Can anyone tell me what this is and what it attaches to>
Thanks

 

what model Jaguar is it? To me it looks like a vacuum hose.

 

That is the heater pipe. Attaches to a nipple on the back of the water pump, and then runs to the metal piping that goes behind the engine to the heater core. The open nipple beside your finger in the first photo is the return from the heater core.

 

Mark 1 3.4 engine.

 

Isn't that the vacuum port for the brakes and someone has added a "T" for something ?
Where you are pointing in the second photo, that would go the the vacuum reservoir to the check valve, and from there to the remote brake servo.

It's too small for a heater pipe.

 

Jeff agree with too small. Not at the library but did the 3.4L saloon (AKA MK1) not use a vac. driven window washer with a push button on the facia? If so that is likely the one way valve to the bottle. The tube seems most likely the vac. for the booster.

 

Thanks, It does look like a vacuum piece. It might become more obvious once the engine is in the car.

 

Jagboi is correct. That is where the heater pipe should run via a support bracket. Always used to rust through which is why I fitted in stainless steel. The diameter does look too small. I think someone has had their fingers in there. This is the S Type set up. Let me find a Mk2 diag.







Mk2 heater diagram (sorry I keep forgetting we are talking Mk2 derivative 340) Item 34 or vacuum line below diag.




Mk2 vacuum diagram: (item 10? likely) ~ If so now you must find your heater pipe. They should run one above the other. ~ heater pipe above IIRC.

EDIT ~ I notice Peter says they run next to one another. That too would make sense. That grubby larger diameter thing in the background is the heater pipe at its bend.

 

There are two pipes running side by side along the right hand side of the engine block. To eye, they aren't very different in diameter. The one closest to the block (item 34 in Glyn's second diagram) is from the heater to the water pump. The other (item 10 in his last diagram) is the vacuum line from the top of the bulkhead end of manifold to the one way (check) valve on the vacuum reservoir for the brake booster. In fact, the first photo shows the vacuum take off from the manifold. On my car, there's no T, but it's a logical place to connect anything that requires vacuum, like a vacuum gauge.

I didn't know the MK1 had a vacuum motor for the windscreen wipers. Ford used them a lot. They were laughable; except when you put your foot down to overtake in the rain.

 

It's too bloody cold to go out to the garage. Heat pump running at a comfortable 24 deg C inside. I thought my S type had the pipes one above the other but I'm not going out to check. In any case it's irrelevant. Thanks for resolving that Peter!

 

The MK1 has a two speed Lucas DR3 electric wiper motor ie the same as the MK2.and S type.
The silver button on the dash controls the vacuum system for the windscreen washer pump.

 

I recommend you give this engine a high pressure steam clean unless this is your donor engine.