The heat riser in my manifold is rusted in place. I don't know if it is open or closed. My question is, how critical is it that this be freed up? What are the consequences of being stuck open or closed? Thanks, JW
Open will overheat your intake, often causing vapor lock. Closed will make it warm up the incoming much slower.....no problem if you live down south.
My experience servicing these when they were nearly new says many were in need of freeing up. The cure then was taking a SMALL hammer and alternately tap both sides of the flat side till they freed up. I can't recall it ever not working...
What HE Said ! Of course , before you touch it you'll want to soak it with Chrysler's Heat Risor Solvent , this is *THE* stuff to use as it's a penetrant with graphite so after you get it loosened up, the graphite remains to lube it.... BE GENTLE ! the shaft is *very* easy to break , no new parts for this .