u/MembershipFair6190

So Ive been working on this 1994 Buick Lesabre- started it up one day and white smoke was billowing out of the hood, coming from around the exhaust manifolds while it idled rough- i replaced the upper intake plenum (as those are known for wearing out over time), and as that didn’t fix the issue, I replaced the head gasket, put it back together yesterday and started today, for it to be idling worse, and to have the same smoke come from around the exhaust. Any ideas on what it might be? I could have sworn it was gonna be the head gasket…