Just got my 03 STR with about 40k miles from my dad.

He put new Goodyears on it about 400 miles ago, so I don't think that is the problem, but my coworker says that goodyears aren't the greatest.

That being said, when driving around town and on the highway, the car seems to be a little too stiff, like every little bump cause the car to bounce a little. It's not bouncy like a car that has no shocks at all, but a stiff bounce after every little street imperfection. It's hard to explain.

For a sport's sedan, I know the suspension won't ride like a cloud, but I don't remember it feeling like this when they bought the car new. I know this car has the CATS suspension so I'm wondering if that has anything to do with it, but I'm not getting any dash lights coming on either.

Tire pressure is set to the recommended settings as well.

Thanks in advance!

 

Sounds like your cats are not working , and if the whole car is stiff then it's not likely to be one shock playing up it will be a fuse or the modual in the boot/trunk , as thay default to rock solid with out the modual pluged in !
check your boot/trunk for water . As the modual is right at the rear of the wheel well on the left , practically as low as you can mount it .

 

Thanks for the response. I checked the fuse for the adaptive control just now and it's fine.

I can't see any damage to the module. Would a vehicle hard reset help? Or maybe unplugging the module and reconnecting it? I don't want to do anything to mess up the electronics. So if that won't harm anything I guess I can try that.

 

I'd check the exelerometers on the front and rear wishbones for damage or dislodgement
Also the plugs on all four shocks are clean , dry , and connected!
Also you can check the ohms of the shocks internal circuit with a multi meter.

 

The shock connectors look fine. I haven't found the accelerometers yet. Is there a diagram that shows their locations? And if it was one of these things, why wouldn't any codes be coming up?

For some reason I feel like the module is the culprit, but I don't know how to confirm that on my own.

 

You need to get under the car and look.

Is there any oil or dirt on the outside of the struts? Common for them to leak on the early STR. Are the wires hooked up and is there any damage to the wires leading to the struts?

Also by this time your entire suspension will have all the rubber boots split and broken. So after your inspection you should have an idea what you need to replace.

For sure you will need all the sway bar end links, The front outer tie rods, The rear toe rods and the top front control arms. If you are lucky the lower arms are still good. They are harder to repair by replacing the bushings only. If you have to purchase the complete arm (This is what Jaguar will tell you) it will be a LOT more expensive.

After you inspect post back what you find.

Be aware that you may have codes and they will be "C" codes that a normal cheap scanner might not be able to read. C is for chassis.
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Thank you so much for the advice. We had the car on my father's lift for a short period of time but I didn't have enough time to inspect everything and unfortunately they live a few hours away. I did notice some of the boots being damaged on the rear suspension as you said.

I will get it up on jack stands within the next couple of weeks to do a thorough inspection.

One thing I did notice while I was in the trunk is that there was a 2 wire plug near the back right corner unplugged, and it seems to be the trunk lid sensor, since when I plugged it back in, the boot open warning would stay on no matter what. I guess the last jag tech just disconnected it.

I'll post back with updates!

 

Any logged "C" codes related to a CATS system fault should activate a "CATS SYSTEM FAULT" warning on you dashboard information screen.

 

Good point but at this time I want to see the code output. The CATS light is triggered by many things so it's just a place to start.

Can you post a picture of the plug in the trunk? There is a white unconnected plug in the battery area and it's used only for shipping the car from the factory to the dealer. Make sure it is not grounded. But I am not clear if this is what you are talking about or not?

Please post back if you find any oil or grime on the struts. It is common to get a fine oily film on them after all these years but you don't want to see any drips.
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Here is the connector I found. I don't think it should be connected because the boot open warning works normally.

https://i.imgur.com/wKSg67S.jpg?1

I got under the rear of the car and took some photos. Definitely need to replace some bushings and suspension components. I'll try to lift the front up tomorrow and check that too.

https://i.imgur.com/TVe7QSq.jpg
https://i.imgur.com/9SNOe28.jpg
https://i.imgur.com/dKGiUSE.jpg
https://i.imgur.com/m9Quefs.jpg
https://i.imgur.com/0wn50Ak.jpg
https://i.imgur.com/kX6VxTy.jpg
https://i.imgur.com/LZ2Zi0M.jpg

So I'm pretty sure I need to replace the sway bar end links and the tie rods. Do the A-arms need to be completely replaced or can I replace the bushings only? The shock bushings don't look very good either. Also, what is the item in the last image, and does it need replacing maybe?

Thanks for the help!

 

Yes that's the white plug I was talking about. Don't know for sure but we have been told the S Type was shipped over sea's vertical with the nose down. That plug is grounded only for transportation and then never used again. Just make sure it does not ground out and tuck it out of the way.

Yes the rubber boots look like all the rest we have seen. You have several choices on that. I let them go until they wear out or make noise. Just as an example my 2005 STR has 125K miles on it and still has 100% of the stock suspension and makes no noise and has no slop. BUT I have many broken rubber boots that for sure are letting dirt and water into the joint!

You can replace the bushings only and that is slowly getting better as I "think" you can get all the suspension bushings now. There were a couple that you could not and had to buy the complete suspension arm from Jaguar and those are very expensive. But ball joints are still hard to find by themselves. The lower ones take all the wear and these are the problem. Not sure at this time if can get them separate at all? Again Jaguar wants you to buy the entire arm and there is some truth to that. We have had people mess up the bushing install and the angles required to press out the ball joints are a bit tough to do too.

Recently people have found just the rubber/plastic boots and have been changing them out. Note that won't work on the bushings only the ball joints/tie rod ends.

One last suggestion is several people use needle grease guns and regularly re-grease the broken boots.

Your struts look about right. It's OK to have that thin oily film on them. Just watch for drips as the they can leak but it's not common and the CATS units are expensive to replace.

One last suggestion? It's always better to post the pictures directly to the forum. All hosting sites will go out of business or change something in a year or two and then no pictures. You will see hundreds of great threads on this forum that now only have red X's or kitten pictures because the host site is long gone/changed.
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Thanks. Yes I think I'll wait until they wear more or make noise before I do anything. I watched that video that was shared on this forum about how to physically check the suspension components to see if they need replacing and then go from there.

If I don't have to replace any components now, maybe I'll save up for an Autoenginuity instead to save on future trips to the dealer/indy.