www.jec.org.uk

I am considering renewing the thermostats when I renew the coolant but see that two temperature settings are available. What is the thinking here and which is appropriate for a 1978 XJS?

Thanks

I have today fitted an 88 to my 4L car ads the gauge had been reading between C & N now it reads between N & H which makes me wonder if a 82 maybe worth a try?

Michael,

You should have an 82 Deg 'stat in a UK 4 litre car.


Peterjohn,

If no-one comes back and gives you the answer before tomorrow, I'll go and look it up for you.


Paul

Paul

"You should have an 82 Deg 'stat in a UK 4 litre car"

That's interesting.
When I replaced my stat I fitted what I thought was the correct Jaguar part - EBC 3621 as per the Parts manual (and Classic Parts) for all 4 litre cars, I'm sure from memory this was an 88 degree stat.
I know that early 3.6 cars were fitted with a 82 degree stat.

Where is the 82 deg. stat specified and what is the part number?

Tony

Tony,

Some confusion here (caused by Jaguar!).

The Service Manual says that the 'stat opens at 82 deg.

However the Tech Spec says 88 deg for both 4 litre and late V12s.

Having just spoken to Michael who has bought EBC3621, it is actually stamped 88 deg. So I think that the service manual is incorrect, perhaps a carryover of text from the 3.6 manual. It also apparently shows a pic with the jiggle pin at the bottom whereas it should be at the top.

So, I would concur that the 4 litre stat should be an 88 deg one.


peterjohn, I'll look up the early spec for a V12 for you.

Paul

peterjohn77,

I understand why you might not know whether to fit an 82 or an 88 'stat. It seems that most early V12s were fitted with 82 degree stats, particularly those with emission level B (which is UK spec). However, later UK cars all seem to have 88 degree stats fitted as standard.

So, I might be wrong but I think that a UK 78 car would have had an 82 degree stat fitted (and the early service manual says that the stat should open between 79 & 83, which would imply an 82 stat).

So what should you fit now? Well, the 88 stat would theoretically give slightly better fuel consumption. If you've got any problems with the cooling system, then an 82 stat would encourage more flow through the rad.

I hope that helps somewhat , but I guess you've still got a decision to make.

Paul