Guys,
I could use a hand here please. Good news I found my coolant leak, a slow drip that only occurs under the hottest temp or highest pressure. Yesterday I removed the throttle body. And got a good look.

Thanks to Tropic Cat, I have a good picture of the area. If you open the attachment please see the area enclosed by dashed lines and labeled #1. There is the one hose that has 4 orifices, one of which goes vertical into the coolant overflow tank.

See the 1 hose clip in the bottom left corner of this dashed trapezoid? Its leaking at that connector.

I'd been reading about norma connector headaches, looks like this hose only has 1 norma right? BTW is this hose the octopus hose i read about? I can't find a part number for it.

Here's where I'm at. Its Friday before a holiday weekend. Any thoughts on the simplest fastest way to fix this?

Think it could just be a defective hose clamp?

Could I get away with buying 4 inches of heater hose same ID, then replace the end by the leak with barbed connector and hose clamps?

Thanks guys. I sure appreciate it. I'd love to be able to get her back in action today. All ideas welcome. Anyone know the part #? I can't find it in SNG catalog.

John

 

Oops better picture

Follow up for reference. I just visited jaguar parts. I can't find the patt number because its not sold separately. You must buy everything encircled under #1 together.

The part number is: MJA6728AC

The price is $265

Well, given the price, plus a 5 day delivery, I've decided to replace the plastic piece joining these 2 hoses with somethingfrom the plumbing store. As I think about it the drip only under pressure sounds an awful lot like a crack in the black plastic anyway.

So now just need to find pliers that'll get in there to release the clamp, figure out the ID of the hoses, buy a piece to join them and decide whether to reuse the clamps or buy a couple of screw tight clamps.

 

Hi John,
Yes, that is the (in)famous octopus...

Do you mean the clamp I've circled below?
If so, note the part it locates to (red arrow) is a non-return valve. These can crack and leak.

 

Yes sir Michael, thats exactly what I'm talking about.

Am I stepping into a pit of vipers replacing the non return valve with a brass pipe same diameters? That non return part caught my eye.

John

 

Hi,
I'm not a scholar of fluid dynamics, but I *think* that you'd be OK as a temporary measure, although I suspect it would affect the car's heating. May not be an issue during the summer. Others more sage will jump in here.

It's pretty busy tucked under the firewall, so - for the sake of a TB gasket (if you can get hold of one easily) - you will do yourself a favour by removing the TB to do the job.

I see the part has got pretty expensive: it's nearly doubled in price since I last replaced mine, That was in 2012 so it's coming around again for me

 

Thanks Michael!! Don't worry the throttle body is already out. Hey in case you all wonder, the gasket is only $8 from jaguar.

Any other thoughts /knowledge on this plastic 1 way valve are welcome!!

If anyone knows of a way to buy it separately. Please share.
Thanks,

John

 

If a new octopus doesn't work for you right now, the only thing I can think of is the one-way valve in the heater/auxiliary/air conditioning water pump hose MJA6739AC, although that's around 1/3 of the cost of the octopus.

Do you have a breaker within reach?

 

Thanks Michael. I was just in denial;-).

Looks like I'll be tracking down an octopus package. I'll pull the valve tomorrow, hopefully I can get eyes on the source of the drip.

John

 

John, I think I saved the check valve when I replaced my hose a couple of months ago. I'll check later this morning if you're interested, but I think the smart move is to remove the intake manifold and replace the valley hoses and the octopus at the same time.

 

^^^ What he said. I just did this recently. It is a PITA, but eventually it will need doing. Might as well check out the aux coolant pump to, as well as the other rubber hoses to and from the throttle body. On mine the check valve didn't leak, but I was able to replace o-rings the (2) norma connectors to hold out for a while.

 

John, I like RJ's idea. I would do the octopus hose and both valley hoses if they have never been changed. Seems when you fix one coolant leak and new one will pop up. If you do these 3 hoses and also replace the plastic T that is on the left side under the throttle body. This will take care of all of your hard to get to hoses and give you years of not having to worry about these. It sounds like a major job but it is not really that bad. I guarantee you it is easier than working on the front suspension.🙂👍

Good Luck,
Bob

 

The OEM octopus comes complete with new clamps.
Do replace the [biodegradable] plastic tee as BobRoy suggests. Someone in the accounts dept. missed a trick as it's only around $5. NNE3944BA

Good luck!

 

John,

One more thing, if we haven't already given you enough, change the thermostat tower to aluminum if it hasn't already been done. It's a piece of cake with the intake manifold off.

 

Bob,
Actually you made my day - I can finally say: "Already done" to both aluminum thermostat and the valley hoses (ha ha :-) + the reference to the front suspension good perspective.

RJ, thank you so much, you know what I'm going to buy the octopus kit. Why tempt fate, but I really appreciate your kind offer mate.

Jimmy, good checklist, thanks.

Michael, thanks for the part #. We appreciate it!

Yikes, it looks like I'm driving a super sexy toyota highlander for a few days (sarcasm - don't worry i haven't gone over the edge yet ;-)

John

 

I sell plumbing supplies so if you supply some pics and dimensions of the non-return valve I may able to suggest a suitable replacement.

something like this might be suitable

 

XKOwen, great idea. I just got it out.

I bought an expensive hose clamp tool, was worth it! Thank God I took a photo of the valve a few days ago - almost another jkenny don't do this moment - I proudly got the valve out looked at it and realized I never kept track of which side points which way. Close one :-)


It is 3.5 inches long, 3/4 inch OD (so hose is 3/4 inch ID).

Yes she's a 1 way valve. For future reference: coolant flows starboard to port (aka towards driver side USA vehicle.

Any ideas welcome! Plenty of plumbing supply around here.

John

 

If you had gotten back to me yesterday it would be on the way. I don't know if UPS office is open tomorrow but I could stop after my trip to the gym in the morning. Just PM me your address and it's yours.
RJ

 

If you have a cable type hose clamp tool you can replace the octopus with the throttle body in place. I have wrapped the right side Norma connector with a heat shield to protect it from the residual cat heat after the engine is shut off.

 

I think the backflow preventer valve in the octopus/spider hose is the same as the aux system hose to the heater core. I have both hoses lying around in the shed so I'll check. I expect you can find some plumbing part that will fit but I'm not sure it will survive the temperatures under the trans tunnel for very long so I don't recommend going that route.

As far as what to remove to replace the octopus/spider hose it depends on what condition the rest of the heater hoses in the car are in. If the hoses under the intake need replacing too I recommend removing the intake and doing these hoses at the same time. It will make removing/replacing the octopus hose a little easier. If the auxiliary system hoses need replacing (or have never been replaced) I recommend removing these while the octopus hose & intake are also out. When I did these hoses I did the octopus by itself. Then I did the hoses under the intake by themselves. Then I finally did the aux system hoses. I now realize I should have taken them all on at once instead of trying to do them in stages. The octopus hose interferes with the aux system/aux pump when you try to insert it under the fire wall. It's not much trouble when removing it but it causes plenty of problems when you try to put the aux system back in. Removing the intake makes removing & installing the aux system a whole lot easier. It may not be necessary but you need plenty of clearance while twisting and tugging on the aux system. The only way to replace both hoses under the intake is to pull the intake so you may as well do these while you're at it. If you have the plastic thermostat housing the best time to replace it with an aluminum upgrade would be with the intake out, so you may as well have at it.

I realize it seems daunting to go after the entire heater/radiator hose system at once but I discovered it was a mistake to tackle things separately. The parts cost was part of the consideration on my part but mostly I was overwhelmed by how much of the engine bay needed to be disassembled just to replace a few hoses. I felt more comfortable doing one thing at a time but that turned out to make things harder than they need to be. Just my 2 cents.

You might want to replace the 2 throttle body heater hoses while you're at it. I don't have the part numbers with me but you can check with SNG Barrett or one of the other on-line jag parts dealers. Don't go by the part numbers indicated by the model year for these 2 hoses. Apparently there are a few part numbers for these parts and they are VERY different from each other. I ended up with the wrong hoses for these 2 for my car based on the model year alone. The guys at Barrett helped me get the right parts from pictures of the parts off my car.

 

If I understood correctly, the one-way valve in the main loop is to avoid a situation with the engine at low rpm, i.e. low flow from the water pump, producing less water flow than what the auxiliary pump can push to the heater core. Without the one-way valve, the now cold water off the core would be recycled instead of getting hot water from the water pump.

The one-way valve in the heater core loop is to avoid hot water going into the core in the summer due to simple convection as these hoses are not far from the cat converter and other hot parts.