Howdy,
It is starting to warm up here (Adelaide summer can get to 44 degrees celsius) and recently I have been caught in traffic for 20-30 minutes with no issues.
The temperature needle has crept up to or just below 1/2 way mark on warm day traffic (26 degrees) when stuck in traffic. The revs are around 750 idling in traffic at stop lights.

My questions are:
where should the temp needle be on the gauge that is acceptable?
should I add a modern temperature gauge for more accurate measure to keep a eye on the temp?
should I replace the mechanical fans with electric fans as a safeguard ?

I will be replacing the thermostat in next week (DT18A purchased).
There will be times where I may have to drive it on warm days in traffic (not 44 degree though!)
cheers Clayton

 

the XJ-6 has an auxiliary electric fan already, the one located under the front bumper. Works very well and it is automatic. Works from a Thermal Sensor mounted to the bottom right side of the radiator.
When the temperature exceeds the sensor's pre-set Run point, the fan starts and does not stop running until the temp is lowered, even if the engine is shut down.

The temp Gauge can register a bit over the center mark and that is still fine..

 

Doesn't get any better than that !

About the middle. As Jose sys, if it goes beyond center a bit, it's no big deal. What you don't want to see is the needle going up-up-up with no end in sight.

I'd wait and see how the car behaves before making any changes.

If there's a problem it'll most likely be a clogged radiator.

My experience is with a Series III. I found that the cooling system will cope with city traffic up to about 32-35ºC. If conditions are hotter than that the coolant temp will start creeping up beyond the center of the gauge and stabilize at the higher temp. Never actually overheated.

All bets are off if your cooling system isn't 100%

Cheers
DD

 

Thanks Jose & Doug , good to know it can handle up to 35C if I'm every stuck.
Having fixed the coolant leak and the carbies, the last few months it has been running well and had no problems.

Jose you are correct , I have a front auxiliary fan in front of the radiator and have seen it working. I have checked it when the air conditioner is on (its not very big though).
Im surprised it works as it looks original (probaly 45 yrs old!).

Clayton

 

small but powerful fan Clayton, enough to keep the XK inline 6 engine under control. Noisy too but mostly reliable. Mine is the original one in the car.

There is an old modification you can do to run the auxiliary fan continuously whenever the A/C system is ON. I did it to my 1984 XJ-6. Works great. However in cold weather you have to disable the mod because you need a hot engine for the heater. What the heck, it works great in hot heavy traffic. And it makes the Jag sound like a Maserati which has fans running constantly that are noisy. Pavement gets real hot in Florida. I'm surprised there aren't more tire blowouts at the speeds people drive here.Tires get really hot.

I have instructions for the mod if you are interested. I imagine Adelaide is very hot too. Never had the pleasure to visit.

 

Ha yes I would like the instructions to make my xj6 to sound like a Maserati!!, thanks

I'm an Adelaide local and enjoy the lifestyle - we have a hot dry heat in summer, great beach / surf weather .
I imagine Florida similiar but not quite as hot and a bit more humid - I assume good beer drinking weather also..
I too have not had the pleasure to visit US, plan to one day.

 

Jose, I'd like to try that mod also please. Having lived with a temperature sensitive S3 V12 E-type for many hot Canadian summers, I'm terrified of an overheat possibility and will do most anything to preclude it.

 

Iramphal, the mod was copied from the V12 as I understand it. Doug would know.

The V12 has two of those aux. fans I think? I do know the V12 fan or fans run continuously with engine running.

Clayton, Iramphal, I will scan the mod instructions and post them here. You will need a Diode soldered or tapped to one of the Red relay wires. The Diode's value will be in the instructions.

 

My lump lives just fine with two brand X E fans. The PCM manages them. usually off except at a long idle or in very slow traffic. it can handles the hottest days around here. Each summer we get a few 100F days. Temp guge at center and at times just a bit right of center.

Because of a small disaester, it has an Electric water pum[. works great.

Carl

 

Thanks Jose

 

As I live in a tropical climate, I did the mod to make the electric fan run any time the A/C is on. However, I found the engine was running a bit too cool a lot of the time. It might be partly as I have a bespoke alloy radiator fitted. So I reversed the fan mod and let the thermal switch turn the fan on as per original design. This has been working fine for me since. The fan only comes on in slow traffic generally.

 

Yeah, Jaguar configured the circuit that way on the V12 for a long time. The e-fan would engage whenever the a/c compressor was engaged. And the a/c compressor was engaged whenever the climate control was used, even on cold days when heating and defrosting was called for. Thus the e-fan ran all the time. The logic was a bit odd. In the late 80s Jaguar began revising the circuit on some models.

FWIW, on my V12 I have the circuit configured so the e-fan is temp controlled only.

As for the two fans, I am not aware of that being a specific V12 feature. I've not seen it...but that doesn't prove anything. I know that early Series III XJ6s had two aux e-fans. Circa 1981-82 Jaguar deleted one of the fans and installed an oil cooler instead. This change may have varied by market; I don't recall. But it applies to the USA cars at least.

Cheers
DD