Hydraulic Lifters

Yes, the lifters should have been changed when you changed the heads. If you had solid lifters it would have been ok to reuse them, but not hydraulic. As to how they work, this is something that can be googled easily, popular hot rodding has a good article in their archives about hydraulic and solid lifter comparrisons. If you followed all the installation instructions properly and pre-load was set correctly, maybe you did not have the right lifters.

"maybe you did not have the right lifters" I used the old lifters, so they can't be the wrong ones. Another strange occurrence, is, after setting them up, starting the engine and getting all that chatter, then removing the covers again, some of the rocker arms are just flapping in the breeze, so to speak. I mean, it seems that the nuts are loosening up when the engine runs...got me baffled, since I checked each lifter, before re-installing the intake manifold. I am thinking that I do have a problem with the lifters...which brings me to another topic...some are saying, install new lifters...install a new cam as well, while others are saying it is ok to use old cam, because of the forgiving nature of hydraulics lifters. Damn, I wish I knew for sure, replacing the cam means the engine has to come out of the car, YES? Can't see any other way with a transverse mounted engine...should have just bought a new engine, stioll might, know anyone who wants to buy two new heads for a 3.1 V6...lol Thanks also for the previous response. Cheers

If you put in new lifters you should also replace the cam since the cam will have wear from the old set. If you placed the old lifters in their original position and also placed the rockers in their original position you should be able to get away without replacing the cam or the lifters. I replaced the rockers in the engines that I worked on thus I changed the lifters as well. Your problem with the rockers coming loose may not be from the lifters but from the rocker nut. While they are reusable, some vehicles use a pinch nut. Every time it is removed it does not grip as well as before. A new set of rocker nuts may fix the issue.

Well now, it has come to my attention that 3.1 V6's from 1989 & newer, DO NOT REQUIRE ADJUSTMENT, the rocker arm nuts are torqued to 20lbs. and voila you are there. I would have thought that all you car gurus here would have known that. albeit, that I had to re-read the Haynes manual to discover it myself, my bad, gotta slow down and read between the lines, or, as in this case read all the lines. Thanks for trying to help. Regards