2001 Ranger 4.0Liter
This is kind of weird after all these years, but the housing is leaking out of its lowermost seam. The housing does not appear to be cracked. Mounting bolts are torqued tight as can be. I see no evidence of a gasket.
Is there an 0-ring within?
Is it possible to get into the housing without removing all the stuff above it?
If possible, what sort of seal is within that seam?













i

 

It takes an o-ring; there is no paper gasket. I'd just take it apart, make sure there are no cracks in the housing or the lower intake, install a new thermostat and o-ring and be done with it. Avoid the cheapie thermostats that some places, especially online places, have on sale for a little over a buck.
And as you have probably already surmised, this is not the easiest thermostat/o-ring in the world to replace.