Hey Guys--
I'm thinking about buying a 2004 XJ8 with about 100,000 miles from a guy who lives locally in North Carolina. I drove the car yesterday and rides and handles well. The transmission was replaced by the local Jag Dealer last year. All air suspension parts are original.

Questions:
I am worried about the longevity of the air suspension, can I easily test for leaks in the air suspension? The car looks like was sitting normally when I drove it and no faults were lit.

What are other common faults around 100,000k that I can test before I buy?

What do you wish you knew before your bought your used X350?

 

Hi Zuma

The most common failure on the air suspension is the compressor mounted LH side behind the front bumper. This eventually fails to pump enough air in the time allowed so posts up fault messages, (and a code is stored in reference). These things are not, (IMHO), all that expensive if you buy a service exchange item, being about £300 here in the UK with a fitment time for an experienced Jag mechanic of about 30 minutes. Air spring units can fail and can be expensive, but in the US there are alternatives by Arnott Industries at less cost.

At your miles, I would have expected the compressor to have already been replaced. If it is standing correctly and a test drive shows no faults it should be OK.

More mundane things on the suspension seem to fail earlier than us poor owners would like, namely:

- Rear lower wishbone bushes
- rear roll-bar link bushes
- Air spring lower bushes (front or rear) cheap to buy rather expensive to replace due to labour time

However, again, at your miles I would expect some replacements to have been done already.

Minor corrosion at the leading edge of the trunk lid and possibly at the bottom of the rear screen can make it look unslightly - if this is present you need to negotiate a lower price. Of of course this does not affect the performance of the car at all. At your miles, if this was going to occur, it would have occurred long before this mileage, but check all the same.

 

If you did not hear any clunking noises from the suspension, they were most likely replaced. You did mention it had the original shocks?
Check for air leaks at the top mounts; have the engine off and listen for any hissing sounds. If the suspension stays up overnight, it should be ok. Check the engine compartment for signs of oil leaks, If there are signs of old leaks (no wet areas) it should be ok. If the engine compartment is a little too clean-check it after a long drive. Check the brake fluid, should be clear ( with a tint of color). Open the Cabin Air Filter Cover and check the filter. Look through the grill and check the fins of the condenser, should be able to see though it. Check the rotors and brake pads for wear. Check the tires for wear. If they are worn, check the wear pattern; inner tread worn more? Outer tread worn more? Center of tread worn? Both outer edges worn? Operate all electrical components to ensure they work. Check all body panels for fitment, do they "line-up"? What info may the Carfax be hiding?

 

Thanks for your input. Based on what I've read for an XJ8 with this age and mileage, I find it rather unbelievable that nothing has been changed on the air suspension system. I am going back to look at the car next week to investigate a bit more about the air suspension: So far I should:
1. Check for leaks by listening for a hissing sound after turning the engine off.
2. Check all tires for even wear.

Currently the car is not displaying any faults, no noises while driving, etc.

Reyesl, I will check the other items you mentioned engine oil, brake fluid, air filter, condenser

-----Couple More Questions:

Is there a way to bring up old fault codes that have been cleared?

Is there a way to test the compressor by raising and lowering the height of the car (like on the Audi A8 and Mercedes S Class)?

 

Be careful, because part of the air cycle involves blowing air back from the storage tank through the compressor to clear out the water trap. From my own experience, it seems to do this after a run when the engine is shut down.
Fronts seem to wear on the inside of the tread; they did on mine, anyway.

Once the fault codes have been purged, they cannot be recovered, and there is no manual control on the air system to raise or lower the car.

As Reyesl says do the normal routine checks on brakes, oil, etc. If possible, take a test ride of reasonable length, incl highway speeds if you can. Also check to see what service records are with the car. Are there any available on-line, and finally, make sure you get the Driver Handbook and other books telling you how everything works.

 

May I impart a few suggestions:
1. throw the car on a lift and carefully study the entire underside-look at suspension joints, park brake cable routing, disc wear, leak evidence, etc. Compare the outer shape of the trans pan and fasteners found with an OEM unit(s) to determine pan change (and hence fluid change) if no data is available.
2. drive the machine at 50-70 mph over some moguls to evaluate the shock (vs. air) aspect of the front airsprings. You can have good air but BAD shock on a single unit(s).
3. inspect the headliner especially at rear corners for sag.
4. check functionality of both key fobs.
5. cruise the machine at 30-35 mph in top gear, and observe tach, checking for slow up and down modulating which indicates trans fishing and the need for a reflash, and rolling stop trans "slip and grab" tendencies.
6. attempt to assess the headlights for intermittent flashing which would hint at a failing ballast etc.
7. it's hard to check during an inspection such as this but, the "hood open" sensor is sometimes bad or failing (won't allow you to key fob lock the car).
8. the t-stat housing can leak coolant slowly
9. there's been a great deal of input on oil color within this Forum, but, mine is always beautiful amber in color and still tastes ok 3,500 miles after an oil change.
10. check the functionality of all aspects of the front seat electrics and the rear window screen.
11. and the basics: battery age, coolant strength, tires, high speed vibrations, prior service records, prior owner info (young vs. old, male vs. female, shop vs. shade tree, etc.)
12. and after you've returned from a good test drive, get out and listen and smell what's going on under the hood. Coolant leaks can be detected by smell. Be sure and drive it in reverse some too ( and check the park brake).

 

I just dropped 300+ on a Jag dealer inspection of a Super 8 (as you may have noticed my whining in another thread) and was semi-impressed by their thoroughness, UNimpressed by the value/$$. 1 thing keeps on this prospect and that's that they said they would sell this one on their lot with a couple corrections which leads me to believe it's a clean car(won't see it before I buy).

Find a local Jag specialist and spend a bit on an complete going over.