Rough idle and knocking
 

Ok im trying to help my brother inlaw out with this issue but having no such luck. this is an 89 Fleetwood Brougham with the 5.0L. the problem is that the car has little power and sputters bad sometimes bucks and jerks when driving. And wont idle very well and die at times.

when warmed up it idles rough and at a low rpm say 500rpm or less it knocks (like when a car is dieseling) and sometimes dies afterwards but above 500rpms it seems fine but i can still hear the same knocking but a very quiet slight knock almost unnoticeable to the untrained ear. it also dies at stops or when put in gear.

i have sprayed carb cleaner in the carb to clean things up a bit to see if it helped. it seemed it helpd slightly but nothing major and the problem still persists.All while this is going on theres also smoke from it leaking oil near valve covers which im positive its leaking oil but in a small amount and it gets worse as rpms rise. I noticed that if i brought the rpms up and keep them there the smoke would thicken a bit and die down as the rpms droped. the cars not losing tons of oil but in a week or so i would say she would need 1/2 a quart. im not sure really what to do here or whhat the culprit may be. i was leaning to carb issues but i dont think its carb related ive seached on line and havent found anybody who had a straight forward answer to this issue. so im hoping some one here has had this issue. im mostly concerned with getting the car to idle smoot and go from there as far as the oil issue.

when the car is started for the first time of the day it runs great but still lacks power, then once it warms up this is when the problems with idle and sputtering and stalling (or plain just falls on its face) shows up. The knocking goes with the idle problems and disappears with higher rpms above 500. so i hope i painted a big enough picture to give anyone an idea of what is going on. the car only has 110k and ran like a top until after having the intake gaskets replaced. Then ran fine and later is when these problems showed up.