My '98 XK8 Coupe has a little over 40k. It has never had any engine or transmission work done on it for the 17 years of its life. After I bought it, I took it to the local Jaguar dealer and had the oil changed, radiator flushed, brake system purged and had the car generally gone through...they found nothing. (@$800.)
After researching the potential issues with this car, I've decided to pro-actively have the tensioner upgrade, water pump upgrade and thermostat assembly upgrade. An expensive deal (@3k).
Now, I'm researching the transmission issues...tranny currently runs fine. However, the transmission, according to all the info available to me, has never been serviced in the past 17 years. It's also an expensive undertaking, changing the fluids in this ZF tranny...@$750. Should I or shouldn't I bite the bullet and service he transmission? Is there an interim step?...can you check the color and aroma of the fluid to tell if it's ok?

 

You have already answered your own question. At this point it is a case of age vs. mileage. Changing all fluids is a very good approach.

Keep in mind all the rubber and plastic under the hood is 17 years old as well. Hopefully the dealer checked that while they were in there.

Lastly, better find yourself a good independent mechanic. As you are learning, the dealership will be the most expensive option and not necessarily any better at the service. For example a good indie would probably charged half what you paid for the tensioners and upgrades.

Better still, go the DIY route where possible. Plenty of help and support on this site.

 

^^ Spot-on advice given above....

Study this forum and learn to DIY as much as you can. There are many very knowledgeable and helpful folks here who will assist you whenever possible. This forum is by far the most valuable tool in your toolbox....

 

Thanks...I have, in fact, found an independent mechanic in Flemington, NJ...I'm taking the car to him tomorrow for the tensioner upgrade et al. I don't however, at this point of time, feel comfortable DIY with this car.
I've certainly considered issues re: seals and gaskets, but they don't at this point seem to pose catastrophic issues, whereas it seemed to make sense pre-empting the tensioner, pump and thermostat issues before the engine ate those sub-standard parts.
I'm still undecided about doing the tranny service....I guess I'll discuss it with my new mechanic tomorrow.

 

The transmission A drum is a problem with the XK. In order to extend the life of the transmission I would recommend the solenoid and valve body upgrade along with the fluid and filter change.
Lost my trans at 97,000, A drum failure.

Search the forum and look at threads concerning changing out the shift solenoids and the valve body to stop the pressure surges from damaging the A drum.

 

A great many of the DIY crowd have used alternate transmission fluids such as Castrol Transmax Import Multi-vehicle at a fraction of the cost of OEM. Doing multiple drain and replace versus power flush is probably lower risk.

When the transmission pan is off to change the filter is a good time to change the main pressure valve to the ZF upgraded version. Link below.

http://www.jagrepair.com/images/Auto...%20ZF5HP24.pdf

 

I'm all in on preventive maintenance, I'd much rather perform winter overhauls and not worry about some breakdown during the summer driving months. While your car has low miles as said above it's age that is the killer of fluids and rubber. I'll pick several items and work them out over the winter. Kinda of a rabbit hole in some ways, once I start I then go 'oh might as well change this while I'm here' kind of thing, but I love this car and with time and care it will serve me for some time to come.

Good luck with the indie good move against a Jag dealer, but certainly come back to the forums and ask any questions about what he's charging, doing or wants to do, these guys here have all been down the road on almost every repair on this car.

 

https://www.jaguarforums.com/forum/x...ng-kit-146100/

 

FYI, Your 98 does not have a ZF "Sealed for Life" Transmission. Changes are expensive on ZF 6 speed, and they do manifest problems when the friction modifier dies of old age. $750 for a fluid change on a 98 sounds out of line to me.

 

His car does most certainly have what was called a ZF 5HP24 sealed for life transmission. As we now know that was pure advertising nonsense.

 

Thanks for all the input...I did in fact have the tensioner service done, the water pump and thermostat assembly upgraded. I also had the transmission serviced with new fluid and filter. The mechanic also replaced several hoses and a couple of seals. The tranny service only ran about $400. (only?) but my 1st visit to my new Indie was in excess of $4K.
There seems to be a "school of thought' on this forum that increased replacement of critical fluids; motor oil, transmission fluid, coolant and brake fluid (more often than Jaguar suggests) might be the key to increasing XK8 longevity.
Although it's not my daily driver, I have driven the car over 1k miles is the past month or so...it's a great automobile.

 

Steve,

The first thing I do with a new (to me) vehicle is to change all the fluids.

Regardless of what the maintenance record shows, you can never be absolutely sure everything has been done previously to schedule and this gives me a known starting point for future maintenance. It may not necessarily result in increased longevity but it certainly does increase reliability. However, I don't believe in making more regular changes than the Jaguar schedules.

On the subject of transmission fluid which is NOT a Jaguar scheduled change, I see you followed the recommendations and have had this done. Across the tech forums there is sufficient evidence to indicate this does increase transmission life and is a worthwhile expenditure.

I hope you continue to enjoy trouble-free driving with your XK8 Coupe after all the work has now been completed.

Graham

 

You can do the water pump and tstat work. It is EASY. Since you will have the Tstat off you can get to the WP much easier. Unless you are keeping the car LONG term putting OEM stuff back on is fine I think. The early year WP (plastic impeller blades) issues have been fixed with updated units.
Frankly if you can do an oil change you can do this repair. The WP is one of the easiest I have ever encountered to replace.
As said here DO NOT go to a dealer with work to be done to your car when ever possible.

 

Graham...Thanks for your input. I also believe in replacing all critical fluids in newly acquired vehicles. Unfortunately, I went to a Jaguar dealership for the service and paid a lot of $$ for changing oil, coolant and brake fluid. I guess, that was a learning experience. I would add that longevity and reliability, in this case are synonymous...in that you can't really have one without the other.
I also wanted to mention another thread in the forum relating to ZF fluid replacement recommendations. If I remember correctly, there is, in one of our forums, a copy of a letter from ZF modifying their "sealed for life" policy to a specific mileage/age. However, up to the date of that letter, it was their policy/recommendation that all ZF 5 speed automatics were "sealed for life".

 

My first car was a 1973 Triumph GT6 MK3. Beautiful pile of crap; I think mine was built by scabs(1/73) and owned by morons who abused it before it got to me. I owned it from 2004-2006. Weird thing is I sometimes miss it.

If you can work on your Bugeye and GT6+, these Jaguars are well within your abilities. There are some complications added by electronics and such, but a good methodical person with a set of the right tools can handle this stuff super easy.

"sealed for life" is a fallacy since I guarantee the owner of the car doesn't have the same view of "life" as the manufacturer.

I'd go full on and replace any fluid in the car. I'd recommend the T-stat, T-Stat housing, WP, Tensioners, do the shift kit mentioned on the ZF box, all cooling hoses, and any easy to get to vacuum hoses. All of that will help ensure trouble free motoring.

There are tons of opinions on what fluids and filters are best, but the most important thing is just changing them regularly. I'd rather have a car maintained on the dot with Walmart fluids and filters than a car sporadically maintained with Mobil1/RoyalPurple/Redline/etc. I'm very partial to going the more expensive higher quality route and then changing prematurely for peace of mind.

 

I noticed the later model 6 speed trans owners have found the Ford LV trans fluid works just fine replacing the outrageously expensive OEM fluid. Has an alternative fluid been found for the five speed?
Regards,