Went to replace thermostat today....got one from advance but it looks way smaller and lighter so I put the old one back in but now idle jumps up n down and I tried bleeding at screw at thermostat and I'm not getting any fluid at screw .. ..any idea wat issue could b

 

are you getting anything from the screw?

 

No just air

 

keep bleeding it then haha
you have radiator topped up and giving the car enough time to warm up?

 

Yes its at normal temperature thas when erratic idle begins