Hi all, changing the thermostat on a series 1 XJ6. I've included a picture of the new thermostat in situ but confused about the rubber washer that came with the part. Is it necessary; where does it go?


The old one doesn't have the washer, just the gasket.


At this stage my plan is to skip the washer and put sealant on the gasket and seal her up again, with anti-seize on the bolts. Car hasn't been leaking and the thermo was working until this week, so I'm not sure what the rubber washer would be doing. I'll wait till I hear from some of you with experience before finishing the job, however.


Massive thanks to some earlier entries on here -- especially things Grant and Jose have said in earlier posts about that long third bolt holding the housing: what a bear to get at.


Thanks for any thoughts.


Graham

 

My generic view is that it is an internal seal. To keep coolant from bypassing the t'stat.


I would install it and the external paper or chemical gasket. .


Carl

 

That is a multi purpose thermostat. There are some housings that have a big groove in them. On those you'll have to put the gasket on the thermostat(can you see the groove in the gasket?) and then install the whole thing at once. The half that you show in the picture does not look like you need it. I've only seen them used on after market housings on Chevy. Looks like if you try to put it on then you'll end up not getting a seal. Just be sure to use some type of form a gasket.

 

The Jaguar XK engine only ever used a gasket on the thermostat. The rubber ring you have is for an alternative fitment for that thermostat; for a more modern engine, basically. The thermostat makers have been kind to you in providing alternative seals. It saves you getting stuck with the thermostat housing dismantled !