What happens if you put the thermostat in backwards? 1998 XK8

 

If it fails to open the bypass won't open. This could cause problems during warm up as NO fluid is flowing to engine.
With a thermostat failure the by pass won't open because flow is holding it closed and you can overheat.
It needs to be in correctly and with the by pass in the proper orientation.

 

Do you know of an illustration showing the proper orientation for the thermostat?

 

Hi.
Here you go.

 

Not necessary, the spring side goes into the housing with the bleeder at the top.

 

you beat me to it, I was going to post the same image.

 

Well, I have it installed correctly. I guess that's not my problem. Ratz!
Thanks for the help.

 

So what exactly are you having a problem with, maybe we can help?