XJ needs to be moved after 20 years... help please


I got mine from Lidl, so it really did not cost much, if it works even a few times it will be worth every penny, or cent. :laughing:


The wire for the shifter light gets a Real workout, flexing every time the shifter is moved. Mine was broken when I got the car, had been “repaired” before, I suspect more than once.

That wire needs to be very fine and flexible. As it’s only a small bulb, it doesn’t need to be very heavy gauge, merely Very flexible.

I thought a coiled shaver wire or something like that might work, and it did!

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Good morning. I have been away from the car for about 3 weeks. I was dreading opening the garage because I figured there would be a giant puddle of god knows what on the floor. I was happy to see that everything seems pretty dry. Of course there are some leaks but only ONE tiny spot under the transmission actually made it onto the floor. I think if things were to stay like this I would be ok with it. After all its a Jag.

I figured I would start with something easy. I have no high beams working. In fact all 4 high beams were burned out. I salvaged the 2 H4 bulbs from the parts car. The H1 are in fact all broken on both cars. What does that tell me? I also noticed the inner H1 only get about 8,5V (engine off). Seems a bit low.

Somehow every little thing turns into hours of work.

I also had to drill out the fixture for the lower blinkers. They were so far gone. I opted for these Allen head that fit perfectly. I know this is not original but I think I will be ok.

So I went back to the garage and found the thermostat housing of the parts car. I had to really fight one of the long bolts to get it out but eventually it gave in. Looks like both cars had a 82C thermostat. I have been wondering if 88 is better than 82. I don’t know. Also I do not really understand why my current thermostat seems to be stuck open. I checked it with water and it opened and closed fine.

So yesterday I took the second thermostat into the kitchen and played with it. My laser thermometer seems to give funky readings with just water. Maybe a reflection issue. Not sure what to make of it but it also opens and closes smoothly. I suppose I will save the 20€ and install this one. I really hope I do not have to do it a third time…

Very slow progress with the winter coming…

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Hi Max,

Usually it tells of bad connections, in my experience 99% of them being bad earth connections, but for the headlamps also the headlamp relay and fuseboxes are suspects, the good news is that as already Series 2 XJ’s were offered from the factory with Halogen lamps the setup does include a (Hella) relay, unlike earlier Jaguars like the E-types and Saloons where there was no relay for the lamps, just a switch (with a heavy current.)

When debugging lamps etc (especially in my old and rusty MKV DHC) I always take a black wire coming directly form the negative (or in the case of the MKV, posivite) battery terminal and compare the results until I find where in the path from the lamp, relay or other component the voltage drops and /or resistance goes up.

Typically in all XJ’s the earth connection to the bonnet form the extra high beams has broken and the lamp tries to find earth via some other route.

Have fun! :smiley:


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Another thing to remember Max is to make sure you do not hold the bulb by the glass and if you do then wipe it clean of any contaminations from your fingers.

I am wearing latex gloves…

Are they clear gloves??


ah yea you got me there…HAHA
This was in the kitchen. I had already figured out that this one was broken. I though it to be an odd place to burn out.


This is a design problem.
Cables go from the battery to the ignition switch, after all the way back to the front fuse box, and then to the lights. Lots of meters of tinny cables, connections and switches, all contributing to voltage drops…
Best way to fix this is to install relays. It really makes a difference.

But as Pekka said, check that you have good earths and connections.

I use 88°C.
If your cooling system is in good nick, engines work better when warmer.
IMOHO, a lower temp thermostat is just a band aid for a failing cooling system.

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Broken bulbs simply mean they are broken, Max - ohm to verify. They may have blown because a PO applied too high voltage, or simply shaken or ‘worn’ out…

Connections should read battery voltage (check). All wires, except ‘active’ ones, will read battery voltage irrespective of whether they are badly connected - it is current flow that drops voltage through wiring and connections.

The 88C thermostat is ‘better’ for the engine, and was originally fitted - the engine likes ‘warm’. Some use lower temps for other priorities - it’s an arguable point; and more a matter of personal or preference and arguments…:slight_smile:

Malfunction of the thermostat in-car when working OK in a water bath is unusual - and difficult to confirm. The IR thermometer aimed at the water surface, bur not roo close, should indeed read ‘correct’ water temps…

xj6 85 Sov Europe (UK/NZ)

Well, since the car was originally used in Spain, maybe it was given a lower thermostat rating to prevent overheating?

My lighting was very good without relays. I put some in because the fuse box had failed and it made a tiny improvement… almost unnoticeable. I used a large enough supply wire from the battery direct. Probably not the best of my wiring back then but a good improvement for reliability in my case.

Unless I notice that the lighting is terrible I think I like to keep it as stock as possible.

I made 2 ok looking front fog lights out of the 4 that I had. They seem to accumulate water and rust through. Unfortunate design I guess. I can see how one of the glasses was broken. They are pretty low!

You got lucky on the thermostat bolts, known to snap, not just on XJ, but virtually every vehicle I come across

This might be an opportune moment to mention I am an anti-seize enthusiast

Especially with dissimilar metals, but really everywhere unless there is a really good reason why not

I see all these Youtubes were they struggle with stuck components, then put them back together bare

Years from now, someone will be thanking me for anti-seize on some vehicles I sold

My '43 GMC I had to torch or grind off nearly every fastener, spent hundred$ on SS fasteners, used nickel anti-seize

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Yea. I have learned to go really slow when I see a bolt that is “ready to be a PIA”… Lots of caramba and patience is key.

I virtually lube every bolt and screw with something before it goes back. Not sure if it will last +30 years but I am guessing it is going to last longer than petrol cars will be allowed around this place…


One of the best and cheapest upgrades I have ever done! I was going to do this to Tweety before I sold it, but never got around to it. I did do it on Harvey, and it made a visible difference, and it was easy to do.

Emphatically, Dutch - the only way to avoid overheating is adequate cooling…:slight_smile:

The thermostat can only fully open for max circulation - the rest is up to the radiator. Whether at 82 or 88 is sort of immaterial - engine, properly cooled will stat at that temp…

Generally, as you imply, the cooling effect relates to the difference between the air and coolant temp - and the air flow. The greater the temp difference the more heat is dissipated - so at 88 more heat is dissipated than at 82. The main argument is that at light loads and/or low speed the engine generates less heat - so running at 82 there is some ‘reserve’. When engine load increases, coolant temp rise as a larger margin before it becomes critical…

But the temp rise is unavoidable if there is insufficient cooling…:slight_smile:

xj6 85 Sov Europe (UK/NZ)


Very true, but I have seen this before.
For markets with higher temperatures, lower temp thermostats have been used…

My V12 runs nicely at 90 degrees celcius. Goes there quickly and never exceeds 100.

Verzonden vanaf mijn Galaxy

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My car is a German Car and the parts car is a Belgium car. Not sure that requires a 82 at all. yet both had them. No way of knowing if that was a jaguar call or not. I have to assume my cooling system apart from the thermostat is working good as it stayed at the low temperature even with 35c OAT.

So I pulled the thermostat today. Much easier now that everything was properly lubed. Since I could not get a perfect read on the other one I decided to play with both of them and compare. Indeed the one I had installed (left in picture opens earlier and is also closing much slower if you pull them out and let them cool down. They both start to open before 82 but as you may be able to see is that the on on the left is already over half way open at that point. I will install the one on the right and see how we do. If I do end up buying one I will get the 88C but for now I will try this. Also I will this time pay attention for the air whole to actually be on top. It was at the 9 o clock position when I pulled it.

Coolant was still green but going towards brown. I had hoped it would look better after all the flushing I did. But I guess I cannot deny this being a 30 plus year old engine.