Mystery Heat Shield Part

XJ-S
1

O.K., after a hiatus of several weeks now, my tech buddy and his helper have been at my place working once again on Superblack to finally get her up and running. They have made great progress on her the past two days, and are about to finally reach the happy ending (hopefully). :joy:

We did find the source of the power steering fluid leak and, oddly, it turned out to be the low pressure (i.e. return) hose, not the high pressure (i.e. feed) one. In fact, the high pressure hose was in great shape, possibly even having been replaced recently. The leak in the low pressure was in the form of a split in the hose, but otherwise it looked to be in O.K. condition. However, the heat insulation sleeves over the hoses looked pretty ragged, so we replaced them with a pair of high-quality aftermarket (cut-to-fit) ones made by ACdelco.

One stumper that we ran across though was what appears to be a small piece of metal, either steel or aluminum, apparently part of a heat shield assembly. Itā€™s flat and slightly rectangular, maybe 8" x 6" or so, with a few holes in it for mounting screws/bolts. My tech discovered it just laying loose in the engine compartment not far from the p.s. hoses. :open_mouth: Lucky it hadnā€™t fallen out onto the roadway, and no idea why a tech would remove it and leave it like that, although we wonder if the PO/seller maybe did when he was searching for the source of the leak. We cannot locate where this piece is supposed to go, though. Anyone have any idea on that? :confused:

btw, a couple of notes in r/ring the p.s. hoses. One is that the p.s. rack did in fact have to be lowered (one horizontal bolt at each end + disconnecting a steering linkage piece on each end) and the front left road wheel removed to access the hoses to disconnect/reconnect them. Also, although my new high pressure replacement hose was properly configured, the replacement low pressure one was longer than it should have been, on the non-connector-fitted end. My tech will simply cut it to fit like the old one (which either the P.O. did likewise, if the hose had been previously replaced, or possibly our new one was incorrectly configured.) by chopping off about a foot of same.

Next steps are to fill and bleed the p.s. fluid system (btw, why do the front wheels have to be in the air to do same?). We will then connect up the new battery and lower her to the ground to very slowly drive her around a bit with lug nuts loosened to hopefully break the front passenger side road wheel loose from the hub. Will then put new brake pads on both front sides and she should be ready for test driving. :crossed_fingers:

Will update more later on.

2

Paul,
You didnā€™t mention what engine is in your 1992 XJ-S, but if it is a 5.3L.V12 then that piece of metal is the heatshield for the power steering hoses, Jaguar part number C44979. Do you have a Parts Catalogue for your car? I found that part on page 1F 02 of the Parts Catalogue for my wifeā€™s 1990 XJ-S convertible.
It should be fastened to the studs on the forward left hand exhaust manifold in a LHD car like it was at the factory. It is a bit challenge to remove and replace the power steering hoses with that heatshield in place. My guess is that whoever replaced the high pressure power steering hose removed that heat shield and didnā€™t put it back where it belonged. I replaced all three of the power steering hoses in both of my V12 Jaguars myself and know first hand that getting those hoses and the heat shield in place properly can be challenging. But, that heat shield is there to protect the power steering hoses from the extreme temperatures of the exhaust system and should be installed properly for safety reasons. The power steering hoses sit very close to the exhaust downpipes and without that heatshield in place damage to the hoses can occur.

Paul

3

Paul the wheels need to be off the ground because you need to turn then from lock to lock to purge the air from the system so having them up reduces the strain on the system.

4

Need photos really. I have some heatshield knowledge after removing them all from my car to clean them up and repair a couple. And when I say ā€œallā€ I mean the steering rack ones, the gearbox massive one (with 2 attached smaller ones at the sides) and the ones that hide the propshaft.

I havenā€™t done the ones at the back yet.

Though my car is a 76 V12 so there may be some differences but I think the heatshields are similar.

Malc

5

My tech finally found where it went and put it back in place. :relieved: I think he said it does in fact protect the p.s. hoses, the low side one, IIRC, from the exhaust manifold assembly. Thanks though.