I just lost all coolant in my 2007 XK Coupe. I was on the freeway and all hell broke loose with warnings. Had it flat bedded home. NOW, where do I start to look for the problem? There were no leaks prior and coolant was at correct levels. I would appreciate any help from all the smart people here. Thanks.

 

Other than to just look for a leak, you could fill the system with straight water and then pressurize it using one of those pressure cap things. If it blew as you say, it should be a pretty obvious leak and easy to find.
Your car wasn't spewing white smoke by any chance, was it?
Also check your oil, make sure it doesn't have any frothy brown in it. That'd be way bad. The dip stick would be sufficient. 100% oil would be good.

 

Thanks for the quick reply. Pretty much what I plan on doing tomorrow. Just asking so that I might concentrate looking in particular places. I just hope that I didn't drive it too far trying to find an exit off the freeway.

 

Remove the cover over the center top of the engine. A small hose that leaves the coolant tank for the top center of the engine, has a simple connecter that falls apart with age. I replaced it with a 3/8" copper plumbing tube. I now have a temp gauge connected to my OBD2 plug.

 

An obvious place to loose coolant on the 4.2 engine, as I found recently, is the coolant hose which runs unseen in the valley underneath the intake manifold. The expelled coolant will either be evident on the top of the bellhousing (beneath the firewall / bulkhead) or leaking out around the rubber inspection bung in the bottom of the bellhousing, or both.

The replacement hose is not expensive and replacing it by removing the intake manifold is not difficult on the normally aspirated cars.

Richard

 

Thanks, again for the replies. Let's see how "obvious" this will be.

 

Well gang. I just spent almost 5 hrs getting the intake manifold off to source the leaking coolant problem. The good news first,I don't see any evidence of any leakage and that little hose looked good, although I didn't really inspect that plastic fitting that Sony2000 referred to. I was so convinced by the replies that the "valley" was where the problem was that I didn't do what I had originally planned on doing, which was fill it full of water and try to source it that way. That's 5 hrs of my life I'll never get back. So now, going to have to put it all back together and go back to plan A. I can tell you, with all the myriad accomanying hoses, brackets and electrical connectors, it was a real bitch getting that all out of the way for enough clearance to get it off. RichardS did mention an "inspection bung" in the valley. I say a black oval piece in the center of the valley that looked like it provided access to the crank case, I assume that's what he was referring to. Again, didn't see any evidence of leakage there. I'm open to any more suggestions from any of you good people out there, of course. Thanks to all, so far.

 

??? You didn't try to replicate the problem and troubleshoot before you tore stuff apart? That's not the recommended way of auto repair.
Dang, you're lucky you didn't do that with an XK/R. That'd have taken you many, many more hours.

 

Now you've got it stripped down replaced the hoses - they are getting old anyway.

 

I know, I know, Cee Jay,I've been working on cars for almost 60 years and know better.....always eliminate the easiest first. I just felt so sure from the responses that the odds were that would be the problem. Never too old to learn a lesson, even one you already new. LOL Yes, McJag222, doing research on what I should and am able to accomplish before reassembling. Thanks, all.

 

At least you now know what's in there - good practice anyway.

 

Yeah, McJag222, at 74, this ain't gonna get any easier. Much easier, even 20 yrs ago. Oh, well, you what's said about "beating" time.............

 

Latest on my coolant leak. It sure was that hose in the valley, upon closer inspection. I've attached a pic of the hose and a closeup of the rupture. Now, does anyone have a suggestion for the best place to source the hose, and does it come as one whole piece with the connecting part and clamps or do you have to buy all separately. Thanks in advance. Doug

 

That's the one where the bigger hose runs into the smaller hose! There already exists a discussion on this. You'll have to dig it out for opinions.

 

While you’re in there…. Change everything you see. It’s all old and will fail too.

 

I'm pretty sure it's one piece - hoses from a Jag dealer are not that expensive - think these are the part numbers probably AJ89093

To VIN B20074 - AJ89093
From VIN B20075 - AJ811763

Also check this:

 

I don't really understand what's going on here.

Firstly, are you running your cooling system on pure water? When that hose splits the valley is coated in coolant, especially when you lose it all as you did, and it would be impossible to remove the inlet manifold and not see the pink, green or blue coolant residue everywhere. Years ago I used to buy colourless coolant but I've not seen it for years and am not sure that it is still available but even then there would be sticky clear residue inside the valley. If you are running the cooling system on pure water without any anti-corrosion additive, your cooling components will be corroding internally.

Secondly, the OEM hose completes complete with the the different diameter sections and even includes the hose clips.



This was my valley after removing the inlet manifold.

Richard

 

There is sometimes a difference between OEM and OE.
The hoses have lasted how long? and how many miles? Thus, I would only source from the dealer.

 

OEM means that the packaging for the hose will have "Jaguar" and a Jaguar part number printed on it. In the UK, it doesn't really matter which retailer you buy it from provided it is a genuine Jaguar part. It might be different in the USA.

Richard

 

Some Original Equipment Manufacturer ‘s may build to multiple specifications; one that satisfies the Original Equipment engineering specification…. and possibly another.

Easily enough confirmed as you have identified, in some cases with the application of the logo and confirmation of the part number applied to the component. Of course, as components are “improved”, new part numbers will be applied. (for example part no. Y supercedes part no. X)

For example, look up the OE tire specification. You will find that an OE tire may be very different from the non-OE version of the very same tire.
(and thus the significant price difference directly from the tire manufacturer)

Cheers.