In Reply to: Re: idle mixture trouble posted by JohnB on August 31, 2017 at 07:21:42:
Well you went to the right place for parts. On the exhaust manifold issue, it is common for these to get corroded out especially at the #4 port, nearest the downward exhaust port/pipe. That area gets the hottest and the mounting surface wears a channel that eventually will burn the gasket away and leak fumes. The manifold is suppose to use 7/16-20 BRASS Hex Nuts with steel lockwashers torqued at 27 ft/lbs. Some just use steel nuts and that makes removal difficult. To remove brass, get engine hot and let cool down a bit then try to loosen nuts normally. Use a good 6-point deep well socket to help avoid rounding off. If hard to budge, try spraying some PB BLASTER on them and let set for a bit. there are two paper gaskets with a new manifold, and some places use to sell the brass nuts with it as well. You do not need to apply any goop on the gaskets when installing. The reason for brass over steel is that the manifold constantly is getting hot and cooled down. With steel, the material becomes work-hardened and then removing from the studs becomes difficult. You might want to drain some coolant from the radiator first as a lot of times a stud or two come out and you'll get a coolant bath.