ok heres the low down.
1990 olds toronado vin c 3800. i bought from original owner who was to old to drive with 90k last season. its like a new car.

I have it up ta 110k now and I keep it tuned up and it wont let you go a day without missin an oil change.

here is the prob. once I get home from a drive on the freeway<truckin along> I stop while the car is still in drive and it idles down to around 625rpms it makes this dunk dunk dunk noise that can be heard well from inside the cabin but i was only able to hear it on the pass side while outside under the hood. I have replaced the crank pully and h20 pump so thats not an issue. from what the readout says the oil pressure is fine and the car can move out like a bat outta h*ll! but this noise bothers me.

maybe the oil pump? or worse like bearings or rods??
well for any advice.

is there a feeling that comes with it? like a jerk? is it always happen at low rpm? any sqeeking? does it speed up with rpm?

Its not the air conditioning compressor clutch kicking on and off is it. Justr watch it while its running. If you have the auto climate control on this clutch does this all the time. On and off. on and off. Its not a dunk? noise though just a clicking.

well i need a new condensor so its not the ac. and if you up the rpms it kinda goes away but kinda in part to more rpms = more engine noise.

that help?

Harmonic balancer ? Timing gear ? Power steering pump ? Alternater ? Water Pump ?Worse ?

One of the local shops had a thing on the counter that was like a poking fun comic strip about customers coming in and talking about noises and trying to mimmic the sound. Theres alot of stuff rotating in the engine compartment. Only someone right there could figure it out.

a) 625 is the normal idle, I kicked mine up to 700 toinprove the a/c when stopped.
b) given an odd engine noise a idle I generally pull the serpentine belt and let idle for not more than 30 sec just to see if the odd noise goes away. If it does one of the accessories is the culprit.

good call. I did that to figure out that my h20 pump bearing was makin noise when i got the caradn to figure out that my crank pully was clanging.. that ill try. if its not an accessory than what kinda stuffin the engine dunks? i do not beleive that my timing belt has been changed yet? when is that usually done? that and any other stuff that comes withh 100k miles?

d88

If it'* the harmonic balancer:

Turn the engine off and try pulling on the belts and see if you can get the pulleys to rotate back and forth at all.

nope.. its not the balencer.. listed twice thats its been replaced

does the oil pump make this noise if failing?

only happen in gear? in which gear? could you say anything more then dunk dunk dunk? like a DONG or a DING or somthing like that?