My 1980 corvette started idling funny , it will idle smooth for a while than sometimes it will idle smooth than all sudden drop 100 rpm than go back up 100 rpm back and forth and also the oil pressure is fine at start up and when the motor is cool than after it is drove for a few miles and the motor temp gets up around 190 the oil pressure drops and bounces around 20 some to 30 instead where it use to around 40 steady .. when i step on it it still has pressure and it will go to 40 but at idle and normal driving it is low it also when the motor temp gets up around 190 and my oil pressure gets low makes a chattering sound that i thought was my lifters at first maybe sticking but it couldnt be because when it is in park it doesnt do it it only does it when your in drive and going up like a hill or when you are on the gas.A guy that looked at it said my carb needed to be rebuilt or a new one and that my intake was leaking and that gas was getting into my oil and that was why it was making the chattering sound and thats why my oil pressure was low and said i needed new intake gaskets ... could this be it ??? have any of you had this problem .. my car has only 57,000 miles on it i only drive it once in a while coiuld it sitting a lot have caused this ? any help would be appreciated .. thanks

 

sounds like two different problems or, what ever is cuasing the oil problem is pulling the engine down 100 rpm's.

I would check your oil system first. Drain the oil and replace fileter. Open up the old fileter and look at the media for anything odd, also look at the old oil for anything wrong. Make sure you use the right viscosity oil.