Just purchased 1991 jaguar sovereign. Issues

Hello all, I just purchased a cream puff 1991 xj6 sovereign. Currently has 39010 miles on it! I put about 250 miles of it myself. I use to have a 2000 xj8 and 1989 xjs v12, I am excited to learn about the different quirks of this xj40. It has only been driven 10k miles in the last 20 years. Has had the SLS shocks replaced with conventional shocks in 2014 and water pump in 2014 or 17 have to check records again.

Here are some issues I noticed if anyone can help me out and recommend how to fix.

-coolant expansion tank cap leaks. Cap looks good, tried tightening it some more, I believed I overfilled it first but after searching the forums I filled it to the bottom of the white piece in there. Very minimal leak now I say but I can still hear a slight hissing from the cap after running Is that hiss normal? Or is air trapped? I “burped” the top radiator hose.

-every time I press the brake pedal the brake warning light illuminates. I have the “pad” warning with vcm check. Brakes work fine. When parked and pressing the brake the brake light illuminates. also the anti-lock light illuminates for a moment if I time the vcm press right I can get “fail” message to pop up.
-when pressing the brake pedal the brake accumulator shakes/jiggles like it’s about to explode. Is this normal? Or is it going bad?
-my brake fluid level is about a inch below the max fill line. The manual says to fill it to the max line, could this be causing my issues?

-car shut off on me randomly while driving, lost power steering can’t remember if I lost braking or not but the battery light and also the transmission light was illuminated. Coasted to the side of the road and car started immediately afterwards and drove home no problem. Scary???

-weird gargling noise coming from the backseat area? Not from outside or underneath car so ruling out the exhaust. But I can hear it from inside the cabin. Is fuel tank behind backseat? Pump going bad? Normal?

-annoying rattle coming from steering column, the trim covering the under side of steering column. Is this common? Any “real fixes” or do I just tape it? Haha

Thanks you for the help in advance! Is there any books comparable to Kirby palms book for xjs for the xj40?

Hi Steven, The PAD warning light is most likely just worn brake pads and you will have to replace the sensors at the same time. Sometimes you can get the PAD warning if the cable from the sensor is accidently damaged or from a poor connection at the plug where the sensor connects to the car, but I’m guessing, seeing as you haven’t mentioned any leaks the fluid level is low due to the worn pads.
The fuel pump is in the tank which is directly behind the rear seat, so that could certainly be a source for the ‘gurgling’ noise you can hear, and also maybe the cause of the sudden shut off, especially if no error codes were displayed along with it. 39000 miles is incredibly low for a 29 year old car so it has obviously spent a long time sitting around and could be suffering from the effects of stale gummy fuel. First thing I’d do is change the fuel filter and while you have the pipes disconnected flush some clean fuel through the tank and see what comes out in a bucket. If it looks clean try the car with the new filter to see if the noise has gone, if not you will probably have to pull the tank out and investigate the pump.
I’d try a new seal on the header tank cap or even a new cap, but keep a close eye on the coolant level until you are confidant there are no other issues.
Unless a previous owner has dropped something by accident into the bottom column casing, or the screws have worked loose I’ve no idea what could cause it to rattle.


I would advise flushing and replacing all fluid including brake, power steering transmission, etc. There was an issue with the fuel pumps before 93 if my memory serves me correctly. The issue creates a miss. I found out about it after I replaced the leaking tank in my 92 Majestic with a loaded new /old stock gas tank.

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THank you for the quick responses! I will investigate more once I have time. It seems to me the xj40 has less info available compared to the xjs platform.

The gargling noise I mentioned is definitely coming from the back seat area fuel tank. I assumed the fuel pump is inside the fuel tank but was told is is actually external from the tank?

Today the car shut off again while idling In The garage as I shut the bonnet. Immediately restarted and drove around for about 30 mins at the end of the drive while taking a slow turn you could feel the car hesitating and wanting to shut off but kept going. Was not able to replicate after trying for another ten minutes. No codes on vcm at all.

The car was almost at E when I bought it so I already ran half a tank of new fuel In it so I don’t think there is any old fuel left In The car

You need to refer to the car using the VIN number rather than the date, that way we can identify things like whether or not it has an internal or external pump etc.
The XJ40 changes quite a lot through the production years and cars first registered in 1991 could easily be 1990 or early 1992 models. The last 6 digits of the VIN are really the only way to know what you have.

I like to put that info into my profile as well as quoting it in the initial query. Just an Idea.

Hello Steven - since you said the car shut off, in the garage, when you closed the bonnet, have you attempted to recreate the same condition - with the bonnet open, the car idling in the garage (for about the same amount of time as before) and then close the bonnet to see if once again the car shuts off - this would indicate a possible loose connection, that is affected by the vibration, of the bonnet closing, slight as it may be - did it shut off when you activated the bonnet latch, or before that - Tex Terry, II - 1991 XJS V12 Classic Coupe, 1986 XJS V12 Coupe - msg sent 6/16/2020 2321hrs. EDT USA.

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Last six of vin is 640589 I believe the mfg date on the door is either 11/90 or 12/90. I will try replicating the bonnet closing tomorrow. I started the car with the bonnet open, idled for maybe 5 minutes and then shut the bonnet by dropping it 12 inches from the latch. Car shut off. Another time was when I was driving at about 35-45mph. Each time the car started right up immediately and continued driving.

This being my first xj40 I am unsure if I feel the hesitation while accelerating or if it is lack of power or it’s just so smooth I can’t feel anything. I have taken it up to 90mph, kick down function works. But something feels off about the power. It idles smoothly.

So you have an external fuel pump. The post about the seal/canister in-tank issue will not apply to your situation.

I’m sure you’re familiar with the online parts catalog, but if not:



Should have time to work on the xj40 this weekend. Here are links to YouTube containing he symptoms I’m having. Hopefully it is helpful in figuring out what’s wrong

Hello Steven - in the video of the brake unit shaking, have you checked to see if you have a broken, or loose fitting - Tex Terry, II - 1991 XJS V12 Classic Coupe, 1986 XJS V12 Coupe - sent 6/17/2020 1713hrs. EDT USA.

I think you will find the clicking noises you are hearing are just the various relays kicking into life when you energise the ignition.
When you first turn the ignition on after sitting overnight you should hear the pump for the brakes run for about 30 seconds and then stop. You should then, with the ignition off, get about 20-30 pumps of the brake pedal before the pedal goes hard. This will show if the nitrogen ball is holding a charge or if it is now defunct.

Your car should have an internal fuel pump. The pre-face lift XJ-S had a sump and external fuel pump. You may also want to change the fuel filter. I believe the majority of Jaguars I have purchased with up to 88,000 miles on them have had the original fuel filter, belts, hoses, plug wires etcetera.


Surely a VIN 640589 indicates a mid 1991 model year (i.e not build date or date of first registration)

That means Steven’s car has the in-tank fuel pump

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I will get under the car today to see if there’s an external fuel pump or not. Going to change the engine oil. Then do brake oil next week and then power steering etc

I checked around the area everything seems nice and snug

Hello Steven - glad it is secure - wonder why it was shaking so much - I have never seen one do that is why I mentioned it - maybe check the mounting bolts also, for the brake cylinder, in case they are loose - Tex Terry, II - 1991 XJS V12 Classic Coupe, 1986 XJS V12 Coupe - sent 6/18/2020 1045hrs. EDT USA.

Oops! my only excuse is the new JCP site …aaarghh!! :confused:

Didn’t see the fuel pump at all, did see the fuel filter though the thing is tiny!

Tried changing oil but don’t have a 30mm socket :open_mouth: will have to reattack at another date. Also dropped hood to close while running to see if the car would shut off but it did not.