Rough ride

[3redc]

Hello everyone, I have a 2008 Basic XLR that I'm having issues with. The problem is extremely rough ride. When traveling down the expressway at 50 - 70 mph everything on the surface of the road can be felt. Even to a point of severe Bump steer situations where you had better hang on the the steering wheel when you are in a slight turn. The normal ride is very hard and rough to a point where it's not fun to take the car on any sort of weekend trip. I'm running Goodyear EMTs @30psi, tires are perfectly balanced and I recently had a 4 wheel alignment. I've checked to make sure there was no spacers left on the shocks and all electrical connections were secure and tight.I know EMTs do right rough and the ride is noisy but this is extreme. I also have a 2002 Corvette with the same tires and the ride is completely different. My main question is is there any ride adjustment via computer if not is there any way of checking if my shocks to see if they are good or not. I have 55k miles om my car and never been in any accident. I love the XLR but right now it's not fun to drive. Any help or information would be appreciated.
Thanks for your time.

 

[Stella]

There are acouple things you can check. First check all four shocks for leaking. They shouldn't have fluid coming out of the shaft area. Then check the rebound of the shocks push down on each corner of the car. You should get a quick rebound "not stay compressed". Then check your mono springs front and rear. To check look at the spring there shouldn't be any freying of the spring composition. Should be smooth and no cracking. Then check the bumpers on the ends of the mono springs. These give you your ride height. Some have had these bumpers ripe off. They can be replaced individually look for them for a c6 easily found. That's where I would start hopefully problem exist there. Good luck let us know what you find

 

[graytoad]

Just a thought: do you know the history of the car? Any chance the car was 'raced' etc. AKA: any possibility the previous owner had the shocks switched out for a far stiffer set? I am going to assume a Caddy dealer could check to see if they have the proper part number etc.

 

[ccclarke]

--Just a thought while you're under there getting acquainted with your shocks; take a few moments to inspect your composite transverse leaf springs, and the accompanying adjuster bolts. The bolts have pads on the ends that can degrade over time, and the leaf springs can crack, rendering the ride as horrible as you've described. The shocks are the most likely culprit though.

CC

 

[3redc]

Rough Ride

Well I just got out from under the car and installed front wheels. The shocks are stock GM, no oil seepage at all (dust on the top of shocks) and the rubber height adjustments at each end of the spring are like new no deterioration. The front spring has no damage at all. The car really doesn't look like it's 7 years old. However I did notice that there was a cable rubbing on the electronic position sensor on both sides of the car. I'm wondering if that could cause a false reading. It's raining out now or I would test drive it. Any thoughts anyone?
Thanks...

 

[3redc]

Also I noticed when I push down on the front corners of the car there is very little movement. Comparing with my Corvette it's about twice the resistance. The whole car seems very tight. I guess I'll have to bite the bullet and take a trip to the dealer and have it checked out.

 

[pure zen]

question,,,

You haven't mentioned 'how many miles' on your GY EMT tires....

I've had several sets of those tires on other cars I've owned.......ride becomes rougher as they wear down due to hard & heavy side wall construction.
Probably not your problem, but was curious as to the mileage on your GY tires.

p z

 

[6444johnf]

Did this condition happen "over night" or has it always been this way? My 2008 has a silky smooth ride on our great southern roads. When pushed the ride does firm up quite substantially. Wish I could point you in some direction!

 

[3redc]

There is aprox 3k on the new EMTs Goodyear run flats. It really seems this problem started like overnight. The ride was never so bad that I didn't enjoy driving it.I love the car but lately it just sits in the garage.

 

[pure zen]

It really seems this problem started like overnight.

Hhhmmm,,,,, Now I'd be more inclined to refer back to CC's post > check out ,,,,,"composite transverse leaf springs, and the accompanying adjuster bolts"

jmo

 

[3redc]

Hhhmmm,,,,, Now I'd be more inclined to refer back to CC's post > check out ,,,,,"composite transverse leaf springs, and the accompanying adjuster bolts"

jmo

I went over the both front and rear composite springs with a fine tooth comb no damage what so ever. The prior owner of this car was in his 80s I don't believe he would have changed any suspension parts to change the ride. No logged maintenance report from the Cadillac dealership of anything to do with this issue.I hate to do it but I guess i'll bring it to the dealership tomorrow and get there opinion.

 

[lextoy]

control module for suspension died? or some wire loose somewhere?
if it rides that bad all of a sudden, and the mechanical suspension parts all in good condition, sounds like the magnetic ride control (MRC)
isnt working properly. suspension module is in the trunk compartment with the top hydraulic system.
if its twice as hard as a vette and not much movement , sounds like the MRC suspension is in full down position, like its off?
need to get codes pulled.
did water get into trunk compartment lately?

read this
https://www.xlr-net.com/forums/cadi...ried-folding-top-and-ride-control-module.html

could also be a bad connection or worn wire somewhere, there are two wire connector clips to each shock(i think) and i am sure other connections at the module etc...
is the car sitting lower at one corner or front to back, or all the way around????

 

[3redc]

control module for suspension died? or some wire loose somewhere?
if it rides that bad all of a sudden, and the mechanical suspension parts all in good condition, sounds like the magnetic ride control (MRC)
isnt working properly. suspension module is in the trunk compartment with the top hydraulic system.
if its twice as hard as a vette and not much movement , sounds like the MRC suspension is in full down position, like its off?
need to get codes pulled.
did water get into trunk compartment lately?

read this
https://www.xlr-net.com/forums/cadi...ried-folding-top-and-ride-control-module.html

could also be a bad connection or worn wire somewhere, there are two wire connector clips to each shock(i think) and i am sure other connections at the module etc...
is the car sitting lower at one corner or front to back, or all the way around????

The car is sitting perfectly level, trunk is bone dry. I checked all the wiring I could and the connectors and they all look fine and tight. This sounds like this could be the problem.I'm making an appointment today at the dealer. Thanks for your time.

 

[ccclarke]

In most cases, if the Suspension Control Module fails, a DIC message will alert you. Failed shocks don't necessarily prompt alerts.


CC

 

[3redc]

In most cases, if the Suspension Control Module fails, a DIC message will alert you. Failed shocks don't necessarily prompt alerts.


CC

Is it possible all 4 shocks have gone bad at the same time? None of them are leaking at all, and when you push down on the corners of the car it's very stiff with very little give in the suspension. Will a tech II tell weather the shocks are bad or not?
Thanks..

 

[lextoy]

my bet is shocks are fine, something else went haywire. maybe some sensor, or module is misreading something.
techII should be able to determine what is wrong.
need a competent technician to check, not just some service writer to tell you you need 4 new MRC shocks etc.
dealers are dangerous cuz they tend to like to spend tons of your money on unrelated issues.
then eventually after they put on thousands in parts, do the module relearn, or whatever, that is all they really ever had to do from the get go.
beware.

 

[3redc]

my bet is shocks are fine, something else went haywire. maybe some sensor, or module is misreading something.
techII should be able to determine what is wrong.
need a competent technician to check, not just some service writer to tell you you need 4 new MRC shocks etc.
dealers are dangerous cuz they tend to like to spend tons of your money on unrelated issues.
then eventually after they put on thousands in parts, do the module relearn, or whatever, that is all they really ever had to do from the get go.
beware.

I very much agree. I'm going to check any little things like fuses etc before I bring it to the dealer next Wednesday. This thing has really taken it's toll on me. I have babied this car for the last 5 years and it's been one thing after another. I can't wait to see how much this problem cost me.
Thanks for your time.

 

[3redc]

Well I received the bad news about my car today. After a trip to two dealers it seems they both came up with the same answer. First of all two of the shocks need replacing, second the Electronic Control sensor located in the trunk could have gotten wet at one time (probably before I owned it) and it's giving out weird signals to the rest of the car. Both dealers can't guarantee that will take care of the problem. The cost estimate for replacing two shocks and the position sensor is over 3K. That ain't going to happen. So after a lot of sole searching I decided after 4 years of back and forth to the dealer for everything from battery failure, steering column, top issues, taillight and headlight problems, locked out of my car in Canada, the list goes on. Bottom line is I opted to trade it in. It broke my heart I really loved this automobile but I guess it didn't feel the same about me. It was the sharpest car my far that I ever owned but it was time. The dealer through a great deal at me that I couldn't pass up. The XLR is a high maintenance car even if you only put 2K a year like myself. I purchased a CTS V all black and I love it. I'm going to miss driving my XLR a lot but it is what it is. I want to thank all who gave me there support and ideas to try to remedy this issue it was appreciated all your input. I met a great bunch of people at Bowling Green two years ago and had a lot of fun. The good news I'm still a Cadillac owner.
Thanks,
George

 

[graytoad]

Well I received the bad news about my car today. After a trip to two dealers it seems they both came up with the same answer. First of all two of the shocks need replacing, second the Electronic Control sensor located in the trunk could have gotten wet at one time (probably before I owned it) and it's giving out weird signals to the rest of the car. Both dealers can't guarantee that will take care of the problem. The cost estimate for replacing two shocks and the position sensor is over 3K. That ain't going to happen. So after a lot of sole searching I decided after 4 years of back and forth to the dealer for everything from battery failure, steering column, top issues, taillight and headlight problems, locked out of my car in Canada, the list goes on. Bottom line is I opted to trade it in. It broke my heart I really loved this automobile but I guess it didn't feel the same about me. It was the sharpest car my far that I ever owned but it was time. The dealer through a great deal at me that I couldn't pass up. The XLR is a high maintenance car even if you only put 2K a year like myself. I purchased a CTS V all black and I love it. I'm going to miss driving my XLR a lot but it is what it is. I want to thank all who gave me there support and ideas to try to remedy this issue it was appreciated all your input. I met a great bunch of people at Bowling Green two years ago and had a lot of fun. The good news I'm still a Cadillac owner.
Thanks,
George

Sorry to hear of all your trouble and ultimate 'disposal' of your car. You gotta wonder why one car can give so much grief yet other cars (like mine---- knock wood) are so trouble free. I am sure you will love the CTS V and hopefully have many years of trouble free driving.

 

[pure zen]

the money pit,,,,

George,

I agree, you made the right decision to trade it off. No sense pouring $3K more into a car that the service departments couldn't guarantee to solve your issues. I never want to pay for guesses. The dealer probably won't fix it either, and just wholesale it off to some small, independent sled lot or take it to the auction. The next owner will figure it out that they bought a lemon or tired horse with problems....

Enjoy the CTS..

p z