Hi all I have a problem with my XJ8 3.2 auto 2002 year the top coolant hose has blown off twice even after I fitted a new Clip .The problem I have is temp gauge goes up to the red and no sign of fans running so far I’ve checked the fuse and it was blown I replaced it and started car up and temp went high again and no fans working but fuse is ok so I’m after any ideas on what to do next thanks 🙏

 

check your thermostat first, sounds locked up and why your building that kind of pressure in the system to blow the line. How soft is that top hose?....if its old and spongy then it will slip out of that hose clamp.

This is a Honda, but as the guy says, the principals are the same for testing. Open circuit testing is all it is and simple...the 1st 8 minutes covers basic procedures. For his test on the fan relay switch, take one of your wife's glass containers and microwave the water to boiling and put the sensor in it and that will tell you if the sensor is good or not also. Since that guy is at his shop, he did it his way.

 

Thanks for reply I’ll get that checked out

 

You may have more than one issue. A blown fuse is probably because one of the fan motors is bad or a wiring harness going to the 2 motors came dislodged and rubbed thru on a pulley.

The infamous plastic water pump impeller on a steel shaft when hot can slip on the shaft and cause the engine to overheat. Get the water pump replaced with a metal impeller. Problem solved.

If you have the plastic thermostat housing, get it replaced with an aluminum one and a new thermostat.

 

Today the garage phoned where my jaguar is and said that there was no thermostat on the car they said probably last owner knew .Ive owned the car for two years they said to me it’s not looking good maybe engine trouble so I’m not sure if this is right or what to do next .They said they will see if water pump has been checked tomorrow

 

Compression test will reveal all.

 

It is possible that the thermostat was removed in an attempt to solve some overheating issues but thermostat removal does the opposite - it causes overheating. A thermostat must be in place - have a new thermostat installed, then checks should be made whether the engine is really overheating and why.

 

The blown fan fuse should be an indication of what’s going on. I hope the garage looked into that.

 

Water pump checked all blades present and pump works but problem is pressure builds up quick and still overheats and fan fuse blows

 

If the shop said pressure builds up quick, that’s a strong indicator that combustion gasses are present in the cooling system. They need to perform a block test. My guess is that whatever is causing the fan fuse to blow was the issue of why it overheated.

 

If a fan fuse blows, then the problem is probably in the fan for which the fuse is. Fuse 12 is for RH fan and fuse 14 for LH. Does the fuse blow while the fans are at low speed (I guess not) or when the fans are, at higher engine temp, switched to high speed? When at low speed, is one fan spinning faster than the other? It is possible that the fan in question is partially seized or has shorts in its windings causing overcurrent. Check whether the fan that is blowing its fuse can fairly easily rotated by a finger (disconnect the battery before this test).

As for the pressure build-up, with the engine cold, remove the expansion tank cap and start the engine. Look inside the tank for gas bubbles while the engine is idling and when you briefly rev it to 2500-3000 rpm. If you see gas bubbles coming out, and a lot of gas bubbles and/or the coolant in the tank rising while/after revving, then it is the head gasket(s).

 

If there are two small lines from the expansion tank, they should cross at the tank.

 

Thanks all for help so far I’m not sure what the last reply means on the two lines from expansion tank .But I will ask the garage to test to see if the block is ok they said they have done a dye test which was ok .So should I ask them to fit a new thermostat as there isn’t one on the car and also a new water pump and coolant then see if any difference to start with .Then fan blowing fuse will probably be separate issue I’m not sure if he can swap motor off other fan to try for now as I haven’t a clue I’m just trying to get old girl fixed

 

The two lines close together at the coolant reservoir sometimes get connected to the wrong outlets, it is easy to do because the correct way looks to be crossed, but isn't. This is how the lines should be connected, and where they go to............

 

Oh great thanks for photo 👍

 

As I mentioned before, you MUST have a thermostat in place. The mechanic should install one without you having to ask him.

When the engine reaches the operating temperature, the thermostat opens the coolant flow through the radiator. In addition, when the thermostat is open, it closes the bypass path for the coolant directing all of it to flow through the radiator for cooling. If the thermostat is removed, the path through the radiator is permanently open but the bypass path is also fully open. The open bypass will cause about 50% of the hot coolant that exits the engine to flow back into the engine without being cooled by the radiator resulting in engine overheating.

 

Well I called the garage and they haven’t done anything to the jaguar this week they said that they think the worse .So I asked them to refit the water pump they took out last week and to fit a new thermostat and fill her up and I’ll collect her on Monday so I need to find somebody to take a look at her are there anybody on her with contact in my area South Wales valleys

 

Love the explanation, "...haven't done anything to it...but we suspect the worst". Hell of a statement, must have mechanical telepathic abilities. I believe you are doing the right thing to find someone more attentive.

Check the regional section for additional help... https://www.jaguarforums.com/forum/regional-34/

 

I’m going to have new water pump fitted and thermostat but then I need to get fans working is there anything I can try or check out .I know wear the fuses are but anything else

 

From post #4:

You may have more than one issue. A blown fuse is probably because one of the fan motors is bad or a wiring harness going to the 2 motors came dislodged and rubbed thru on a pulley.