Last week I bought a 1993 XJ40 with 69k miles. Picture perfect from the outside. Beautiful flawless wood inside.
I have a rough commute that requires about an hour of idling every day.
The first time I tried it the low oil pressure light came on and the gauge was down to nearly zero.
I started a thread about this.
Today I found out that the reading is correct and at low rpms the car is getting insufficient oil pressure.
It also ran hot while idling and climbing hills. Came to find out today that there is water in the oil.
So now I´m trying to find out if ONLY a head gasket job will solve the cars ills or if there are damaged lower end bearings also.
And just for fun some weird electrical stuff popped up. The trunk is locked and will not open no matter what anybody can think of to try to open it.
The last time I used it I opened the trunk to see if I could get a look at the electric antenna which stopped working and seemed to have become disconnected because there are no radio stations coming in.
All in all it looks like I threw away a few thousand dollars on a really pretty car that won´t be leaving the repair shop anytime in the near future.
Any suggestions?

 

Boy.
Rough one.

289 Ford?

If anti-freeze went through the bearings, it generally makes them toast.
If you changed the oil to a 20/50, and until it became waterlogged the oil pressure was good, maybe you're okay.
If new oil didn't help, then a head gasket certainly won't.

Theoretically, if water has been present for some time, there can be corrosion on the oil bypass valve that can casue problems.

I know on the sixes, or at least on mine, it's external access.

Dave

 

Can I put in a motor from a series III? I can find that more easily. The transmission is different. Is it possible?

 

Don't know.
Emission inspection requirements may come into play.
I've seen some strange stuff over the years.
Oil gallery core plugs popping out.......especially Chrysler V-8's....loss of oil pressure.....but have no idea on that one.

Let me ask someone who knows (if I remember when I see him next) about bypass/relief valving.

 

Thanks. I don´t understand the thing about the relief valving.
I just did the smog a week ago so there are two years before I have to worry about that.

Feedback is much appreciated.

2002 S type 4.0
1993 XJ40 Sovereign
1993 XJ40 (needs help)
1992 XJ40 Sovereign
1985 XJ6 Series III
2004 Lincoln LS

 

Okay, did a little research.
On the AJ6 engine in an XJ-40 there is an oil pressure relief valve access plug in the bottom front corner of the sump (oil pan).
LF corner, straight in from the bottom. The main drain plug is in the rear of the pan.

Have your shop pull the plug (probably most of the oil will come out), insert a deep socket to fit the Oil Relief Valve Plug, remove the plug and watch for parts.
There is a shaft (called a "Support Mandrel") surrounded by a Oil Relief Valve Spring.
At the very top is the Oil Relief Valve Plunger.
You may need a stiff wire with a hook in the end to get it out.

It needs to move smoothly.

Check it for burrs, garbage, corrosion.
Either clean it (and the bore) or replace it.
Make sure the spring is not collapsed or broken.
Personally, I would use a can of Brakleen with the wand and spray up into the oil pump bore to flush out any junk.

Inspect the bore and seat when it quits dripping with a strong light.

Lube the parts and re-assemble.
Hopefully you will find the issue.

There MUST have been a reason they put the external access plug in there......like maybe this happens often?

I have a soft, skinny bottle brush for cleaning and not scratching.

Breakdown here, look on page 28:

http://www.xks.com/jaguar/catalog/pd...15_113_146.pdf

There are o-rings on the pipes to the pump.
One side looks like pickup, the other pressure.
Conceivably the o-ring on the pressure side has failed, which will require pan removal.

 

Sorry to hear about your troubles on your lovely ride . I hope you would have had a master key that opens your all locks . I had a similar problem w/ my ride too .
Press VCM button and see if any FUSE I or Fuse not what is being thrown on your screen .
Other than that those engines are very durable and powerful too . As for the oil , we switched to Castrol 10 W 60 and so far so good .

 

Thanks for the feedback and help Curmudgeon and Cadillac.
I´m leaving town for a couple of days and will talk to the mechanic about the relief valve when I get back.
Also will try the VCM button. The trunk will not open with the key either. When using the remote I can hear the solenoid click, but the latch remains in the locked position.
I´m thinking of writing this one off and maybe saving it for parts. But the body and interior wood is in such outstanding condition it would be a real shame. And in normal driving conditions it ran fine. But I can´t use it for my commute and that makes it basically worthless to me.
I don´t know.
I think a motor swap might be the best idea, but I just don´t know what´s involved with that on an XJ40. Anybody have experience with that?
I don´t have confidence in the engine at this point.

 

I think one of your fuses gone ....Give me a few minutes so that I can get my owners manual to troubleshot your problem as far as I can .
From what I see , you first need to bring your trunk set to manually open position ,it seems it can open by remote key fob by default .

 

Here you're off the page 42
Manualy Only Operation :
To lock:
Insert the key in the vertical position , turn 90 degree clockwise and remove.With the lock in this position it can't be operated electrically .

To unlock :
Insert the key in the horizontal position and turn 180 degree anti clockwise.Return the key to vertical position to remove .With this lock in this position it can be operated electirically .

Normal Operation ( w/o overwriting the remote function )

To unlock when the doors are locked :

Insert the key in the vertical position and turn 90 degree anti clockwise.Return the key to vertical position and remove .The luggage compartment will remain unlocked and must be either locked electrically by operating a front door lock or manually with the key

Hope those helps

 

Thanks, Cadillac. I´´ll give it a try.
Regarding the motor, I´m hoping the low oil pressure at hot temps and low revs is a result of having water in the oil and that replacing the head gasket will solve the engine problem. We´ll have to see.
Appreciate the help.

 

No problem , anytime panza and please keep up updated on your issues

 

Well I think I have some good news. With the oil additive the oil pressure increased quite a bit at all temperatures. So it looks like we can go ahead with a head gasket job and the problems with the engine should be solved. I understand that replacing the head bolts at the same time is recommended so I will do that also. No point in skimping when there is so much labor involved.

Regarding the trunk, I think you led me to the answer Cadillac. I tried the key, inserting it horizontally as instructed but still nothing.
I decided to look in my owner´s manual, which was laid out a bit differently. It made mention of a trunk latch disable feature. Basically designed so valets cannot open the trunk no matter what. In order to do this a 90 degree turn of the key to a certain direction will lock the trunk and make it so that the trunk can not be unlocked by unlocking the doors, using the remote, or using the switch in the glove box.
Then there was a note... The green headed key if used after enabling the trunk latch disable feature still will not open the trunk. And OF COURSE, that´s the key that I gave the mechanic. So it seems that if I swing by the repair shop with the master key that the trunk should open and the mystery will be solved. We´ll see, but I´m confident that´s what´s going on here. Just another little bit of Jaguarism that I was unaware of. Next time I´ll tell the mechanic not to lock the trunk by using the key.
Thanks for the suggestion and I think you helped me to find the answer!


Panza
too many to mention due to becomming an obsessive Jaguar owner

 

Thanks for your replies panza
I had a similar problem w/ my trunk "refusing" to open too . Master key for sure should cure your problem .
Once you open your trunk using the master key then follow the instructions that begins with Normal Operation ,this is what I did and so far so good

 

I picked up the car from the repair shop temporarily. It was taking up space there and the owner and I were afraid it would get scratched. It drives fine for normal use but that won´t suit my needs because I need a car that can idle for one to two hours in traffic without problems.
I just got back the other car with the fuel pump problem and need a week before I can spend $325 for oe head set and head bolts. By the way, the xj40 with the bad fuel pump started having a fuse problem for the rear tail lamps. It went away by just switching the fuse with another 10A fuse, even though it wasn´t blown. I heard that sometimes on these cars you need to re-seat or replace the fuses.
Anyway, I inserted the master key and the trunk works fine. I re-read the threads and Cadillac had mentioned right from the start to use the master key, but it didn´t register in my mind. Thanks again to all for the feedback.
I´ll let you know how it goes when the new head gasket job is done. Meanwhile I have way too many cars and if somebody in SO Cal wants an XJ40 at a good price I´m listening. Thanks
Panza
2002 S type 4.0
1993 XJ40 red
1993 XJ40 white (waiting for head gasket job)
1992 XJ40 Sovereign green
1985 XJ6 white
2004 Lincoln LS

 

Thanks panza, at least you could be able to open the trunk .
All my best wishes for you as well as best of luck for the rest of your jobs