hallo, does anyone knows the operating temperature of this car; Should it have a thermostat opening at 82°C or at 88°C.
At what temp should the electric fan start and when should it stop.
(having probl with incorrect temp gauge)
Thanks for an answer!

 

Either thermostat rating is OK. Keeping the engine running at thermostat rated temp is another story and not always possible....and not necessarily anything to be worried about.... within reason. The engine really doesn't care if the coolant temp is 82º, 88º, 95º, 100º.

What's more critical is that coolant flows through ALL parts of the engine. Lack of proper flow, more than outright temperature, is what's most likely to hurt the engine.

Obviously the engine should be at least as hot as the thermostat rating. Broadly I'd say that 82-95º to be normal, expected operating range. If you're in Las Vegas in August it might run hotter. If you're in cold conditions it might well hover right at thermos temp, if the cooling system is in good shape.

I believe the coolant fan switch triggers at 94ºC

Cheers
DD

 

Thanks fr yr answ Doug. How can i know if ALL parts are cooled well? (I evacuated the air when replenishing coolant wit the left Wheel 20 cm higher.).

 

If you are confident that all air has been purged, and the system is clean, you should be OK. Optionally, if you feel the need and have the interest, there are modifications that can be made to ensure proper and equal coolant flow. Search "Lutz mod" on this forum or the internet.

One clue that you still have air in the system is if the temperature gauge fluctuates a lot while driving. Another is your heater not producing hot air.


If you left the bleeder port open until you had a strong steady stream of coolant gushing out you should be OK. If you were seeing spurts and dribbles, you still have air in the system.

Cheers
DD

 

Adding to Dougs words.

This might help a tad.

V12 thermostat fiasco explained.pdf

Bleeding the V12 cooling system.pdf

 

No V12 here, Grant, as you know, but the first PDF is a Very Good explanation of how/why thermostats work in Any application; and why, on the farm when we chucked the thermostat on the spray rig, it still overheated.

Also explained clearly to me for the first time, is the reason for different types of thermostats, which no one could ever do to my satisfaction.

I learned something new reading these! It's all clear to me now!
Thank you!
(';')

 

Slick, huh!!!


The engine creates heat. The cooling system seeks to transfer that heat to the atmosphere.


The thermostat neither creates nor dispels heat. It's primary function is regulation, but only in one direction. Assure adequate temperature for optimum engine performance Allow drivability on start up from cold. And assure enough temperature for the heater in the cabin.


Some say, it also slows coolant travel speed so as to allow time to transfer heat in the radiator. Some say, not so.


Yippee. I had not fired up the Jaguar during our "heat wave". No AC in it. A bit of respite today. It fired right up, so as to allow me access to my tools. This AM, began "summer" awaken process for the venerable Honda powered Craftsman SP mower. Oil change, fresh fuel, "power" wash....


Carl

 

Carl, I've always understood the *Reason* for the thermostat, but I didn't know some engines had that bypass mentioned, which when blocked by the *Proper* thermostat forces coolant through the rad.

That explains quite a lot!
Light bulb moment actually.
(';')

 

Interesting. But yr talking "HE"; mine is preHE (sorry should have mentioned); does it also has a bypass?

 

Yes, the pre-HE engines also had the bypass type system

Cheers
DD

 

Yes, except the carby cars, they be special.

Your header tank is different, or was, as was the radiator bleed pipe arrangement.

Still the same basics in all other areas.