engine problem, please help

hi, my car has some problems and i was wondering if anyone knows what it is. its a 97 civic with d16y8. when i drive around when its warmed up, it makes clinking noises, kinda like the valves clapping or something. the idle is kinda rough, and it feels like it wants to die, but i raised the idle a little bit, to about 700-750, and idle is still kinda rough, but doesn't feel like it wants to die now. whenever i rev up rpms it fluctuates, down and then up about 200 rpm. so when i rev to 2500, and hold it, it goes down to about 2200-2300 and then goes back up. when it idles really low, and i floor it, theres clinking noises, the sound comes from the head, at first i thought it was just in need of a valve adjustment, but i dont know. anybody care to shed some light? has this happened to anybody before? thanks for your time.

have you tried the valve-adjustment? also check compression of the cylinders. did you do anything that might have hurt the car recently? when did it start, and what were you doing? answer that and we can see where to go.

recently i installed a turbo on my car, and then took it off, cuz it was leaking oil. while i was driving with the turbo on, it suddenly died, i started it back up and drove to my house, it ran really crappy, then i took the turbo kit off and sold it, and took my car to my friend's to fix it. he told me the timing was off 4 notches, he pulled off the head, and looked at the valves, said they were ok, got a new timing belt, and new distributor. ever since then, it started making that noise, at first i couldn't hear it over my exhaust leak, then i fixed the leak, and i started to notice the noise alot. when i let it idle, every 2 minutes or so, the idle drops from 700 to about 500 and feels like it wants to die, then the computer raises the idle back to 700, oh yeah, also, my thermostat has been broken for a long time, and because my water temp gauge was broken, i never knew about it, until i got another water temp gauge, it showed it was overheating and the fan wouldn't come on, so i changed the thermostat. the noise is noticeable when the engines warmed up, when it is cold, i can't hear it, not to say that its not there, i don't know. it sounds like something is loose, maybe like valves clapping.

so you were running a car that was overheating for a long time? if i were you i would take a look at making sure the head isnt warped. you may have even warped the block to some extent. that car has been through a lot, just take it in have it checked out.

the shop checked my block and head for warpage, hadn't warped much, so they put it back on.

what did they think was wrong with it?

i haven't taken it in to check out the noises yet. but everybody is telling me its the valves. i dunno whats wrong with the valves though.

could be the valve shaft is bent, so the valves arent sitting flush in the head. could be the head is warped just enough to cause the same thing.

you mean bent valves? but if i just rev it up, in neutral the noise is not there. only when i let it idle really low, and i give it alot of gas, it clinks 1-2 times. bent valves could have crappy idle right? whats valve shafts, is that valve stems? only when the engine is under load, it makes the noises. and the car feels like it has more low end than before, but the midrange, from about 3-7000, the rpms go up slow as hell, my rpms go up like the speedometer in my friends wrx.

i think your motor would have stopped working by now but have you checked your rod bearings:confused:

nah, i haven't checked bearings, i have never ripped into my engine before, have no experience so i am hesitant on doing it. however i have an 85 crx that i'm gonna rip into the carbed motor to rebuild it. i don't care about it much cuz i got it for 120 bucks, but i wanna do it for fun, no biggie, so thats why i'm not swapping in a zc or something.