Thermostat Types and Availability

[rgorke]

Before I start this, the entire cooling system has been replaced less then 25k miles ago. I even put a larger radiator in and a water pump with the metal impellor. The system had run perfectly during the summer with 120degree weather sitting in LA traffic.

This morning while taking my spawn to school, I heard my fan go into overdrive and then the temp started rising and the red light came on. When I turned the heat on, I got no heat. When I open the hood and felt the radiator hoses, they were cool.

These symptoms are leading me to a bad thermostat, per pinpoint test B4.

I called my local dealership and they told me Ford stopped making the thermostat for the LS. Ugh!

I've seen a few online but there are two different part numbers: RT1154 and RT1254. both are 8575.

The one I am used to has the rounded bottom rather than the flat one.

Thoughts?

 

[Jiwek]

I checked RockAuto. They're out of the aircraft-grade aluminum thermostat housing upgrade, which I was going to recommend (you would find that under the 2000 Jaguar S-type). The motorcraft part listed for the LS V8 thermostat is RT1154 and has the flat bottom, like the second picture.

 

[clubairth]

You can still get the nice Aluminum version on EBay?
Here is one for about $50. You can get them with and without the thermostat.
Search for Jaguar 4.0L aluminum thermostat housing. I find a dozen or more listings.
Jaguar Al. Thermostat Housing
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[Buckie]

@rgorke the pic won't let you see the bottom but this is the thermostat i use in my 06 LS and it's never give me a problem. The OE Motorcraft thermostat was binding itself off when attempting to open. Mine would cycle open sometimes and sometimes it wouldn't cycle at all. Thats why i installed the one in the picture, it has plenty of clearance and will not bind up.