2001 volvo S60 2.4T thermostat
 

Has anyone used an aftermarket thermostat in the 01 2.4T? Its got that weird one with the pin on the top and I am pretty sure mine is original and shot and I cannot find just a replacement thermostat anywhere but I keep reading you can just replace it without changing the whole housing

I picked one up from my local parts store but its way different and will not work.

Which thermostat housing do you have? #15 is sold as a complete unit, #17 and #19 thermostat and gasket are not sold separately and have no part number listed. (by Volvo) #13 thermostat can be replaced by itself in that style housing, the gasket for it is a split oring #14 that fits on the edge of it. The earlier thermostat 271664 - fits all (most) of the 91-2001 aluminum block cars. (850,960,s70,s40,v70 etc)
The later style unfortunately is considerably more expensive -

https://cimg0.ibsrv.net/gimg/volvofo...a18cb5f66b.jpg
https://cimg1.ibsrv.net/gimg/volvofo...157dcfbc5c.jpg