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Hello,
well looks like that this problem of diminishing coolant level in the coolant tank is not fixed completely.
I got coolant tank fixed (but not replaced), one of the main coolant hose replaced with a brand new (it was leaking heavily from there).
Anyway I am losing about 1/4 of tank every 200mi. Things got better because before the fixes I Was loosing all the coolant
in the tank after 50 miles.
I do not see leaking anywhere anyway apparently.
Could the engine be eating coolant ? (engine going to die). Car has 71000mi.
I do not have overheating problem. Engine goes up to almost 90C
only if I am stuck in heavy traffic or going fast uphill for long time.
It went to about 93C only one time on August when outside there were 110F and I Was stuck in traffic for 20 minutes on the freeway.
So not sure what it can really be...
Engine is running fine, a pleasure to drive it. Very seldom (2 times in 4 months and I do drive this car) I had a sudden loss of power and rpm going down for about 10 seconds then it recovered. After I changed the fuel filter this did not happen anymore so far.
Anyway I am concerned.
I am investing money and time on this car, it looks good, it drives fantastic with new shocks but, well I am concerned about this coolant level going down thing. Perhaps should I install a new coolant tank ? does not look cheap to do.
Last edited by xjfourty; Dec 12, 2017 at 10:57 AM.
Later XK engines suffer from head gasket failure, which can account for the loss of coolant.
After a cold-soak, preferably overnight, pressurise the system with a tester then check for any external leaks. If none are present, it's most likely the head gasket has failed.
A couple of ways to see if the engine is 'eating" coolant.
1. Get a tester for hydro carbons in the coolant. Or visit a shop for that.
2. Remove and examine the spark plugs. If any coolant is getting into the combustion chamber, it will "steam clean" it.
3. Check the expansion tank behind the outer front left head lamp. And the hose connecting it.
4. Make sure your pressure caps are good and on the "correct" openings. I've forgotten which is which.
the pression cap is worn and old, I ordered a new one... it may leak from there but I did not find any obvious evidence of that. The car was manufactured on 11/83'
A quick check for head gasket failure is to check whether there is any pressure in the cooling system when the engine is stone cold, (there should be none).
So remove the pressure cap in the morning after the engine has stood overnight and see if it releases any pressure. However if all seems OK, I'd still get the coolant tested for combustion gas products.
If the car is an '83, I would not expect HGF at 71k miles, as it will have the slotted block, (or should have !). This prevents the previous syndrome of block cracking between the bores which lead to HGF in previous engines.
Another thing to check is pin hole leaks in the radiator, I had that a year or two ago on my truck. Fluid escapes but evaporates on the hot radiator, leaving a deposit on the radiator (looks like a small insect is nesting). Doesnt leak when cold and unpressurised and you find yourself topping up coolant with no apparent leaks. Check both sides of the radiator for any irregularities.
You could be losing it out the overflow, for a fair while when I got mine I was overfilling the expansion tank and losing it there(thinking I was losing coolant every couple of days). I let it lose what it needed to then monitored the temp gauge religiously for quite a while and it behaved and the level never got lower than half until the head gasket blew.
Since the new engine went in 18 months ago the only time I have added coolant was when I replaced the water pump.
Possible leaks, possible head gasket, as others have mentioned.
But.....
Are you overfilling the system by chance? If you are, the excess will be pushed out, giving the impression that you have a problem.
If you haven't already done so, try NOT adding coolant and see if the level stabilizes.
Cheers
DD
Agree. On my 1980, it had the steel tank and instructions in the hand book were to only fill it from cold to about halfway or less. It should definitely not start full when cold or there's no room for coolant expansion.
so I checked the expansion tank, that's not the problem, replaced the expansion tank cap with new genuine Jaguar one.
What happens is after driving the car for a dozen miles, when I stop everything is ok, no leak. After 20 to 30 minutes it start leaking coolant fluid. On the left side, driver side. I do not know what can be. Leaking is usually something like 1/4 of tank capacity.
Could be a bad water pump ? Why is leaking after a while it is idle and not when I am driving the car ?
Coolant leaks can be sneaky. You're just gonna have to out it in 'leak mode' and start looking at all those hoses and water pump....and hope a drip or steam presents itself. Sometimes a leak will leave a telltale stain....below the water pump, for example.
Give the hoses a gentle twist and jiggle....and pinhole leak might be revealed. Wear gloves.
If nothing concrete shows up go around and tighten all the clamps just on GP. You might get lucky with an easy fix!
Have you checked the drain plug at the back of the block on the left behind the dipstick near the engine number. I was checking and rechecking everything at the front of the engine.
I found it accidentally when checking the oil I a saw a drip out of the corner of my eye and went searching for the leak. It drips straight onto the exhaust pipe below and evaporates making it hard to detect. But there were tell tale signs of coolant stains below the plug.
Have you checked the drain plug at the back of the block on the left behind the dipstick near the engine number. I was checking and rechecking everything at the front of the engine.
I found it accidentally when checking the oil I a saw a drip out of the corner of my eye and went searching for the leak. It drips straight onto the exhaust pipe below and evaporates making it hard to detect. But there were tell tale signs of coolant stains below the plug.
Clarke, that body is still visible under the engine. You really have to bury them, not leave them laying around. Specially in the Brissie heat.
Clarke, that body is still visible under the engine. You really have to bury them, not leave them laying around. Specially in the Brissie heat.
Dr Phill stops for nothing, he was probably getting things ready for the new engine while I dropped that one on the floor and got the new on off his ute. Had the job done and test drive within 11 hours.
OK I tracked down the problem. Fluid is leaking from expansion tank tody I could see it clearly. Now which expansion tank should I get? There is one which is sold on amazon. Anyone can give me a hint? Also is it easy to replace yourself? Thanks
Eating coolant fluid ?
