I've got a '95 6.0L, same color as yours. What a great looking car!!

I had similar problems with overheating. I pulled the radiator and had it cleaned and repaired some small leaks if I recall), changed the thermostats, replaced the mechanical viscous unit. Refilled the coolant, bled the lines (up on ramps, etc.), The problem was mitigated but persisted.

I then bought an aftermarket electric fan kit (V12S, which it seems went out of business but I'm sure there's others) and that resolved the issue completely. It's been 7-8 years now and still no problems.

 

Thank you for compliment
Could you please assist on what kind of aftermarket fan did you bought? Is it working constantly or being turn on from the switch like the OEM one?

Thank you!

 

The kit I purchased (March of 2011) was called The Ultimate XJ-S Fan System II Aluminum Alloy XJSREVMIIRAUX, manufactured by a company called V12S, out of Portsmouth NH. It was a complete replacement shroud and fan, very nicely done. Unfortunately it appears they have gone out of business, their website V12S.com links to a TV station. Better Business Bureau gives a report date of August 3, 2017

https://www.bbb.org/us/nh/portsmouth...-0051-92046614

Sorry, that's all the information I could find on V12S. I'm sure there are other aftermarket fan kits out there, perhaps a new conversation would be appropriate.

The fan works on a thermal switch mounted in-line with the driver side radiator inlet (the B-bank, I think). I'm kicking myself for not buying and installing one in the A-bank radiator inlet.

 

V12 S does not exist any more. SPAL are the best electric fans by far; BUT the OEM system, if working properly, will cool the car perfectly.
If the new matrix and thermostats do not so it, do not rule out a faulty (even though new) viscous unit on the fan.
My feeling is that it is a mistake to make any modification to the cooling until the OEM system is working properly. Then you have a known starting point.

 

Heavans YES.

Get that system working as designed, then any alterations you make are easily returned to OE and a WORKING system if what you do is not what you want.

Altering a non functioning ANYTHING is always a doomsday Rabbit Hole.

Been there, waaaaay back before computers and Forums, and even V12's. I was young and knew it all, HAHA.

 

Quite frankly, I'm surprised you ever got the fan! That vendor has not had a good history with the posters on this forum. He may have moved his business to a new name.

 

I totally agree, that first Factory-spec engine should work as it is.
Parts are coming to me from UK and US. Should be here within couple days. I will update with pictures as soon as i will receive them.

 

So, today i received couple options of Thermostats - as described for XJS V12;
Couple questions here:
- C28067 - thats 74 degrees Thermostat - clearly requires drilling a hole for air bleeding;
- EBC3577 - that's 88 degrees Thermostat - with a hole (And a ball inside that hole) - do i understand correctly that this is a bleeding hole and no additional drilling is required?

 

Correct about the 88 ones with th hole. 74 degrees is incorrect, not for the V12. But you MUST chceck that the length between the large rim and the bottom round part is at least the distance that Grant mentioned in his post.

 

I'm sorry for home-kitchen style pictures (My wife was not happy at all as well about seeing Thermostats in her favourite stove.. . ), but:
- 88 Degrees Thermostat - Closed Thermostat length - ±30,5mm
- 88 Degrees Thermostat - Opened Thermostat length ±40,4-40,7 mm - is it OK?
- 77 Degrees thermostat open length - 45mm - is it too much?

Could you confirm it thats within spec?




Gracias

 

The 88 degree one is slightly too short. If you read Grant's thermostat writeup, on an earlier post, 41mm is the absolute minimum open length required, and 43mm is best.
The 77 degree one opens at too low at temperature, not correct for the HE V12.
From post 12 above: "Simple enough to heat them up and measure the open length, 43mm is the aim length, disc to disc."

The problem is that this thermostat is too short when fully open to 100% close off the recirculation ports, thus allowing the coolant to bypass the radiator when it should not be able to. I advise buying the Stant thermostats I recommended earlier.

 

This one with a longer closed length, and so longer open length, would be better, and it is in your part of the world!
https://www.ebay.co.uk/itm/353247603...3ABFBMzsS9jf1f

 

Morning brings better ideas.
Measured once more - this time from Upper disk (Inside) to inner(expanding one) disk (Outside) - 42,5mm;
Previously i've measured from Upper disk (Inside) to inner (Expanding one) disk inside part (As seen in the picture) - i believe that's not correct way of measuring.

 

Good point. They should be OK.

 

The 74 stats are for teh Carby V12, and too cold for EFI engines.

That length as now measured is OK.

Rule #1

Send the wife shopping, that way we can use the stove for whatever, the dishwasher for cleaning parts, etc etc. You have a steep ;earning curve HAHAHA>

Drill that hole, NO LARGER than 1/8" and NO SMALLER then 1/16".

Fit the stat with that hole at 12 O'clock, and note the suggestion for keeping them in the groove whole the covers are slid on, its in that write up.

 

Dear Grant,

Why do i need to drill additional hole in 88 Degrees Thermostat? As seen in the pictures - it's already with a hole (And a ball inside) - i thought thats a bleeding nipple?

I've already replaced them today - see pictures, added two new caps (20PSI and 16PSI), unfortunately cannot test because Heater Box (With AC Evaporator and Heater matrix) is still missing. Matrix is coming, but AC Evaporator is a problem.. Mine is leaking and in a very unfortunate place - cannot just weld it. Tried looking for a new one - no luck
In the meantime i have fixed both Heater blowers - both vacuum solenoids where dead.. - should say expensive fix.

 

BUGGA,

OLD age mate, you will get here one day.

I simply snip that jiggle pin, and then you hav ethe hole.

Now I really a drink, sorry mate.

 

So the same question remains to me - do i have to drill aditional/new hole or modify the existing one in the thermostat (With a ball)?
I thought this "Ball" thing is actually a breathing hole for trapped air itself.

 

You can use the thermostat as it is, and leave the jiggle ball and the hole it is, in without needing to change it. Good luck, I look forward to hearing how it goes.

 

Thank you Greg for your swift response. I've already installed all related parts but currently got stuck with damn AC Evaporator. Mine is leaking and cannot find new part no where thus cannot move forwards assembly for Air Box (With Heater matrix and AC Evap);
For older Pre '93 Jags there are plenty of options but for later models with different Evap piping.. nothing.