The intake manifold, head, and exhaust manifold must be removed to gain access to the gasket.
I just had the intake manifold gasket replaced on my 96 century yesterday and my bill was $450 but my gasket was only leaking out. If its leaking into your oil it may be more.
Plan on at least 6 hrs.
The head has to be removed on the 1993 Roadmaster to get to the gasket. You will need to remove the intake, exhaust manifold, and valve cover then unbolt the head to remove it. Check the head for warpage while it is removed.
What's wrong with it?
The 1997 Buick LeSabre intake manifold bolt torque specifications is 45 pounds per square inch. The manifold bolts should be torqued in 15 pound intervals.
Never have seen a blown head gasket on one. You most likely need an upper intake manifold. This is a common problem the new replacments are made better and will last longer. Buick parts person for over 20 years.
replace the water heater inlet pipe on the intake manifold on a 3800
you will have to unbolt the exhaust pipe from the manifold pipe and then you unbolt the manifold pipe from the engine, remove old gasket and make sure both sides are clean of the old gasket and then install new gasket and bolt manifold back onto engine.
The 3.1/3.4/3.5 are known to have lowe intake manifold gasket issues. If this gasket goes, water from the cooling system goes right into the oil, mixes, and turns the oil into a chocolate milk looking fluid.
Exhaust manifold gasket leaking
Head gaskets do not go bad on these. You need to replace the plastic upper intake manifold as it is leaking coolant into the combustion chamber. Common problem for this engine.