Hi all,
My 2005 2.5L V6 petrol has a coolant leak, not been able to trace it yet, so looking for advice on which vacuum/pressure tester to buy at a reasonable price?
I don't have a compressed air supply but can borrow one if it would be better than a hand pump

Thanks in advance for your thoughts

 

I may be stating the obvious: But can't you just follow the track of bread-crumbs - or in this case the white residue of the dried out coolant?

Suspect No. 1: The reservoir on top. It is likely to have cracks and the coolant drips thru very slowly.
If though: 2 options: Replace, or smear "liquid metal" onto the areas with the cracks (after deinstallation of the reservoir). Drain at least some of the coolant out of the system by the plastic-bold under/near the radiator before removing the reservoir. If you do it right, you may be able to reuse the coolant (if it is not too old anyway). You may want to fill the coolant back in later via a funnel with a paper-towel as dirt-filter in the funnel.

Suspect No. 2: Plastic bits between the rubber hoses.

Suspect No. 3 - and this is a bit vague, as I might be mixing up Jaguar models here: Normally there is a metal elbow going into the engine somewhere near the "valley" and this elbow would have an O-Ring, which leaks...

Suspect No. 4: Rubber hoses.

Suspect No. 5: But this is more so for the S-Type: Part of the water-pump is leaking as the "wall" is corroded through: That part, which cannot be bought, as it was never declared to be a spare part (only half the S-Type water pump is a spare part (the other half can be salvaged from a Ford, if you are able to find that part somewhere, which is also very unlikely).

 

An example of Peter's suggestion (Suspect No.1) is a photo of the bottom of my coolant tank that I recently replaced, taken looking at the bottom of the tank. That crack cannot be seen from above the tank and, to me, is terminal. I wouldn't trust a repaired tank. New tanks are available on Aliexpress for sensible prices.

 

Yes, my X-Type tank has similar cracks, also underneath.
I also would normally not have considered trying to fix this.
But the PO (previous owner) of my X-Type fixed it - with what exactly I cannot be sure.
It seemed to last. Just to be sure, I put anopther layer of liquid metal over it.

 

A weak point is the plastic coolant reservoir - I had a slow coolant leak and we traced it to small hairline cracks on the underside of the coolant reservoir which allowed coolant to slowly leak. Check it out - it's the most likely culprit if you're having issues tracing the leak source.

 

PCJags, I recommend 2 things for you:

1) get a black light and in a dark room or at night, shine the light into the engine bay. Most coolants these days have a UV dye put ino them. So, when coolant leaks out, it will leave this dye behind and the black light will cause the dye to light up.
2) go to your local auto parts store and ask about their tool rentals. In a lot of cases, the store will have a rental tool you can get that will be all inclusive in pressure testing the coolant system. If your stores are like the ones here in the US, you end up paying for the tool, but when you return it, you get all your money back, aka, free rental.

Like others have said, the expansion tank on this car is the main cause of most leaks. The plastic develops stress cracks from heating up and cooling down. You also want to look at the connector that attaches to the back of the overflow tank (the hose runs along the firewall from centerline to the tank). The other common place is in front of the motor (between the motor and radiator). There is a large T piece that bolts to the thermostat and has the large coolant hoses attached to it. This is a 2 part piece with an o-ring in the middle of it. THat o-ring will deteriorate and cause a slow leak. Getting to it is a bit of a PITA (gotta remove the airbox, then you don't have a lot of room to work as it is tucked up under the support for the radiator).

 

I had another inspiration reg. cooling leak:
This would actually be the most simple explanation:
It is also possible that you do not have a "real" coolant leak:
It is possible that the pressure-valve (integrated into the lid of the reservoir) opened up on purpose, because the coolant was too hot, or simply: The coolant level was slightly too high.

 

HI Peter,

Interesting thought, as I did not mention the car has been standing on the driveway for the last year while I sort the headliner (I know..) and bits, I also lost the only key that slowed me down for a while, so good thought but not for this case I fear.

Thanks all comments appreciated
I was going to add an icon, but thought it may be misunderstood.

 

Did you find the source of your coolant leak meanwhile?

 

I have been lazy, its winter time, the cars in the open and off the road. I lost the only key now that's sorted started the headliner, scuttle leak into footwell and other bits and bobs. Now need to prep for MOT, looks like the front disc's are rusted and all the fluids needs attention, I suspect the water bottle itself and think a vacuum tester will be quickest way to check.

Will update when I do the work.

 

I notice that nobody seems to be mentioning one important thing:

DO NOT USE COMPRESSED AIR TO CHECK FOR COOLANT LEAKS.

 

My question from yesterday above "Did you find the source of your coolant leak meanwhile?" had a reason:

I stumbled yesterday HOPEFULLY into the solution for my engine oil leak, which I am chasing since over a year, putting an insane amount of time into this.
And this "hopefully solution" could also be a possible explanation for your coolant leak...
It is something I never heard or read about, but after I already swapped the read crankshaft seal (ie: transmission off), it was the last straw before having to remove the engine from the X-Type (only possible by pulling it out from underneath) to get to the head-gaskets or the seal below on the short block...
So I just went ahead and removed this "unusual attachment" to the short-block to check for an oil leak there...
I would have called this attachment "water pump housing", but I later found out, that Jaguar calls it the "Auxillary Drive Assembly".
The P/N on that part is 1X4E-8A583-HC, however, this P/N does not assist you in any way. The other P/N, under which you can actually find this part, is: C2S43294.
It is still possible, to buy those new, but they cost an arm and a leg.

So: This utterly unassuming part can be the source of an engine oil leak or a coolant leak, and both would be extremely hard to locate, because this part looks so unassuming that one just does not suspect it... I am going to write a more detailed thread about this part when I find time, but here is the part, which might interest you in regards of a possible source for a coolant leak:

This is the part I am on about: A bot hard to recognize from the backside, which you would never see normally. From the other side it holds the water-pump. It has an "inlet" and 2 "outlets".


This shows the engine, with the "water pump housing" already removed. Marked there is the water inlet and the main water outlet. Both of those are possible causes for coolant leak!


This shows the outlet of the housing cleaned up already and the point where it connected to: not yet cleaned up and utterly rusty. Note that it was extremely difficult to remove the 2 little bolts on the back of the black pipe: I am in Australia - we have only little rust here. In any other country I would have grave fears that you'd break those bolts off in the attempt to remove those... - that is once you get access to them: I removed the upper one with a 1/2" ratchet and a 8mm socket (a spanner would have only destroyed the 6 corners of the hex-head). And tough luck about the lower bolt: Spanner does not work and NO access for ratchet, because the stabilizer bracket between transmission and engine is in the way. I supported the transmission with an additional car-jack and remove the 4 big bolts with a 13mm socket. Then I had access to the lower little bolt on the black pipe. If you see that rust on the black pipe, you will understand that it would also be possible that the coolant simply wander thru that metal pipe, where the rust would have created the first little rust-hole.
Another possible point for coolant leak is obviously a bad seal: I think the P/N is either XR85353 or XR85431 - I am not sure about that...
Also note on the picture above: See the 2 different bolts next to that seal in the little picture: The upper one is the original with the way too small head for this application - I will replace those 2 original bolts with 2 of the kind shown in the lower position: The yellow-zinc-plated bolts with the way bigger head...


And here we have the INLET shown in more detail... Again: That seal is a possible spot, where the coolant could leak. P/N for new seal: C2S11282 (cheap on britishparts, IF you have to order something from there anyway, because the postage costs there are the killer...). However, I think, if the coolant is leaking from there it is more likely the flange of the water-pump-housing that presses (or better: does no longer press) onto that seal: I hope you can see the deep "craters" on the surface of that flange. They would be at least 3mm deep! The material has just been eaten away (electro-corrosion!), and even if the seal there is OK, it cannot seal anymore with those craters in the flange-face. I fixed this by putting 2 layers of liquid metal on there and sanding it flush.

PS:
Of course the coolant could also leak out thru the gasket of the actual water pump.
P/N of that seal: C2S13730, for just 1.02 Pounds at britishparts, but again, due to the killer-postage, this is for me in Australia not an option, if I do not have to order something from there anyway. And: Most other places have ridiculous prices for that cheap gasket - that extreme that the best option from Australia is actually to order the water-pump (C2S18139) incl. gasket (but make sure that the pump comes with gasket!). But as this water pump seems to be the same for:
FORD CONTOUR ESCAPE TAURUS JAGUAR X-TYPE MAZDA MPV MERCURY COUGAR MYSTIQUE MONDEO 2.5/3.0L, MAVERICK 3.0
there is a possibility that (after long research) you find that gasket somewhere for a reasonable price, if it is sold for Mazda or Mondeo, etc.
Let me know, if you found one that way...

So these are few more possibilities to add to the already plentiful reasons for a cooling leak on the X-Type...