there isn't much noise, but still noticible. The car lacks power and backfires through the exhaust when reved high enough. Any suggestions, or possible diagnosis?
Thanks
Just put a 1.9 in a escort for son, been sitting awhile too. Had collasped lifters. I ran it with new 5w30 oil at about 1500 rpm for about 15 minutes, that cured most the tapping but not all. I pulled the valve pan and using a rubber mallet with engine OFF.i lightly pounded on the lifter end of each rocker arm about 20 times on each. Put pan on and no noise whatsoever now, Will it work for you? could, maybe not, who knows, try it. Also if its a engine that doesnt spray oil every place with valve pan off, you can tap on them with engine at idle too.
Could aslo try a quart of dexron tranny fluid in it and let it run awahile and then change oil, some swear that will work, i never tried it.

Just put a 1.9 in a escort for son, been sitting awhile too. Had collasped lifters. I ran it with new 5w30 oil at about 1500 rpm for about 15 minutes, that cured most the tapping but not all. I pulled the valve pan and using a rubber mallet with engine OFF.i lightly pounded on the lifter end of each rocker arm about 20 times on each. Put pan on and no noise whatsoever now, Will it work for you? could, maybe not, who knows, try it. Also if its a engine that doesnt spray oil every place with valve pan off, you can tap on them with engine at idle too.
Could aslo try a quart of dexron tranny fluid in it and let it run awahile and then change oil, some swear that will work, i never tried it.

The tanny fluid trick may help, there is a product called Marvel Mystery Oil that works wonders with lifter problems. It has a lot of the same detergents that Trans fluid does, but with extra solvents. I'd try running some of that through it.

Interesting what you said about tapping on the rockers. I've sometimes had to compress the lifters to force crud outta the passages and get them to fill with oil, I guess that is in effect what you did.

The tanny fluid trick may help, there is a product called Marvel Mystery Oil that works wonders with lifter problems. It has a lot of the same detergents that Trans fluid does, but with extra solvents. I'd try running some of that through it.

Interesting what you said about tapping on the rockers. I've sometimes had to compress the lifters to force crud outta the passages and get them to fill with oil, I guess that is in effect what you did.

Yeah, but too, i have done this over the years on a lot of old engines and ratio that it works to doesnt work is about 50 to 1. LOL just got lucky this time i guess, but since it isnt a hard thing to do, i figured id throw it in, ya never know with engines.
Yep, the ole Marvel Mystery Oil, remember seeing my uncle use that 40 years ago.
Did ya ever see anyone warm up a engine, hold throttle about half way open and pour slowly about a quart of water down its throat? he used to do that too, says it cleaned (steamed) clean the valves and such.

Thanks for the input folks. I did manage to find out that the lesser of the 2 noises was #4 and #6 plug wires were reversed somehow. That fixed the backfiring threw the exhaust issue and the loss of power. Still have the possible valve train noise or perhaps piston slap noise. From what I read threw the forms though if it were piston slap the noise would not be constant. Would that be correct? Valve train on the other hand would be a constant noise. Since I lost the lesser of the noises the other louder noise is a constant thing and appears to have a slight harder rap to it at both idle and on rev but the hard rap isn't constant. It's mixed in with the tapping noise.

My '97 has always had a lot of top end clatter, especially in the morning. My usual routine is to start it, let it idle for 2-3 minutes, then I slowly bring it up to 2500 RPM then bring it back down gently to idle. At that point most of the noise is gone. After complete warm-up, the motor is quiet, you have to open the hood to hear the faint valvetrain noises. All these that I've dealt with are noisy. Some more than others, but they all sound like a can fulla rocks rolling down a hill in the morning.

Sometimes if it's real cold out, I can hear the piston slap as I bring it off idle for the first time, but it goes away fast and I never hear it in the warmer seasons.

These 3.1 engines use a "zero lash" rocker assembly. Because of the design of the intake manifold, it is impoossible to access the rocker arm nuts after the engine is assembled, so the rocker arm nuts are torqued to a value instead of being lashed. As these engines get older, clearances increase and the lifters lose some of their spring tension causing the "normal" lifter tick associated with these engines. Since the motor sat for a while before you installed it, there is a good chance that you have sludge in the lifters increasing the likelihood of a tick. My suggestion would be to continue to try extra oil detergent additives for a while to see if the noise goes away on it's own. If it doesn't, I suggest taking the valve covers back off and manually working the pushrods in and out of the lifters to force the hydraulic portion of the lifter up and down in the bore. This may free any that are sticking and eliminate your tick. Also, 95 was the last year for a flat tappet cam, all 96-up had roller lifters. I believe the torque spec is different betweent the two, as is the intake gasket. IF you had the intake off the replacement engine, make sure you used the proper gasket for the year of the engine. Some 95's had the roller lifters also, so it's possible both motors are virtually identical, but there is a chance that you put a roller motor where a flat tappet used to be, so be aware of these differences when replacement parts are needed later on.