Car overheating after HVAC hose busted!-RESOLVED!!!
 

Hey guys, its been a while since ive been on here and thats a good thing! But last night i was driving on the highway at about 80-90 mph and after a bit i began to smell antifreeze burining, when i looked at my temp gauge it was at the hot! I got off the highway and let the car cool down. I found that the small HVAC hose that connects to the heater hoses on the drivers side rear of the engine bay burst. I took the old part off that was still on the tube, and cut the burst part off and stretched the hose a bit to refit it back on and refilled the antifreeze so i could drive it home, but the car continued to overheat. I noticed the fans werent coming on, it never overheasted before last night. Any ideas? 1996 XJ6 LHD. thanks guys! the pic\link below is of the hose that burst.
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Air still trapped in the system?

I had the same thing happening on a BMW 7 (E32) some years ago. Didn't notice it for some time, as I was on the highway doing 130 kmh and the wind flow was enough to keep the engine cool. Pulled off the highway and drove the last few miles home, before the temp went up. Took maybe an hour to drive the last 2 kilometers, as the car kept overheating. Almost each and every drop of the 13-14 liters of coolant was gone!

Once the damaged part was replaced, I refilled and burped the system and everything was fine again. Took some time, though, to regain trust and not keep looking at the gauge every few minutes :-)

If the fans are not running then you may have an electrical fault.

Jaguar did a recall and changed the fan system so they run all the time the ignition is on.

If it got that hot, I suspect the thermostat is toast, they do that.

The header tank pressure cap is also a suspect.

The fans NEED to be sorted, coz if they, or the sensor has failed, then all will be lost again.

Sometimes a "sudden pressure loss" as in a hose busting releases the pressure in the system very quickly, and mud and gunk is basically sucked up and out, but some also settles in the remaining coolant and clogs the radiator, due to coolant flowing.

Thanks for the responses guys. It's definitely the fans not turning on that's causing the overheating issue, thermostat is in working order. So I've checked all of the fuses in the car, every single one and found none to be bad. I have checked the TSB's regarding the fan and don't have the issues described or one that I feel could be remedied by the bulletin. The fans stopped working after the hose blew and antifreeze got everywhere. I checked the relays behind each headlight and both sides look dry and so does the cables leading to them. Any other things I should check? I really appreciate the help as this car has never overheated!

Try supplying the fans with a direct power source and see if they run.

If so you know there is a power issue.

Check to see if power is getting to the fans

Is there an easy way or preferred way of supplying power directly to the fans mike? THANKS!

If you follow the wiring from the fans it should go into a plug or fuse box.

You can take a live feed from a fuse box or the main input cable to the fuse box, get a length of wire with an in line fuse and connect it to the positive wire to the fans.

If still not working then try a new earth to the fans and switch ignition on and see if that solves the issue.

Ok I jumped the fans and both work with battery power. What's the next step?

The next step to find out why the power isn't getting there with the ignition on.

I think it's going to be a fuse, have you checked the ones in the heel boards under the back seat?

Recheck all the ones under the bonnet.

If you have the manuals have a look at the fuse box layouts, then with a multimeter you can check each side of the fuse for power if it's only on one side then the fuse is shot.

If no power either side then the issue is further back in the wiring

Thanks mike! I checked the fuses again and all of them are good and the proper amperage. I took a light tester and touched the top of the fuse on each side and the bulb lit up each time so electricity is definitely getting there it would seem.

OK, so do you have a 12 volt test lamp? Meter? The test lamp is the best for this kind of test and they cost almost nothing.

So the issue is between the fuse box and the fans.

Could be a broken wire, the only way to test is get a pin of some kind and stick into the sheath of the wire at various points until you get no power then work back until you get power, mark that point then continue until you get power again.

Then cut that section out and put a new piece in.

Or a fan relay!

So I took the relay out and jump terminals and was able to get both fans to turn on. Does this mean it's definitively the relay?

Ok so I wired both fans directly to the battery with a switch so I can turn them on each time I am about to drive so that I can atleast have a car until I figure all of this out. Now after driving it still overheats! It takes longer since the fans are engaged. Any ideas? Help please!

Relay is looking to be the culprit for the fans, most likely cause of the overheating is an air lock.

On some vehicles it is recommended to raise the front of the car so the air goes to the highest point, you could try that

Ok someone else told me about the airlock. This may also cause the issue with the fans not turning on I'm told. Does that sound right? And how do i rectify the airlock issue?

Keep the expansion tank cap off get it up to normal temp and hopefully the air will be expelled.

...while the cabin heater is on full high temp.