My coolant system has burst two hoses. Must be clogged. Plan to drain coolant system and flush with cleaner then refill. But I also need to replace a burst hose. The first burst hose was easy enough (see picture) but the second hose looks like it goes down into the belly of the engine. I need to identify the replacement part and learn what needs to be removed to replace it. For good measure I also plan to replace the thermostat.

I seen some posts and videos but they don't seem to get to the issue of the smaller burst pipe that goes down into the engine. Can anyone point me in the right direction?
Any help is greatly appreciated.

 

#1 hose appears to be a Right Valley hose and #2 is Radiator hose to coolant tower on a post 2003 4.2L engine. Guessing your car (not Listed) is a a (4.2L 2003-2006 XK8) PS, Was not aware of the yellow clip to secure that joint?

 

It is one of the two 'valley' hoses (heater feed & return). The one you've highlighted is part # AJ86326, the other is NNE3946CA. - Replace them both, together with the tee piece NNE3944BA 'while you're in there' as you will need to remove the inlet manifold.

Consider whether the octopus (MJA6728AC) should be part of the job if the hoses are starting to let go.

 

something else beside the coolant hoses - look at your upper sock mounts - those should be perfectly centered - you will need to fix - you could try to recenter them but looking at the orange material, it is most likely they will fail sooner than later so I would recommend replacing with the @cjd777 @baxtor solution -

 

I would be very surprised if your system is clogged. A water pump circulates coolant and only slightly pressurizes it. Normally your cooling system becomes pressurized to ~14psi each time the system heats up. This intentional pressurization allows engines to run at higher, more efficient, temperatures without boiling the coolant. However, as hoses age and become weak, they will eventually burst from that pressure. It is good practice to replace every bit of hose at the same when this starts to occur. Otherwise you are playing whack-a-mole replacing old failing hoses as they sequentially fail on you.

The other common source for increased coolant pressure would be a head gasket leak, which is a much grander problem.

 

I had a truck retread (piece of tire) smack my XJ in the grille and wreck the cooling fans on the highway long ago and had to have an emergency repair on the road. They replaced the radiator and the fans, but the fans were not working (blown fuse I think) and that caused a couple of hoses to burst or pop off especially when not moving. Just a thought on bursting hoses.

 

>look at your upper sock mounts - those should be perfectly centered - you will need to fix
Thanks for your reply. Funny you mention that. I replaced the mounts a couple of months ago, Maybe 600 miles ago. The old mounts I replaced about 5 years (15,000 miles) ago. Both times the ones I pulled out were totally shot with the inner piece floating freely. These latest new ones were quiet for about two weeks then the noise, when going over bumpy road, seemed to return. They last more than two months, right?

 

Let's hope so

 

John, did you save the old ones?
If you will send me a set, I'll fix your frequent replacements. You can PM me and also read what Steve (member baxtor) and I have done to improve this very problem.

 

@cdj777 I'm still trying to fix the hose, but yes I did save the old ones. I'll get back to you when I finish the hoses and coolant flush.

 

With the age of the car you need to change all the hoses. They are just shot because of time and temperature. Otherwise you will get into what you have now. You will continuously go back into the car to replace each individual hose as they fail in turn. Plan to replace all rubber hoses and do it at once to minimize the labor involved.

As posted above it's not clogged.
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Thanks @michaelh for this post. I got the part I needed. I may get and replace the other hoses, but I'm going to take a look at them first and see how hard it is to remove the inlet manifold. Now. How hard is it to take off the inlet manifold on this 2004 XK8? Can you link to anything like instructions?

 

The reason I am thinking the system is clogged is because the hoses failed one after the other with five or so miles between. I assumed the likelihood of that happening unrelated to any other problems with the cooling system is very low. Can you elaborate on why you don't think it is a clog?

 

John, this should get you started and lots of how to do it in the first section of this Forum.

How to remove the intake manifold and replace the heater hoses (with photos) | Jaguar Forum

 

Get an 82 egree thermostat rather than the 88 deg ..This will give you a head start in traffic and hill climbs

 

You may well be able to finagle that particular hose through underneath the inlet manifold, although it looks like it's already had the end cut off and stretched back to fit.

However, you can't do that with the other as the connection goes into the block at the back of the thermostat tower. I strongly recommend that you do both, and that you source the correct 'cobra' hose clamps.

R&R of the intake is laborious rather than difficult. I've attached a snip from JTIS showing the procedure, although it's not the best text, IMO. it may help highlight any differences from the video that cjd777 has linked to.

On my early car, the throttle body elbow is also separately attached to some brackets on the block - the attached snip doesn't mention them so it may be different on your car.

You will also find access to the octopus is much better once the TB is out of the way

 

To replace the hoses, I'm removing inlet manifold and having a lot of trouble removing the fuel injector electrical connectors. So far I have broken 4 connectors and one latching wedge on an injector. So I'm evaluating my life choices.

They are not original. Here is a page that shows the part on a parts website. The part has two movable pieces. An inner black one and a red one. The red piece hooks to a wedge on the injector. The black piece is somehow used to unlatch the red piece, but I don't know how. I can't seem to get anything to move at all.

Does anyone have experience disconnecting these? Is there a trick?

 

The red lock slides straight back. Now you can push down on the black tab to release the connector. Noticed how the red piece in your picture is pushed in and is close to the black piece? That's the locked position.
Here it is in the unlocked position from your link.




The picture is a bit dark so hard to see the black tab but it's there.




See if that will release it.
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Note: Solved. Please don't respond.
Second Correction: Apologies to anyone who spent any time on this. I found the other port part so both holes are accounted for. Please disregard.
Correction: I just need information about the smaller port. The larger one is accounted for.

So I finally got the inlet manifold off along with the throttle body attached to it (had to buy impact tools, order parts). I see a couple of holes one hole on the throttle body that didn't have anything attached to them it and I'm wondering what they are it is and if I need to do anything about it?

Here are some pictures of the unconnected ports:



Removed manifold with throttle body attached.

Closeup of unconnected ports.
Any ideas?

 

Based on my 2002 4.0 XKR experience, that small port you circled in red with the o-ring, appears to need need the attention of a C2S15816 Brake Booster Vacuum Hose Connector Kit.
Hopefully someone more knowledgeable than I concerning your XK8 will step in and verify. I would hate for you to lose your brake boost!