Oh dear...leaking coolant from two locations
 

I noticed a low coolant message yesterday morning. I filled the empty reservoir and noticed a quick "drip" from a small hose at the front of the engine.

Unfortunately I had to get to an important meeting so I drove the car keeping a close eye on the dash for the coolant message (and using OBD to monitor the temp). The return trip was about 45 mins each way.

This morning I checked the car again to see the low coolant message was there again.

On closer inspection I noticed coolant on the ground, back of engine, under the car. I suspect there must be two leaks or something more sinister going on.

I'm just waiting on an appointment to get the car in to the mechanic but thought I get any input from people here.


https://cimg8.ibsrv.net/gimg/www.jag...3ec603cf33.jpg

There is a small pool of coolant here and beneath the car.

https://cimg9.ibsrv.net/gimg/www.jag...f2c0544d4d.jpg

The [now] broken hose at the front of the engine.


Damn.

Hard to say on the first pic but could be either octopus hose or the feed hose for the heating to the octopus hose.

The snapped pipe is a bleed pipe. They do tendiere to crank off with age.

Thanks Daim,

I've been search around the forums and found this thread: https://www.jaguarforums.com/forum/x...nt-leak-84929/

Seems I could be in for a large bill! :-(

If they do have to remove the SC to get to the hoses - is there anything else I should get them to do while it's apart? My XJR has 228,000km and I'm unsure of it's history pre 190,000km.

Might as well replace all the rubber at the same time. So heat er hoses blubb... Maybe thermostat as they like to break. And maybe service the supercharger...

Thanks Daim, I've only recently replaced the cooling fans, radiator, thermostat and water-pump but it was still overheating - maybe one of the hoses was restricting flow.

Make sense to replace hoses.

Service the supercharger...hmm...sounds costly? :icon_greedy:

Just means fresh oil. That is it...

I know what you are doing... My car wasn't overheating but still needed lots o'money to get it all repaired. What started as a tranny repair job ended up with engine out, loads of parts new etc.

I stuff around €2000 into the rust bucket since March and that doesn't include body panels I have here!

Hi,

Before you're tearing apart the SC etc, fix the broken hose first and have a look, if that fixes your issue.
Pic 2 shows a (broken) bleeding hose (to the expansion tank) and it's possible that the escaping coolant is running into the engine V (which begins right under the SC) and forming puddles there. Then it's spreading all the way to the back of the engine where it runs down the tranny bell housing. And that might be the reason for having coolant on the garage floor at the back of the engine.
That's was exactly the experience that I made when my coolant inlet hose was leaking (see pic, part no. 6). Same symptoms for the valley hoses having a leak in their front area.
So there's a good chance, that you've got only one leak.

Otherwise it's either a leak around the coolant inlet assembly of the engine (the assembly on the engine top but under the SC, where hose no. 6 is connected to) or the valley hoses. There are not much more other possible sources of leaks which allow forming coolant puddles in the engine V.

Cheers, Alexander

But if you have to remove the SC, I'll chime in again with some ideas on what to renew, since I had been down that road twice ;-)

Hi Alexander,

This bleed hose appears to attach to the top of the expansion tank - if this was the only problem how would it account for draining the entire expansion tank?

By the way, this appears to be the replacement part: https://www.jaguarclassicparts.com/au/part/MNC4582BC


Troy.

As the coolant temperature rises, the coolant expands which generates up to one bar of pressure in the coolant system. That's the reason why you never should open the expansion tank cap with tje engine not cooled down yet.
And this pressure causes coolant being pressed out of every present leak and will empty the expansion tank. No matter how small it is or where it is located.

Okay, that makes sense then :-)

Seems like I'm going to have to wait a little while for this part. It's a shame this bleed hose doesn't have standard connectors - but I guess with the pressure involved it's a better design to be factory built.

I broke that exact same line on the bypass when I did my chains and tensioners. Mine broke flush inside at the 'O' ring and I didn't notice it until I fired it up. https://www.fcpeuro.com/products/jag...-xjr-mnc4468ad
...at minimum you have a part number.

Hmm, I'm not sure that's the correct part - this is the correct part I think:
https://www.jaguarclassicparts.com/au/part/MNC4582BC

Your correct, I prompted the wrong one on my detail, ...apologies. There's a couple on eBay for almost half the price... https://www.ebay.com/sch/i.html?_fro...582BC&_sacat=0

Hey Alexander, I replaced the broken hose and all is fine! In total, it cost me AUD$30 - so a good result! :icon_toast: