How to Bullet proof z 1997 xk8 convertible
 

Hi all, I'm about to do the foolish thing and buy a 1997. 96k miles on the clock and "well maintained". Ive done my homework on Nikisil, secondary timing chain tensioner, convertible top hoses and pressure relieve valve/manual operation, water pump, t stat housing, sealed for life transmission...etc. what have I missed of major importance?
I can do most wrenching myself. This will be a daily driver but not my only transportation. I want a to make it a solid driver and dependable. Is it too much to expect? Thanks.

You can add plastic serpentine belt tensioner/fixed pulley to that list especially at that mileage. Proactively replacing (like I should have done but didn't) the 2 pulleys and belt will be good insurance against being stranded and possible engine or fan damage.


Dave

Thanks yes I do remember reading that one too. What is the verdict on the transmission? Can these be 200k mile trannys if cared for or should I expect a rebuild very soon? If rebuilding do the kits have upgraded components?

Hi.


Very interesting thread. From my personal experience and lots of reading I have the following comments:


Upper secondary tensioners. Failure and jumping a tooth may destroy your engine beyond economical repair.


Nikasil. An engine running well today will probably go on doing so.


Serpentine belt, tensioner and idler should be changed. My tensioner gave up at 65k miles.


Radiator upper and lower hoses blowing off will leave you stranded.


TPS (Throttle Position Sensor) have been giving lots of trouble in high mileage cars.


Fuel pump failure will stop you. Cheap but complicated to change. (Fuel tank removal)


Transmission ZF5HP24. Failure/breakdown of A-drum. Seems to originate from pressure spikes caused by tiny cracks in hydraulic valve body. My gearbox broke down after some spirited driving on German autobahns.


Thermostat housing. Change to high quality aluminium.


Heater hoses in engine "valley".


ABS warning caused by dry soldering in control module. Easy fix.


A weak battery will give you all kind of electrical gremlins. First sign is trouble with window drop.


I can now see I made a long list.
DON'T BE SCARED
Most problems are easily fixed if you can handle a wrench. But the -97 is 18 years old, and it is a complicated piece of machinery.
It is also a kind of transportation that will give you lots of pleasure and a large grin on your face.:D:D:D:D:D

Oddly none mentioned this yet, Parts of your front / back suspension will need replaced depending on what the PO has done as far as service in this area. All the rubber will have aged. Just so you know in advance you will have to drop some $ in this area. Good Luck with your ride

This is great thanks. This doesn't scare me off. So for the tranny valve body is it changeable without dropping the tranny? Will a new valve body have the same issues or have they been improved?
Any early tell tail signs a tranny with this issue is on its way out?
TPS yes I forgot to list it. I see a rebuilt isnt too outrageous.

Will the new serpentine belt tensioner have a greater expected lifespan?

Thanks jamdmyers, you talking about bushings or other things too?

Shock mounts unless replaced with probably be bad. Check the ride height from the top of the wheel well arch to he center of the hub it sb 15.5" if lower things are going on (.5" maybe just old springs and not a worry)

valve body can be changed without dropping entire tranny. The other issue that can occur with the tranny is the A-Drum failure but tranny can be rebuilt.


check the foam in the Upper shock mounts for front for signs of deterioration - visible by drop in front and foam chunks breaking off on the mounting area. If bad enough, you will get front end noise as you drive.

No, the OEM replacement pulley and spring pulley are also plastic. I found a cheaper all metal replacement for both pulleys and posted it here:

Metal pulleys in sticky thread.


Dave

DaveInVa I did read that too. Good to know the upgrade will last longer.

I cant seem to find anything on valve lash interval. Anyone know?

Hi again.


I agree that all the suspension rubber bushes will have to be changed eventually. Forgot that as mine had been changed by previous owner. Same goes for front upper spring mounting. But these problems will not leave you stranded. They will show up gradually.


I think the transmission valve body can be changed without removing the transmission from the car as mentioned in another post. Never tried, so a kind of unsure. If you google ZF5HP24 you will find lots of information. These boxes are also used by Range Rover, Porsche, Audi and VW.
It is fairly easy to change the transmission oil and filter despite roumers of the opposite. Essential to use the correct oil. Jaguar is expensive, so I bought from VW.


Now to the top hoses. Earlier cars have different hoses than later. The changeover might have been in 98, but I cannot confirm this. I have the earlier ones and haven't touched them except installing the excellent remote top modification. They are marked as you can see from attachments. (Pump in background) Knock wood, no leaks so far.

With such numerous issues one wonders if the problem is design or quality control. What has allowed Oysters to hold up where others have failed?

It's hard to predict what will happen ten years later. The English cars report far fewer hose failures, less sun? The top latch piston seal may still fail, as well as the ram seals.

Many of us have changed the transmission pressure valve to the newer model as per ZF recommendation. They claim it will prevent pressure spikes as long as the valve body is not worn. And yes, it's easily done without removing the transmission.

http://jagrepair.com/images/AutoRepa...%20ZF5HP24.pdf

I'm sure that is a factor but also UK owners tend to use their Jaguars as daily drivers and regularly used XK8/XKR appear to have less issues all round than weekend or fair weather use only vehicles.

Graham

Thanks RJ237, so in looking at the TSB I wonder if the valve body wear is due in part from the original sealed for life idea? Contaminated fluid being forced through a marginal pressure valve. In any event one more for the fix it list.

Thanks Graham, looking at the number of posts and thanks you have I've got to believe you and that is a good thing for me. When I get my hands on mine I don't think I will want to put it down. Although I wouldn't put it past Jaguar keeping all the good ones for the locals.

5HP24 Valve body rebuild

Found this write up regarding the pressure valve upgrade. Nice pics and other info. Not sure how identical the rest of the info relates to the jags 5hp24.

Annual MOT in the UK, and maybe the equivalent in Norway forces
at least a bare minimum of maintenance.

The difference in fuel cost probably pushes the ownership demographic
into a different category.

Hi again.


In a forum like this you will get a lot of negative comments. This is obvious, as most members post when they have some problems. You have to be realistic. We have complicated cars being 10 to 19 years old. You will need time and patience to keep them running. They have a build quality equal to or better than comparable brands. (Take a look at other car forums, and you will see real problems.)


We paid a fraction of the original price, but the parts are just as expensive as when the car was new. You will have to do most of the maintenance yourself. If not, you may as well buy a newer model considering todays workshop prices. You will need JTIS, JEPC and hopefully a code reader able to read Jaguar specific codes.


The electronics are nineties design. You can not compare it to todays standards. But it is very advanced. Think of it this way. You have excellent performance both in the -8 and even better in the -R and at the same time reasonable fuel consumption. The Jaguar V8 is a masterpiece of British engineering. The performance figures beat most of the comparable engines in its class.


Now for the design.
This is a matter of like and dislike. I think it is by far the best looking car I have ever seen, Both the coupe and the convertible are design gems made by the late Geoff Lawson. It is at par with the E-type. Having been in aviation all most of my life, I think it is the same class as the Supermarine Spitfire and the Hawker Hunter. It has a timeless look that will stand out from the crowd. That is not what you can say about todays models.


HAPPY MOTORING