(2003 XJ8 - added by GGG)

Today, I replaced my thermostat. I have having a difficult time tighing the three brass screws. I'm unfamiliar with the threading but I cannot get all three screws to tighten at the same time are there any suggestions?

 

It would be a help if we knew what model and year car you are working on.

 

I'm currently working on my 2003 XJ8

 

The factory thermostat housing has brass inserts but the bolts/screws are steel.
The inserts can become loose in the housing and you probably need to replace the housing assy.

bob gauff

 

I swap the two hard to get at longer bolts on the back of the housing for two shorter bolts that hold the thermostat cover together.

 

I've added Model & Year details to your original post from your reply to RJ237.

You mention 3 screws so you presumably have a Supercharged X308 (XJR) and not the Normally Aspirated (XJ8) which has 4 screws securing the Thermostat Housing?

Graham