This is my first post and if I make mistakes please forgive me. I have read posts until my eyeballs fell out and offer one help item and have some questions. All that follows is for a 2001 XKR convertible VIN# PA11xxx with approximately 90,000 miles. I have some mechanical abilities having owned, maintained, and raced 2 Austin Healeys, a Lotus 11, Elva MK6, Lotus 23, Brabham BT8, Lola T140, Merlyn FF, and a McLaren MK6B. I did all the mechanical– built engines, transaxles, etc etc. But this Jaguar is without a doubt the worst vehicle for maintenance I have ever seen. I am exasperated and discouraged.

First: replacing the brake switch. I am not as limber as some of you seem to be and had to remove the front driver seat. Found instructions and thought I would reiterate this for those who do not know. I moved the seatback as far forward as it would go, moved entire seat all the way forward, removed the two bolts at the rear of the track rails, and removed the long plastic cover at the side of the seat. Then moved the entire seat all the way backward, removed the 2 bolts at the track fronts, tipped the seat assembly backward, disconnected the TWO electrical plugs, and lifted the seat out of thecar.
I won’t bore you with all the efforts that didn’t work to get the new switch in.Finally gave up and resorted to the method prescribed by a gentleman which entailed drilling a small 1/16” hole about 3/16 to ¼ deep in the end of each mounting stud. I then took 2 pieces about 10 feet long of 14 gauge thw wire (with a 0.115inch insulation OD), fed them through the mounting holes from outside to inside the car, and labeled them FRONT and REAR for the hole position. This gave me enough wire length to comfortably work outside the car. I then stripped the insulation off the end for about ½ inch and used the JB WELD KwikWeld Steel Reinforced in the TUBES – not the 2 cylinder dispenser – to epoxy the copper stranded wire into the holes in the mounting stud ends. Using the tube product allowed me to mix the epoxy a little hotter by using a little more hardener than usual to facilitate quicker setup time. Be careful to not get the epoxy on the threads. I was surprised at how strong the bond was. I waited an hour then gently pulled the wires back through the holes and diddled the switch around to work it up into the approximate position. Another gentleman mentioned that if you got the switch hooked on the brake pedal it would stay there. When I worked the switch within about 1 inch of the hole positions the wires acted as guides and the switch studs slid right into position in the holes and the brake pedal hook held the switch there so I could get out of the car and slide the nuts down the wires and turn them on. THEN I cut the wires leaving about 6 feet of wire on each stud and slid a ¼ drive deep wall socket down the wire onto each nut. Then I took an 11 inch long pair of needle nose pliers (from Harbor Freight), moved the wire into one corner of the ¼ drive socket hole and shoved the needle nose pliers into the hole. They jammed solidly into the square socket drive hole without harming the wire in one corner of the hole. I then turned the pliers and solidly tightened the nut. This left the wire still attached to the stud and after removing the socket I coiled the wires into a small tie wrapped bundle and left them there. This allows me to easily replace the switch in the future if necessary by removing the brake switch mount bracket into the driver seat area,unbolt the old switch, bolt a new switch on the mount, and using the same wires easily install the new switch into position. Hope this helps ya’ll.

Second: regarding replacing the O2 sensors. This has me very discouraged. I have codes P0171, P0174, and P1646 showing. I understand that 171 and 174 are highly probable for vacuum leaks. With the age and mileage of the car I naively thought I would just replace all the O2 sensors and the spark plugs and then work on the 171/174 issues. I compiled 16 pages of info about the O2 sensors from this forum and got to work. I thought the two holes in the interior under the carpet were a piece of cake until I discovered that I have to remove the center console because the carpet is solidly secured by the console.Then I discovered that I can’t get to the upper sensors from above because my car has heat shields that are impossible to get out unless I remove the engine.Then I discovered that from underneath the car there is absolutely no way I can get my hand up in the area of the upper sensors unless I remove the exhaust pipes (which I fully expect to be solidly rusted on.) There is a clamp on the right side exhaust pipe 5 inches behind the flange which bolts to the catalytic convertor. It seems to very slightly drip the combustion water condensation product.Then I found the grey and black sensor plugs and sockets. They are buried behind and underneath a snakes nest of very solid wire looms and cables which are almost unmovable. I can’t get my hand on them to unfasten them.
Questions:
What is the purpose of the aforementioned exhaust clamp?
Am I the only one with heat shields covering up the upper sensors? Removing the left side water overflow tank will not allow access because of the heat shield above the sensor and below the tank. The right side heat shield also totally covers the sensor and eliminates access from the top. None of the heat shields are moveable or removable enough to reach the upper sensors even when unbolted.
How did the gentleman using the interior access holes align the socket wrench on the upper sensor from below without being able to reach it? Did he have to remove the center console to peel back the carpet or is there another way?
The heat shields cover the nuts fastening the catalytic convertor to the manifold so I can’t even get to them to drop the cat convertor down.
How in the he** do you remove and install the upper sensors? The factory manual (whichI thought would give exquisite detail) just says, “Remove the upper sensors.”
The only way I can see to get to the sensor electrical plugs is to remove the throttle body.Is there another or better way?

This is absolutely the worst maintenance vehicle I have ever had. My romance with my cat is fading fast and reminds me of a line in a song from a porno tape, “A heartache in disguise!”
Please Help!!

 

If I am correct the heatshield will come out but is difficult and fiddly to remove (especially if you have big hands, had to get the missus to remove the one from my XJR for me). I have a problem with the same O2 sensor in my XK8 at the moment (but no heatshield in the way). The sensor is corroded in and will not move - starting to round off instead, so is going to need heat but with those pipes around I am very wary of doing this (Tried plusgas etc with no effect).

The connectors for the sensors are a pain to get to but they have a little plastic catch holding them on to a rack. I used a small bent pick to press in this catch and it came off the rack pretty easily. This will give you a couple of inches of play to work with for seperating the 2 parts (be warned - they can be a pig to get apart, I ended up having to use needle nose pliers to grip them and get them to split but that may just be because I have large hands and they are relatively small). Once they are apart tie a bit of string to the connector for the O2 sensor so that when you pull it through to remove the sensor you will have something to pull the new ones connector back to position with otherwise it is very fiddly and lots of swearing will ensue (don't ask how I know).

These cars can be very awkward to work on but there is a certain sense of satisfaction when you finish and the replacement O2 sensors should last for years so no worries about replacing them again any time soon (remember to use anti sieze on the threads when you put the new ones in).

I found that I could pull back enough of the carpet (start in the footwell as close to the hole as you can and just pull the carpet downwards to get it past the facias then work along towards the centre console until it will not come out any further. That should give you enough space to work with) without removing the center console to locate the hole and feed through a socket extension bar but I could not get the sensor socket through the hole so had to get access from above the sensor as well. You will need to remove the coolant expansion tank to gain access this way but that is pretty straight forward.

Now if only I could figure out my electrical gremlins.

 

If I am correct the heatshield will come out but is difficult and fiddly to remove (especially if you have big hands, had to get the missus to remove the one from my XJR for me). I have a problem with the same O2 sensor in my XK8 at the moment (but no heatshield in the way). The sensor is corroded in and will not move - starting to round off instead, so is going to need heat but with those pipes around I am very wary of doing this (Tried plusgas etc with no effect).

The connectors for the sensors are a pain to get to but they have a little plastic catch holding them on to a rack. I used a small bent pick to press in this catch and it came off the rack pretty easily. This will give you a couple of inches of play to work with for seperating the 2 parts (be warned - they can be a pig to get apart, I ended up having to use needle nose pliers to grip them and get them to split but that may just be because I have large hands and they are relatively small). Once they are apart tie a bit of string to the connector for the O2 sensor so that when you pull it through to remove the sensor you will have something to pull the new ones connector back to position with otherwise it is very fiddly and lots of swearing will ensue (don't ask how I know).

These cars can be very awkward to work on but there is a certain sense of satisfaction when you finish and the replacement O2 sensors should last for years so no worries about replacing them again any time soon (remember to use anti sieze on the threads when you put the new ones in).

Now if only I could figure out my electrical gremlins.

 

See if this helps:

https://www.jaguarforums.com/forum/x...cement-115991/

 

Thanks tberry & RJ. At Harbor Freight I found a smallish vise-grip that is extended to 15 inches long. Also I bought a set of 3 eleven inch long reach Hose Grip Pliers that have semicircle ends which could act like prongs to grab objects like the electrical plugs. I have been thinking that perhaps I could tape a stick to an open end wrench so I could wiggle it up from underneath between the exhaust pipe and transmission and use the open end as a cradle in which to rest the socket extension bar sticking thru the hole from the inside and then guide the socket into position. My squeeze is out of town for a week or so and I'll have to wait for her to get back to manipulate the extension from the inside. Thanks again for the encouragement. It is greatly appreciated.

 

Glad to see you got the brake switch replaced. Attached is a link to a how to that I posted.

Link to Brake switch JagRepair.com - Jaguar Repair Information Resource

Now for the O2’s I replaced all 4 of my sensors and two top ones I accessed from the top and two on the bottom from the bottom.

 

Thank you Gus. I had seen your post about the brake switch and the 2 nuts holding it to the bracket. I tried to undo the upper nut enough but couldn't reach it with a wrench (not enough room for the wrench) and thought I might not be able to get the small plastic washer in the proper position. I tried the "finger feel for the hole method" but couldn't make that work and so reverted to the drill/wire method and figured how to leave the wires for future use.
I have a solid inflexible heat shield above the upper right side O2 sensor made of something like hard compressed asbestos or asbestos covered steel and can't get it out except by destroying it. I got so discouraged I just looked at the left side and didn't really investigate. I'll need to get the right side from the bottom and will check to verify getting to the left side from the top. Thank you for your help. Very little bit helps.

 

I question going directly to the O2's I would be looking for other things related to P0171 & 174

 

I already bought the O2 sensors so my ego says it will not let those #(&%#^* things get the best of me. Will wait until wife gets back from trip and then regroup and use zen and a Chinese dinner for a greater power to overcome these issues and align my chi with the grand O2 sensor universe. :-) In the meantime I'll figure something out. Then 171 & 174 better straighten up their act cause I'm coming after them!!

 

Just FYI, I also had the 171/174 codes. Replaced the part load breather hose and cured the problem.

The plastic/rubber hoses in these cars have begun to disintegrate due to age and heat. As Gus suggested, might look to the various vacuum hoses first. Easier fixes if that's the problem.

 

It seems the 171/174 codes could be a multitude of things. Mine ended up being leaking fuel injectors. New seals on the injectors and all seems to be good.

 

Thanks JAG#4 and JOHNS55. Everything helps. I neglected to mention in my original post having the TRAC NOT AVAILABLE AND ASC NOT AVAILABLE AND FAIL SAFE ENGINE MODE LIMP HOME thing happen several times on a very hot day. Did the stop and start thing and it would go about 50mph until I pushed the throttle down for more and then all the above messages would appear and go into limp mode. After several times of this it would only run in limp mode at about 12 mph. Spent the last 20 miles home going vveeerrryyy slowly. Interestingly it would go 12mph uphill and then I could coast downhill in neutral with the engine running to feed the tranny oil pump and often got up to 30 mph here in the Texas hill country.
Also neglected to mention that previously for several months sometimes, not always, when driving 60+mph about 20 minutes after starting the car the RESTRICTED mode light would come on and after a few minutes go out. Codes said 171 & 174 but since the message would go out I didn't bother doing anything. Figured I'd wait until it didn't go out and then cure the problem.
Finally P1111, P0171, P0174, P1121, P1646 showed up with the limp mode thing. After much research and considering the age and mileage of car I figured I would start by replacing the brake switch and O2 sensors then see what codes appear and go after them. I didn't realize how difficult replacing some components would be. So I will replace the O2 sensors somehow and then go after the suggestions in this thread looking particularly for things that happen with temperature variation. Thank you all.

 

Are you sure you do not have a battery problem?

 

Attached are the P codes for your car take a moment and look at the possible causes. I asked that you check the battery because these cars are sensitive to power fluctuations and may be the cause.

Link to Codes XK8 2001 http://jagrepair.com/images/AutoRepa..._2001_OBD2.pdf

 

Thank you Gus for the code info. I had already gotten to them because of other leads you gave in other threads. I am sure everyone appreciates as much as I do the invaluable help you give. Thank you.
The first thing I did was pull out the battery and load test it. It was marginal so I had replaced it with a new one from Autozone (Duralast) recommended by Consumer Reports. It didn't make any difference.
My wife will be back in a week or two so I am going to wait to do anything else until she returns and can provide the extra hands to push pull etc. In the meantime I'll dream up some way to get the O2's in when she gets here.

 

I assume you checked the link I sent in post#4 and found it of no use. I have not tried it yet myself but thought it looked pretty easy, but it may not work on some years/models.

 

Yes, I checked it out. I had found it during my early research and tried to peel back the carpet. That was my comment about having to remove the center console because the carpet was firmly held down enough so I couldn't get a straight shot thru the hole. I'm not sure but it look like the socket may not fit thru the hole which means the socket would have to be put on the extension in the engine compartment after the extension is poked thru the hole. Which brings me back to the problem of being able to get my hand in a place it won't go.
However, have decided to go join wife out of town for a week or so vacation (haven't had one in ten years) and let the Jag sit until I get back. Then I'll let everyone know how I solve this puzzle - there has to be a way. It seems that some other Jags don't have the same heat shields which restrict access like I do. To me that is strange. Ah well, will continue this when I return. Thanks for your assistance!

 

Have you changed your fuel filter or checked the fuel pressure?

 

I have not checked the fuel pressure but a year ago both fuel pumps went out and I had to have it towed to a private garage that specialized in Jags. It cost me $1000 to get both fuel pumps replaced. (My car has 2. Had a new fuel filter put in at the same time. At those rates I decided to see if I could do some of the mechanizing myself.) I did take out the relays and use a jumper in the relay sockets to check if I could hear each pump running. I did hear them then I jumped the relay leads and could hear each relay click. Did not do the swap relays trick yet. I need to do that and check the fuel pressure.
I'm going to go join the wife for a week or so vacation and get after this when I get back.
Thanks for the ideas Gus!!