Hello everyone.
I recently acquired a 92 Sovereign 4.0 which was sitting for a while. 211,000 km on her.
I occasionally ran her in the underground garage for short periods, but last week and today she began blowing out quite a lot of blue smoke.
i just replaced the flat battery and started her for tests.
the blue smoke was a lot on start up but tapered off a bit as she warmed up.
oil is a bit high.
I’ve heard that the 4.0 has some valve stem issues.
any advice on where to start?
my neighbours aren’t happy with the smoke show in the underground garage….

 

After sitting the XJ40's do smoke a lot on startup as worn valve seals allow the oil up in the cam area to make it's way into the cylinders. They all do this, and renewing the seals is often only a temporary fix as the replacements don't last too long before they do the same thing. Fortunately the smoking is a whole lot less and may disappear altogether if you drive the car fairly often and have the oil at the correct level.

I never worry about or even notice it and my car has 280,000k's on it.

 

it’s kinda frustrating because she wasn’t doing it before, and I haven’t put her on the road yet so I can’t drive her far.
I took her outside last night and parked her idling in the parking lot to run the oil out or the smoke would stop. The smoke slowed down a bit after 5 m.
should I run her out more?
I’ll check the fluids again to see if any issues.
the coolant tank cap is quite tight, I’m worried if I push it anymore it’ll crack the plastic tank. (I’ve done that before in another vintage car).
there are no leaks per se.
also, does the “lightning” symbol denote the alternator not charging?

 

Some owners, if planning a long period of storage, will pour some oil into the cylinders - perhaps that's been done? Whatever the cause, valve seals or other reason, fact is you are burning off some oil either in the engine/exhaust or possibly sucking it in through the intake - the large corrugated hose at the throttle body can get loaded up with oil if not cleaned out now and again.
It may be that the oil used at the last oil change was too thin or synthetic, recommended viscosity for this engine is 20/50 and personally I use GTX, not synthetic.
Coolant cap is often very tight. You should be able to remove it though ...
As far as the lightning bolt goes, that symbol does sound like an electrical issue, not had that one myself so just guessing but you should check yourself with the Haynes manual. You can download that online, do a search for Haynes in the archive for a link to that.

 

I’ll take a look at the intake to see if there’s any oil there.
thank you.
I’ll try to run her up and idle her for longer than 10 minutes to blow off the oil.
I think the steering rack is having some issues as there is a “groan” on turns, and the steering wheel telescoping lock lever is missing beneath the dash.
of the fun.
I’ll run the set diagnostic on her later on.
I think both our XJs have the same colour scheme of metallic blue with beige interior.

 

That was the colour scheme of my parts car that I dismantled back in 2016 ...long gone!

My DD is Oyster metallic with doeskin interior

 

I started her up. Oil pressure was reading at 5-6 on the gauge. Smoking but then she stabilized and was only biting off a bit. Checked the oil dipstick and all was good.
then the oil pressure started dropping off to the redline and then the oil burning started again with a vengeance. Shut her down but will try again.
also I opened the boot and could smell some fuel as I have in the cabin at times.
Electrics wise, the fault locator tells me “fuse 1” and when I open the door, the fans kick on if the switch is activated and stop when I close the door. Is that unusual

 

Which fans? Heater or engine? fan switch on climate control? Whatever fans you're talking about, opening and closing door should have nothing to do with them! You may have fusebox issues, cold and cracked joints on rear of fuse box is a common problem on these cars.

Not sure about the oil issue ...seems odd to re-occur like that. Oil pressure sensor also not reliable, known failure component, however if oil is getting into the combustion chamber it must be coming from somewhere. You could do a compression test and see how even cylinder numbers are, might be a clue as to what's going on - also - have you examined the plugs? do they look all the same and just how do they look? Any oiled up?

 

itīs typical for the aj6 engine to smoke on startup, but itīs not typical that it will come back after the engine is running for some time. That sounds like a different issue.