'97 vdp. I decided to swap out my thermostat and the back gasket was in pieces. The new one didn't come with a gasket so I went on the hunt for one locally and they all want to sell me an o-ring, which I know I don't want. But the gasket on the hose side doesn't show up in any of the parts searches they do. I guess I could make one. One place did have coolant gasket material but I'm surprised that this isn't a common gasket.

 

Do not install the large O - ring

Even if it comes with one

Cracks thermostat housing as you tighten bolts

Sorry I have nothing for the gasket

Which brand of thermostat and temp rating have you chosen for replacement ?

 

Take the thermostat housing to the parts counter. If they're in a good mood and not too busy they can rummage thru their boxes of thermostat gaskets and find a good match....or something close enough to work with perhaps a little trimming.

Cheers
DD

 

It looks like the correct gasket is NBB2217AC, from another thread. I ordered one from Amazon. It's currently in with some gasket goop and holding pretty well, but I'll get the correct part in there.

 

X300 replacing thermostat - Jaguar Forums - Jaguar Enthusiasts Forum

 

Genuine Thermostat And Housing-3.2/4.0 Litre (less 6.0 Litre) For Jaguar Xj 1995 - 1997 (from 720125 To 812255) (x300) Classic | Jaguar Land Rover Classic Parts

Item # 3 as part # NBB2217AC ?

 

Welch out of Ohio USA

I've had good quick service from them

Search ( this link works )

 

The 'O'ring is for the AJ6 engines.
Gasket for the AJ16 engines.

 

Yup, I knew that part thanks to these forums. I've currently got it reassembled with no gasket and there may be a very slight weep, nothing serious. And a new gasket on the way.

 

Weep may change drastically once heated up and pressurizing

I don't know if it gets to the point of boiling in practice

 

No reason just using liquid gasket maker sealant by itself would not work.

that being said, if there is supposed to be a gasket, i would use a gasket.
i used the gasket with also a little thin spread of high glycol resist rtv

 

Agreed if used correctly RTV could replace the gasket (it is called gasket maker after all, in addition to being a sealant). Last two I did I had to make one out of gasket material, tracing the old one with an X-acto knife. Works well, any parts store should have some in the back somewhere, sheets or a roll. Supplement with sealant accordingly.

 

just got to be sure to follow the right guidelines.
when using a small spread on a gasket just essentially to help a gasket stick and remove any tiny imperfections in the surface you just spread it thin on the surface or gasket and then attach and do it up.
you can then also return immediately to service as the rtv is not providing the seal all by itself.

if you are using it instead of a gasket you will want to put a small bead, then you want to tighten the surface only finger tight. this will compress and spread the rtv.
then after an hour or two once it has begun to cure you will come back and tighten to torque spec.
this ensures that you get a nice seal as now at this point the rtv is more like a rubber gasket and will actually compress like a gasket.
if you tighten it fully originally you run the risk of it just spreading out everywhere.
you should also hen wait 24 hours for it to fully cure before returning to service.

YES you could have it work properly by not following the above methods, and i am sure there are plenty of mechanics who just slap some rtv, tighten and immediately return to service but doing it like this may result in you needing to do the job a second time.
and when putting the rtv follow the LESS IS MORE approach.