Jaguar blowing water hose off

[karawara88]

I was driving home today when the coolant low warning came on, then the car overheated. I found a hose had blown off, so I put the hose on again and filled with water, drove home and it was overheating again, this time another hose had blown off. Re-fitted and filled with water and left the car running on the drive. I noticed the hoses were swelling so a build up of pressure is blowing off the hoses, any ideas please.

[fountain]

This is a complete guess. Is it possible you have air trapped in the cooling system? Then when the car gets hot the air expands and blows the hoses off.

[BillyNoMates]

A blockage somewhere in the cooling system ? Most likely places are the heater matrix or the radiator.

Your thermostat could also have failed closed or partially closed.

[qapmoc]

1. - All cars have a pressure relief valve of some kind built in to the water system somewhere to release excess pressure, sound like yours is blocked or stuck, if it is an old model it might be in the cap on the radiator, otherwise it will be in the cap on the water tank.
2. - It should not build up that much pressure normally anyway, when the engine is cool remove the water filler cap and then start the engine and watch in the tank, if there are air bubbles coming continually or the water level fills up and out of the tank then it might be a head gasket leak, if it does not bubble or fill up it might be as BillyNoMates suggested, so then first change the thermostat and try using the car and see what happens.

[karawara88]

Thanks for your replies, In the morning I will do as suggested and check to see what happens when I start the car, head gasket sounds like ����s eek. So I hope its not that. My main worry is that damage has now been done because of the overheating, although when coolant low level lit up the temp gauge did not show overheating until I pulled off motorway.

Its a 1998 Jaguar xj8 so it has cap on expansion tank I will check that as well.

Again thank you for your replies and suggestions I don't feel half as sick as I did this afternoon.

[KebabMeister]

It's looking more towards the head gasket I'm afraid.

[karawara88]

Just a quick update, used a mates card to get the RAC out, he seems to think its the head gasket. :o(

So the question is anyone have experience of changing a head gasket on an xj8 what sort of costs am I looking at. I am guessing its probably better using a Jag specialist rather than local garage.