www.jec.org.uk

Hi
I have bought an upgraded metal thermostat housing/tower. ( I have a slight leak where the moulding for the coolant hose has broken/become brittle)

Do you need to remove the inlet manifold to replace it?

I have read that an 8mm crows foot spanner will do the job.

Any advice or instructions would be appreciated?

Thanks
Craig

Its the rear two bolts that cause the problem. They are well buried below the front edge of the manifold.

Egged on by Mr Jenner, I hot bent a spanner to slightly less than 90 degrees. That done the job is fairly straight forward. Suggest you grab the oportunity to change the thermostat at the time of fitment. Note the bleed off jiggle pin goes at the 12 oclock position.

I`ve run an ali tower now for over four years. It is identical in dimensions to the old plastic type so fitting is easy. However, it has one design issue which did not transfer well from plastic to metal.

You will find the tower has a very sharp edge on the top of the threaded cap portion. The cat away land on two sections of the thread is very destructive to the rather inappropriate conventional o-ring that comes with the new tower. Aalthough a torque figure is given, I found the O-ring would slip off the top of the tower when the cap was tightened. Numerous leaks occurred and I then tried a bit of thickish rubber mat as a complete circular seal which fitted in the cap before fitment. That worked for a while and I was never happy with the arrangement.

Finally I changed the seal to a red fibre washer which has never given further trouble.

I wrote a full article about fitting the V8 tower in our magazine around 2010/2011 in the S-type Forum pages. More on this job can be found here on our Club site if you go to the S-type BB and cgot to the Cooling section. Loads of pics there which you might like to have a look at.

Mike

Many Thanks Mike for that. Appreciated.
I will have a look at the photo's and article you mention.
Kind Regards
Craig

hi Mike I have been looking at old posts regarding changing the thermostat tower, I am considering changing the two troublesome bolts for cap head to make access easier, they look like M6 , do you happen to know what thread they are .
thanks Tony

They are metric but I`m not at all certain of the thread pitch.

As regards changing to cap head screws, the height of the cap head may, or may not give an issue with clearance. It must be nearly ten years since I changed that tower on my old S-type. Details have gone fuzzy.....

Mike K

Be careful as visually it’s easy to mistake the thread pitch. For a 10mm bolt
If it’s screwing straight into aluminium I’d hazard a guess it’s 1.5 mm pitch. The other finer pitch is 1.25mm.
8mm bolt is 1.25mm and 1.0mm
So I would remove them and take them with you to a supplier who can match them up.... or buy a thread guage.
Not teaching ‘grandma to suck eggs’ so to speak but don’t strangle them up as it’s very easy to strip the alloy

Hello Tony,
Good idea to change the thermostat housing you never know how long they have left as they older.
The original bolt is M6x25 Jaguar Part No C2Z1354 and has an 8mm reduced hex head.
The torque setting is 10 nm.
It is a Metric Course Thread and the thread pitch is 1.00mm.
Have attached a chart for reference: As DaveNeedham suggests if you have the old ones out take them to your supplier to match them up.
When I changed mine I went for allen bolts and used a ball end allen key to get a bit better access.
To get the old ones out I released the intake manifold bolts(did not remove them completely) to lift it up a bit to enable me to remove the back two bolts.
Hope that helps and good luck
Take Care.
Andy

hi Mike I have been looking at old posts regarding changing the thermostat tower, I am considering changing the two troublesome bolts for cap head to make access easier, they look like M6 , do you happen to know what thread they are .
thanks Tony

Not sure if you have done this yet but if you check out the thread here " coolant fans running " i did do a little write up and pics of a tower change. Just that it is under cooling fans !!!!

I am about to tackle this job as mine is now leaking, what is the consensus on either lifting the inlet manifold or using a crows foot spanner to access the rear 2 bolts?

Andy,

I did similar many years ago on my x308. I can't remember all the details but 2 things stick in my mind:

- it's definitely possible to do it without removing the inlet manifold. But I did heat up and bend a spanner to specifically access those 2 bolts.
- part of the problem in dismantling is that those 2 bolts are quite long. They can be cut down a bit and the threads tidied up before re-installation

Good luck

Paul

Thanks Paul, I prefer to not lift the inlet manifold as I'm pretty sure it has never come off before and as it is 26 years old the chances of getting a good seal when replacing it must be pretty slim.

So, finally got round to this today. Those 2 bolts at the back of the tower are tricky, much swearing required...
I did eventually mange them without lifting the intake manifold, by heating and bending an 8mm spanner, as others have done. However, still very fiddly. Once the bolts are loose I found it easier to remove them completely using long nosed angled pliers, slow and laborious process though. I am hoping that cures my leak...

Well done, Andy! Fortune favours the brave!

Paul

Glad you got it done without any issues.
Take care.
Andy