Jaguar S Type coolant too hot

[LOXIT]

 

(background story, not important)***HI Guys, i bought a Jaguar S Type 1999 3.0 last year in January as a project to work on. I felt quite safe as my dad works on cars since a young age and also owns a 2000's Landrover. He is friends with an indepent Jaguar workshop owner who reprogrammed my ECU for free one time. He gives my tipps sometimes but I usually have to figure out things myself, as he refuses to work on S/X Types and therefore hasn't got specific knowledge about them. I worked a lot on the Jaguar as i bought it super cheap and not running. I started going to university and therefore spend less time working on it, so it's just parked in my parents driveway. It's now running but it didn't drove more the 100 meters for almost half a year now, because its not registered***

I now wanted to get it registered but when I start it, the fans run at fullspeed after a few minutes and the temperatur gage climbs up to 239 degree F/ 115 C and sitting stable there (not red area on temp gate). I bought a new thermosthat because the old one was a bit creasy and it didn't open quite smoothly (i tested it with hot water). That didn't change much, but now you could clearly see when it opend on the cooling temp graph on my diagnosis device. My dad came to help me and he noticed that the tube coming from the radiator was cool. We took it off and there was no water inside. We filled the pipe and radiator up from that tube and reconnected it. It now gets hot but nothing changed. We noticed that the radiator is also cool. We bled the system after every step.

If you have any tipps i would be very thankfull. Next i want to run it without the thermostat to see what happens. Sorry for my bad english, i'm german.

[N6 JMX]

Hi Lennart, have you confirmed that the water pump is working correctly? A dry / empty hose would suggest that no circulation is taking place.

Additionally, with an unknown history, you may wish to consider emptying the entire coolant system, flushing the waterways fully and then refilling with the correct strength and formulation of antifreeze. Mixing antifreeze types can create gelling and therefore blockage of the waterways.

N6 JMX

[LairdScooby]

The other thing to check is whether the radiator is blocked as that sounds very likely. Also check the condition and security of the cooling fins in the rad, if any are missing this will compromise the cooling, even at idle in the driveway.

Also worth confirming the correct antifreeze has been used in the past as per what N6JMX points out.

[LOXIT]

Thanks for your fast replies,

To N6 JMX:
I didn't particulary check the water pump but when I bleed the cooling system, the water shot out of the bleeding valve, so there is defenately some pressure. I will flush it completely but first I test it with regular destilled water.

To LairdScooby:
There wasn't any major damage on the outside of the radiator but I will check on the Weekend, when I go home.
How do you check for a blocked Radiator? That sounds promising because there was a lot of sludge on and in the thermostat housing and on the hoses coming from it. The Jaguar wasn't moved for a long time and only run for a couple of minutes when I was testing stuff.

LOXIT

[LairdScooby]

1 hour ago, LOXIT said:

How do you check for a blocked Radiator?

Best way is to check the flow using a garden hose. On any engine i prefer to remove the thermostat and refit the housing then remove the top hose from the rad and insert the garden hose into the top hose - usually a snug fit and then turn the hose on. This runs clean water backwards through the system, exiting from the rad top hose stub so gives a good reverse flush of the system.

As a simple go/no-go test to see if it's blocked, run the engine up to temperature and once the 'stat opens, the top hose should be hot. Switch the engine off and use the palm of your hand to feel the temperature of the rad going from top to bottom. It should have a gradual reduction in temp as you get closer to the bottom hose, any sharp changes indicate there is probably a blockage around that place on the inside.