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Jag V6 running hot?
40inches - 31/5/16 at 01:51 PM

Only running in garage at moment, but it seems to run very hot. The fan cuts in at 92degrees and never switches off.
The temp gauge shows a constant 95-98degrees, and the rad never gets hot!!
On the face of it, this doesn't seem right, however I found this section in the JTIS.

"Thermostat
The thermostat is located in the thermostat housing and allows rapid engine warm-up by restricting coolant flow through the radiator below 82°C (180°F).
The thermostat also assists in keeping the engine operating temperature within predetermined limits, for 2.5 or 3.0L engine the thermostat begins to open at 88°C - 92°C and is fully open at 102°C
When the engine is cold and the thermostat is closed, coolant flows from the water pump through the engine.
It then returns to the water pump through the upper coolant hose.
When the engine is warm and the thermostat is open, coolant flows into the radiator through the upper coolant hose.
It then returns to the water pump from the radiator through the lower coolant hose .
The cooling fans are operated at slow speed when the engine coolant temperature is at 95°C and are operated at full speed when the engine coolant temperature is at 105°C."

Would it be better to fit a lower temp stat or just set the fan to come on at 105degrees? Do all modern engines run at these temps?


froggy - 31/5/16 at 07:11 PM

Most modern stuff tries to keep close to 100c for economy and lots have e electronic thermostat control . Lower stat will work as my 1uzfe wanted to sit at 95c so found an 82c star and it sits in traffic nicely rising to 88 where the fan switch is triggered .


40inches - 31/5/16 at 08:52 PM

Yep, the S-Type engine doesn't have a coolant sensor, and the electronics can keep the engine safely running, even after catastrophic coolant loss Lower temp stat I think


froggy - 31/5/16 at 10:29 PM

They run a returnless fuel system as well and the sensor on the rail can gum up but a few taps sorts it , a good mate is a jag specialist with lots of handy info if I get stuck . Are you keeping the cats and 4 lambdas ?


40inches - 1/6/16 at 08:36 AM

quote:
Originally posted by froggy
They run a returnless fuel system as well and the sensor on the rail can gum up but a few taps sorts it , a good mate is a jag specialist with lots of handy info if I get stuck . Are you keeping the cats and 4 lambdas ?


No cats, and just one Lambda. It's on a Q plate, so no emission test
Fitted a 2.5 fuel rail with a swirl pot and fuel reg, just setting MS2 for fuelling.
Description
Description


froggy - 1/6/16 at 09:12 AM

I've got a complete 3.0 manual in my yard destined for a future project . Seem to be pretty indestructible .


laurencedawson - 6/6/16 at 09:05 PM

Hi chaps,

I'm looking for an engine fir my next project-
Replacing the engine and gearbox in a lotus excel
For a modern v6 or v8.
I was thinking of the jag v6, bonnet height is an issue,
Also it would be for road and track,
Any thoughts?