Air Suspension Problem while fully loaded

M

MindyMark

Registered
The air suspension is new to me, and I don't think this question has been asked, so please excuse me if it has.

This only happens occasionally when the car is fully loaded with 4 adults. Right after starting the car it feels like the car is running rough, similar to a miss in the idle. After about 30 seconds the Check Air Suspension message appears on the message console and the car starts to runs smooth.

It's my understanding that typically means the air compressor overheated due to leaky bags or a under performing air compressor. The system doesn't seem to have a leak it in, at least not a major one. The longest I have waited to do a leak test was about 2 hours and it didn't drop any.

Other the the occasional noise it makes when it when the car is full, the air suspension seems to work just as it is supposed to. Only thing I am not sure of is that the air compressor comes on occasionally in around town driving when I haven't reached more 55 mph when the car is supposed to lower.

Would it be considered normal for the air compressor to come on during around town driving?

Any idea what would be causing the car to feel like the car is missing right before the Check Air Suspension message comes up?

Thanks for you help! Looking forward to helping other members with their problems, I love these MN-12 cars!
 
This is just a guess (I'm sure others will wade in) but it sounds like you are stressing the compressor to the max, and then the battery is on its last legs or has poor connections.
 
Sadly, it sounds like the suspension compessor may be struggling. I'd suggest browsing www.americanairsuspension.com and the suspension forum here for more insight.

Specifically the Check Air Suspension message appears 90 seconds after starting the car if the compressor times out and the car has not reached trim height. The Check Air Suspension message appears 45 seconds after starting the car if the suspension is 'venting' and the car has not reached trim height.

Additionally, the more active than normal cycling of the compressor indicates the vent solenoid valve could be corroded.
 
I'm curious about the battery comment. I know I need a new ground battery cable as it is pretty corroded. You think that could be part of the issue?

And I think it's closer to 90 seconds rather then the 30 I had in my first post.

I was on the air suspension website the first night I had the car. :) That's when I learned enough to start asking questions without looking like a fool.
 
A ground cable is as important as the hot cable. It is the return path to the battery ...without it, no power.
 
Agreed! I am a firm believer in extra clean battery post cable connections.
I always clean the post and cable ends with the wire brush made for that purpose, and always install the little anti corrosion rings on reassembly.
 
Well the first 5 inches or so of the cable is totally corroded. It was on my list to replace, as I don't think I can cut out the bad part and still have enough length to re-terminate it.

Is replacing the negative ground cable easy to get it? I notice it gets bundled in with other wires and looks like it might be some work to unbundle it. Of course I don't have to route it the same way it was from the factory.

Just thought I would get your all opinions first.....
 
Cut the old one off as flush as you can. Install new one to a good solid bolt on the block. If you can install a smaller ground leading to the chassis somewhere from the battery...
 
Last edited:
MindyMark said:
Is replacing the negative ground cable easy to get it? I notice it gets bundled in with other wires and looks like it might be some work to unbundle it. Of course I don't have to route it the same way it was from the factory.

Just thought I would get your all opinions first.....
Click to expand...

It's almost impossible to get to the end of the ground cable at the block. Its next to the drivers side motor mount. I was going to replace mine but I wussed out.
 
I've noticed those small ground wires before. My 90 Cougar had some very weird issues when that connection became flaky.

Does the ground from the block not provide a complete ground, thus the need for the one to the chassis?
 
Makes sense.

I'll get under that beast sometime soon and work on a new ground cable plus the additional one.

Then I'll just need some fatties to come load in my Mark to see if acts up. :)
 
That's one other thing that could be your problem....go here to see how your air ride system works and how you may have a leak in your system sometimes and not others. http://www.americanairsuspension.com

It amounts to when a fold in the air bag leaks when it is exposed, but does NOT leak when it is folded in on itself.
 
Thanks, I've been all over that site already. The air suspension system doesn't sound nearly as complicated as I expected it to be.

I'll keep an eye on it for a while, as I've only owned the car a week so I'm sure I"ll find a few more oddities. I'll keep this thread updated when I get more information.

But I promise, being the Lincoln lover that I am, I'll get her back in the shape that she should be.
 
Well I replaced the ground cable today.....that bolt was near impossible to get to. I was lucky that the Mark needed a oil change, so without the oil filter in the way it was easier to get too.


Well there was no change in the air suspension problem.

Let me revisit it and provide more details:

1. 80% percent of the time the air suspension acts normal.
2. The compressor always sounds normal while pumping up the front (front and rear pump up separately right?)
3. As soon as front gets to the required height the compressor starting making a weird noise, to the point it makes the engine sound like it is missing. (this is what I thought was happening first, until the air suspension shut itself off).

Is there a clog or something binding on the rear end? Unless I'm missing it I don't see anything on American Air Suspension's website about this particular problem.

Once the weather warms up I plan on replacing the front struts and at least the rear shocks too.
 
I think you may have several things at work here. First is that you may have worn compressor mounting bushings that are causing all the noise, espeially when the compressor has to pump up the final amount in the system. This may be putting some excess stress onto the mount system causing the bushings to fail, this would require a compressor change.

If you plan on doing the fronts and rears, I would suggest replacing the compressor and bushings along with getting a Spider Valve and you will be good to go for many years with the new system.

When you replace your Air Springs be sure to throw away the marshmellow, trim the solenoids, and replace the O Ring on the outside of it and lube with di-electric grease.
 
The spider sounds like a good idea, but why is the spider valve so expensive? I also can't seem to find it on their site anymore, they seem to be doing a redesign.

I also planned on replacing the compressor just to get it out of the way. But if I tear into it and looks fairly new I might try other things first.
 
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