Thanks Greg. Remove both caps? I could have sworn I read somewhere that both caps were never to be removed at the same time. Something about pressure in the system. I've only ever removed one at a time. Maybe that's why filling it is hit and miss....

I have a 5.3 litre car (1992 facelift model, still with the old-style door handles), so will check the cap specs for that. [EDIT: Jaguar Classic Parts says it's for all XJS model years]. And check the pressure rating of the Merc one that the garage replaced my old grotty OEM one with (for free, so I'm not really complaining). Something in my memory is saying "14 PSI" though I don't remember if that was the cap or something else I read about caps.

This is the hose to remove and blow through, right? Looks fatter than the diagram, but it seems to be the only candidate. I'll try that in the morning, when I give the hoses a good search for signs of leakage by the joints, as best I can.

Header tank hose location

I'll research the location of the thermostat casting nuts, and see if there's anything there, too.

Thanks for all your advice....

 

I'm not quite at that level. Yet. I generally check fluids weekly. Though I check my wallet more often - and frequently need more petrol. I think little petrol fairies come in the night and siphon it away....

 

Quite so! Fill as I described, COLD engine of course.

Yes
On the engine end of the top radiator hoses. Also check carefully ALL the clips on ALL the hoses that go into or out of the inner wing tank and all those joining the radtop bleed pipe at all their ends and joins.

 

Basically I couldn't go wrong if I check every hose clip I can find, right? Will do.
Thanks!

 

You'll find like millions (well not really but you'll think there are millions)

 

Hi Greg.
I checked the hose leading to the atmosphere tank as directed. I can blow through it (it's harder than a straw, as it's long, but I can blow through it), but cannot hear any bubbling of water/coolant. If there is any in there, the level is too low. I'll fill her up using your dual-open technique and try again later.

The Merc cap used on the main filler appears to indeed only be rated to 14 PSI. At least, the numbers "140" are written on it, by one of the sticky-out bits you grip to turn it. There are other numbers, smaller, but they look more like a part number. So it certainly wouldn't hurt to replace it....

I also checked all the hose fittings I could find, but nothing stood out. There is a thin bit of rust-coloured stuff around the top of Hose 6 in the diagram below, but no sign of any fluid there. The rubber all appears in good condition (flexible), and most of the worm drive seals look very new (the one I had to loosen to blow down the pipe was the only rusty one, and that was only surface rust that gave way easily as I turned).

There is what looks a lot like coolant on top of the alternator (?) directly below the filling tube, but as I have spilled some before, that's probably that.

So at this stage, I'm stuck for an obvious culprit, but will start by replacing the pressure cap at the least....

 

Replace BOTH pressure caps. Also look at the heater feed and return hoses carefully.

 

I'm going to replace both (David Manners only sells them in lots of two, anyway).
Which hoses would be the heater feed and return hoses?
Actually, I think this thread discusses their location:
https://www.jaguarforums.com/forum/x...estion-173629/
Anyway, I have bought a ton of premix coolant, so shall add that, removing both caps, filling from the centre cap until the wing-side tank overflows, then adding more until the central pipe is full. I have four litres. It will be interesting to see how much it needs....

 

The heater hoses are easy to find. There are 3/4...

1. Goes from the rear right side water rail to the heated valve on the bulb head (feed)
2. Goes from the heated valve to a pipe located a bit further to the left side (feed to heater matrix)
3. Comes from the bulkhead to a pipe along the left side main chassis rail (return)
4. Comes from the front end of the pipe to the radiator (return)

The one which is most awkward to check is on the radiator.

 

I think I found them all right, Daim. About 15 mm-20 mm thick, right? The bulb head thing is a sort of roundish brassy thing in the middle on the bulkhead? No sign of any leaks, anyway.

Okay, I added about 2.5 litres of coolant. I removed both caps, and added coolant into the centre opening. The wing tank never came close to overflowing, though the centre one did - I stopped when it was pretty much right up to the top (before it widens for the cap) and the wing reserve tank was showing about 10 cm down the pipe (which is an improvement on not showing at all, of course...).

This is the Merc cap. I think that the "140" must mean "14.0 PSI". No idea what else would show the rating.


Level of coolant in main pipe before I basically couldn't add any more.


Level of coolant in side wing tank pipe when the main pipe was full.


This is the only hose joint I could find, doing a pretty thorough check, that even looked as if it might be leaking. I have no idea what it is, however. It's down a fair way towards the front of the engine on the left hand side (port side).


So once I've had a run with the coolant as full as it will go, I shall keep an eye on the temp gauge, and then once the coolant's had time to circulate into the atmosphere bottle, I'll try the blowing trick again....

 

SD
You may have a partial blockage somewhere. The wing tank opening is well below the centre spout opening, at least it was on my car before I did away with the whole multitube thing. So if the centre spout is full and the wing tank is NOT overflowing, it should be. Give the hoses a bit of a squeeze here and there, PARTICULARLY the hose with the questionmark pipe that goes from the centre crosspipe to the bottom inlet on the wing tank. It might be worth undoing this one and making sure it is not collapsed internally. Numbers 29,30,31,32. Any pipe that goes to the wing tank if undone, should be able to be blown through and produce bubbling in the tank.



Greg

 

Hi Someday

The Plastic Cap with the Rippled edges (last photo above) is for the Power Steering Fluid, don't let that run out of Power Steering Fluid. (check once a week)

Or your Debit Card will Self Combust at even the thought of what it would cost to fix it!

 

140 on that Merc cap is KPA, and equates to just over 20PSI, not good.

Also, that cooling system looks terribly gunky, and would explain your temp gauge oddities 100%.

Time for a full flush, atmospheric tank removal from the hiding place, and empty the Kilo or more of mud out of it, and start over.

Might be time for a seperate thread, as this has moved a tad away from the Efan originality, dunno.

 

Hmm. A lot to digest here. Thanks everyone for your comments and advice.
So too much pressure for the pressure cap is also bad? I'll check the pipe Greg mentioned, but I suspect Grant's right, and that the cooling system needs a full flush. Including the atmosphere tank. I'll order a new fan clutch anyway, as they aren't expensive, and get that installed and the atmosphere tank cleaned.
I actually did get the reserve side tank replaced late last year as it was leaking, so it should be a lot cleaner in that pipe. There does look like some crud in the system....

I haven't actually ever checked that power steering thing. Didn't know what it was. I haven't checked power steering on any car I've owned, actually. Though I think it was recently refilled by the garage when they fixed a steering issue, I shall certainly add it to the list of things to check. I assume you just unscrew it and there's some sort of measuring stick or gauge in there.

I'm fine with moving to another thread. Probably shouldn't crowd an e-fan thread with only tangentially related stuff. Would this be better done by a Mod, shifting the entire thing from when I first mentioned the issue? If so, any Mod is welcome to do so.

 

Just a sort of update, as I don't really want to hog this thread too much more. Odd things are happening with levels. I mentioned earlier how I filled it with both caps off, and only managed to get the reserve tank halfway up the spout. So I checked again this morning, after a shortish couple of runs (half an hour each way max), and the main spout, which was full to just below where it widens, was down about 5-7 cm, and the reserve tank spout was pretty much empty. Leaving the reserve tank cap off, I then rechecked the main spout, which suddenly was also essentially empty. Most odd.

So I emptied about another litre of premix into the main spout, and this time the reserve tank spout filled to overflowing. So I capped it off, and added a bit more to the main spout. When I add to the main spout, when the level's so low I can barely see it, there's gurgles and some bubbles, like the coolant is displacing air.

Took her for my usual commute to the university and then back via some shops, making an hour's drive on the return. Admittedly, today wasn't scorchingly hot, merely hot (high of 32 degree, 70-80% RH), but the temps were very well behaved indeed, only going up to a hair or so past the middle marker.

I still want to get the atmospheric tank cleaned and the system purged, however--I don't expect merely dumping loads of coolant in has fixed the system. I've ordered two new Jaguar OEM caps as well (amazingly, I found someone in Japan with them, and for a very reasonable price).

What does make me raise my eyebrow is what's in these photos. On checking this morning, in other words after a short run the day before (when the levels didn't go up equally), I found what looks very much like dried coolant splatters. The coolant appears to have dribbled out of the main cap, then been blown back by the fan. There's also signs of it dribbling out on top of the radiator cover.
Excuse the low quality. These were taken with my tablet camera.


Coolant splatter on engine/aircon compressor, etc.


Clear signs of coolant dribbling down spout from cap. Doesn't appear to have dribbled much farther, however.


Coolant leak on rad cover

Once the new caps arrive, I'll take the car in to get the rear shocks and diff done, and get them to check the cooling issues as well.

 

Hi Someday

Maybe Thermostats not opening, causing the System to pressurize and leak out from the Caps or somewhere else.

Unfortunately not an expert on this but Greg or Grant would know.

 

I wouldn't be inclined to blame the thermostats, as they were both replaced last year. How often do they fail?
With the spout dribble, it's possible or even probable that replacing the cap when the level was just too full pushed some out and I didn't notice, but the one on the rad cover is definitely not from that. May be as simple as tightening the worm gear bracket of course, which I will do.

 

Following up in the original eFan post. Deralle eFan died. 3.3 years old.

 

Bitter experience has taught me that SPAL are the only reliable aftermarket fans for the V12.

 

I have Spals in her now. I understand that what you say is true, but this is my first purchase from Spal personally. I can say that the build quality on these is military-spec-like compared to every other eFan I’ve had. Very nice.