In early 1996 Ford started using a plastic intake manifold on the 4.9 engines for the Crown Vic, Grand Marquis and the Lincoln Town Car. These manifolds have had a problem with cracking around the area where the alternator bolts to the manifold. In late 2000 they started putting a stronger partially metalic manifold on that engine. Ford does not cover this problem on their warranty unless it is a police car or commercial use vehicle. Private vehicles are not covered. I have a 97 Town Car that has that plastic composite manifold and am wondering if anyone out there knows where I can get the improved manifold from without going to the dealer and paying an arm and a leg? I was told the older 4.9 metal manifolds will not work because of the re-design for the newer type EGR valve that is used. I am not sure if the F-series truck 4.9 has a plastic manifold or not. Any help will be appreciated.

 

Try doing a search for "cracked intake" at http://www.crownvic.net/ubbthreads/index.php .
It seems to be a pretty popular topic there.

 

That would be a 4.6 not 4.9. This may be an inprovement made in 99 with the PI heads. They have a totally different intake port and a 99-up intake can not be used on 98-back heads unless you can come up with adapter plates and then you have to watch hood clearance problems.