My newly purchased 1986 XJ6

I haven’t been on this site in a few years since I sold my last Jaguar, a 90 XJS V12. I found this car just browsing about 6 weeks ago and I wasn’t really looking to buy, but I couldn’t pass on the price. The car was sitting for the last 10 years untouched in an unheated garage as you can see in the one photo. I did some routine maintenance on it, including a new battery and new Pirelli tires, the one’s on the car were original. I replaced the fuel pump, because the original one wasn’t working and the engine started. I took it for a ride and it rides and runs very nice, and put some fresh gas in it, only about 3 gallons per tank. The change over valve in the trunk wasn’t working, I had gas spewing out of the right tank. I’ve read it was coming from the left tank, because of the change over valve not working. I took that valve off and cleaned it and prodded it with a Phillips screwdriver and felt movement inside, hopefully I didn’t damage it. I hooked it up to 12 volts and heard it clicking like it should I guess. Hopefully it’s working, I haven’t driven the car since I did that. I know I should drain the tanks, but probably not until the spring, it’s getting cold here. The car has 25,551 original miles on it and I bought it from the original owner, the interior is very nice, looks great except for the veneer on the console was peeling. I replaced it with new veneer but I’ll probably redo it, it came out to dark, but it looks a lot better than it did. The body has surface rust on the rockers and wheel wells but I don’t think it’s rusted through and the paint is original with a lot of crazing. I want to leave it as original as possible, so I may just have the rockers re-painted. Sorry for the long post, and I’m sure I’ll have plenty of questions in the future, like where to buy the washers for the gas tank drain plugs and I think both fuel gauges are stuck at about 1/4 tank.



Welcome back to the forum, I think you will notice a few changes to the site since you were on here last.
Well done on the purchase of the car, SNG Barrett, Welsh, XK’s will be some of your go to guys for the bits and pieces you are going to need.

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Thanks Robin, I appreciate it and thanks for the information.

Looks great!
The tanks are easy to drain and the valve is simple and could have been stuck. There is a giant rubber plug, if it is „gas tight“ when you blow into the closed off side it is fine. If it doesn’t cure it it is likely to be the two return valves behind the rear wheels.
Seat looks amazing, good luck!

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Looks a fantastic buy. Draining the tanks is easy and probably a good idea!


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Thanks David for the good information, I might have to check those other 2 valves. The interior is really nice for it’s age.

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Thanks David, It was a great buy and I always liked the XJ6’s body style. I’ll drain the tanks in the spring, I probably won’t be driving the car in the winter months.


Actually, better to drain them now, and let them air out, over the winter months.

Failing that, filling them will help minimize any further condensation in them.


Welcome Joe,

what a nice find! If the sill rust is superficial and there is no windscreen rust it seems you’ve found that time capsule car everybody loves no matter whether or not the paint crazes.

It sounds amazing though that it started and ran well after like 10 years of sitting - this procedure might have killed an otherwise good engine, but it seems you got away with it. What I don’t quite understand: were those tanks empty so that you put in 3 gallons of fresh fuel and ran on these or were the tanks partly full and you only added fresh fuel? In the first case the tanks seem to have persisted well - obviously no flaking rust or other debris transported into the fuel pump. If that is true, I’d fill up the tanks. In the last case the original fuel seems to have persisted well because the three extra gallons wouldn’t make an XJ engine run on stale fuel.

As a precaution I’d start with peeking into the more or less empty tanks, and then go on filling only one tank to check tightness. Fuel odors would occur if the tank were leaking. Then continue with the other.

Good luck with this nice car


75 XJ6L 4.2 auto (UK spec)

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Good idea, I probably should do that. Thanks for the tip.

Thanks Jochen,
There is a little windscreen rust but only in a few small spots, but who knows how it looks under the rubber trim. I think the tanks had some gas because the gauges were at 1/4 of a tank but probably stuck there. Good advice about the tanks, so far I don’t smell any gas leaking but I haven’t filled them all the way either.

There are two causes of ‘cross-flowing’ tanks, Joe; the changeover valve fails to switch - or a failed return valve.

Do verify that the changeover and not a return valve…?

xj6 85 Sov Europe (UK/NZ)

You should replace those outboard headlights with 7" units. It’s what Sir William intended, undone by DOT regulations only permitting 7" units on 2-headlight systems, not four. But those rules have been repealed, cars have all sorts of combinations of headlights these days.

Looks very nice. I’d spend some time in the winter changing out all the fluids before driving it much though. Brake fluid especially as it tends to absorb moisture and deteriorates over a ten year period.
It’ll be good to see it come to life.

Thanks Kirbert, that’s good to know. I wasn’t even aware of that.

Thanks Andy, I know the brake fluid and coolant needs changing for sure. I may just have a shop do that, I hate bleeding brakes, and with the rear being inboard makes it even worse.

Thanks Frank, I will have to check the return valves too and see if they’re working.

I did the brakes in the driveway in under two hours and I am not a good mechanic.
The changeover valves look more or less like these:

few parts to break.
You can do the headlamps at a much later stage if at all, but for the return valves, let the engine run (maybe change the oil too after a few miles) and open the gas cap. Push the flap down and make sure that fuel is only returned to the selected tank respectively.

Thanks David for the photo of the changeover valve, I was curious how it looked internally. That’s good to hear about the brakes, I’m more of an average at best mechanic too. I did change the oil and filter before I started the engine. I’ll have to check the return valves to see if they’re working, hopefully gas won’t spew out when I open the gas cap. Are you saying to open the gas cap while the engine is running?

Yes; if you peek in there you will see a stream of fuel running back into the tank. As long as you don’t smoke there is no risk.


This is the view of the return pipe with the tank and gas cap removed.
If you feel somewhat confident about oil and filter you can do the brakes. I did it alone but a helper to push the pedal is useful :slightly_smiling_face: just make sure the car is supported well and keep the reservoir full.