Have not figured out this forum page, cannot respond to you other helpful message directly. Hope this works.
Its HTML Code, the words with brackets around them make things act different, [] and then to turn off the you need [/].
Mongo53 said:
If its not pressurized enough for a dynamic load, then it would act like a soft springs. The nose would dip after going over the bump.
First thanks for the replies and ideas!
It does act like soft springs; it is very bouncy until it hits the travel limits which it does quickly with a bank.
I don't have QL, so I don't have experience. The posts I read about, in ORAII the QL is very stiff. I don't know if that is because the spring rate is high or the suspension is hitting the end of travel.
Keep in mind, the shock/struts are suppose to damp the bounciness. So by bouncy you mean after going over a bump, the vehicle bounces up and down several times, that is a lack of damping. Either the spring rate is too high for the shocks/struts or the shocks/struts or blown or weak and not damping enough.
Of if you mean by bouncy, the vehicle bounces once, but more than it should on every bump? Again a mismatch in spring rate and damping, either the airbags pressurized to much or something wrong with the shocks.
Mongo53 said:
Huh? That sounds like expected operation, and would indicate there is no leak? How do you conclude the opposite?
I read an article on how the system works. There is a reservoir. When the up button is pushed, a valve opens and the compressor pushes nitrogen from the reservoir into the spring shocks, first the rear, then the front. When the car reaches the correct height the valve closes. When lowering another valve opens and the compressor moves nitrogen from the spring shocks back to the reservoir in reverse order. The compressor and the valve system are one unit. When the car reaches its lower height, this valve closes. If the reservoir is empty then the car would not raise. If there is a leak in any one of the spring shocks the car would not stay raised. However I theorized that there could be a leak in the reservoir or the supply lines leading to the spring shocks but the car would remain in its height position because the valves are shut, and the nitrogen in the spring shocks remains the same. if there is a leak on the reservoir side, the reservoir and the feed lines nonetheless would be pressurized to atmospheric pressure and the compressor could pump atmospheric gas through the larger valve opening to load the spring shocks, in theory. Chrysler engineers cannot ascertain how the system works because they have not designed a way to measure the pressure in the reservoir. As I stated after a period of time the dealer did add nitrogen to the reservoir demonstrating it had lost gas since the last refill.
[/QUOTE]
Yes, that is how I understands the systems works, you're prevous post, you describe how the system reacts to being raised, which sounds like the way it should act and sadi that is why you think something is wrong with it. Which did not make sense.
The Engineers and Techs at the service department can determine how much nitrogen is in the system by doing a Mass Measurement Procedure (or term similar to that). Yes, if you have had to have nitrogen added to the system, and the techs didn't do it ignoring the published procedures (they sometimes pull this crap), if you really needed it, then it would have to be the result of a leak.
It's like an AC system, in the sense it requires a certain mass of working fluid (gas) to work efficiently and effectively. Just measuring pressures isn't effective, there are too many pressure differences in different parts of the system, pressure varies too much with the ambient conditions, etc, etc. So they come up with a test that indicates the actual mass of Nitrogen in the system. From what little I read, there is some sort of procedure they can do with the wiTech (scan) tool at the dealership using the FSM procedures to determine the mass of nitrogen in the system and service accordingly to get the correct mass.
I wouldn't put it past a dealership service department to not even open the book and just added a couple of PSI of nitrogen to the reservoir just guessing it might improve things.
Mongo53 said:
Loud Bangs are usually parts contacting each other with force behind it.
Bumpstops are designed to cushion the impact of the suspension hitting its max limits, occasionally. Since its usually a rubber/poly bumper, it will make a noticeable Clunk Noise. If you're hitting bump stops often, its not designed to do that and eventually damage or premature wear happens.
Agreed I think that happened. Tell the engineers.
Mongo53 said:
Swaybar bushings wearing out prematurely is common on a lot of vehicles. Jeep likely designed the swaybar bushings molded to the bar to make them last longer. But on the flip side, that means you have to replace the entire bar when they do wear out, which is way more expensive. Changing ride height is going to stress the sway bar bushings more than when they are at rest at normal ride height.
Agreed, yes $850 to replace the two sway bars with bushings.
Before these sway bars with the bushings molded on them, if got noise from the swaybars, typically you just replaced the end links and bushings. Didn't really worry about if only one was worn and not both, cause it only cost another $20 to replace the other while you're at to ensure no more noise from the swaybar.
So, the Dealer Service Department thinks the same thing, and it's not their money, so they quote you $850.
I had sway bar clunking, at 77k miles. I replaced my end links, since thats affordable, and prayed that it solved it and I didn't have to deal with the bushing. I was lucky, just the sway bar end links solved the problem. I did it myself for about $30. Of course I don't have QL either, and I can see how the QL stresses the bushings also.
Mongo53 said:
Has anyone figured what is causing the loud bangs? Is it the suspension contacting something, hitting bump stops, the airbags (perhaps bouncing on their mounts) or something else?
Engineers say it is banging on the bump stops. Again the new cars on their lots do not.
Have you inspected the bump stops on your vehicle? How many miles on your vehicle. Remember I said the bump stops are designed for occasional use. It's possible hitting bump stops often have chewed up the bump stops, and now they make loud banging noises, cause only half the bump stop is there. It's purely a guess on my part, but looking at the bump stops doesn't cost anything.
I suspect the bump stops on the front suspension are on the shock/strut, so you won't be able to inspect them. The rebound bump stop might be internal to the shock/strut, if so, likely it's not a very robust bump stop, and damage to the shock valving might have happened. And you say you're suspension is bouncy? Hmmm, related?
Mongo53 said:
Just doing a little simple math, at max height, there may only be 1.75" of rebound in the front suspension, with max spring rate, so I'm guessing going over bumps as the suspension rebounds, it runs out of rebound and hits bump stops.
Is it normal? It could be, but that means Jeep designed a suspension that didn't refine out loud bangs for going over bumps.
I don't know how common problems with the QL is, you can't go by internet forum posts as the statistics. People who have no problem with their QL aren't posting about it. But, there are a lot of posts and the more I hear, the more suspicious I get that it isn't really a good system or at least a durable system. If I'm right that ORAII leaves only 1.75" of rebound in the front suspension (and I could be wrong), I could see how using ORAII more than on rare occasions could result in early wear on the suspension.