Low corner - leaky air strut?

[beatle]

I just went into my garage to get something and noticed that my passenger front wheel looked lower than normal. I have the air suspension set to low at all times, but this looked even lower. I have stock 245/45/19 tires and the suspension is stock. The passenger measurement from the ground to the edge of the fender is 27 1/4" and the driver's side is 27 5/8".

My guess is that the passenger front air strut has a slow leak. I haven't driven the car since Saturday.

Any other suggestions before I make a service appointment? I have the + suspension, so I'll double check the part numbers before/after if they do end up replacing it.

 

[George Marley]

Maybe check your life insurance?
Air Suspension failure with very unpleasant results
Submitted by DBlueS85 on Thu, 2015-07-30 12:25
First the good part: Tesla 1-800 roadside folks were very good, the tow-truck driver was very good, and the service center was very good in repairing my Tesla in one day and then delivering it back in the evening. All very good, and I am enjoying the car again.

Now for the bad part: The right front air strut failed due to a leak which caused the whole front of the car to drop so much that the wheels were rubbing against the inside of the wheel well, and the front of the car was rubbing on the ground. The car became absolutely not drivable. Luckily I was parked when this happened. The tow truck driver could only do inch-by-inch turns to orient the car to face the tow truck, and then had to move it up again inch-by-inch using wooden blocks just so the wheel well and the bottom would not get damaged.

Why doesn’t Tesla air-suspension design incorporate some sort of a stopper to stop the car from going lower than the lowest functional air-suspension setting? The service center tech had the same idea!!!! At least it would be drivable when the system failed. I am very concerned how the car would handle if this air suspension failure occurred while driving 70 mph.

I hope a retrofit kit comes out soon for all of us with air suspension. Given my experience, I can't recommend getting the air suspension feature to anyone buying the car until there is some sort of a mechanism to allow for a controlled safe system degradation when it fails.

 

[beatle]

Mine isn't that low. It's low enough that I can no longer fit my hand in to check for clearance, but my girlfriend was able to check and did not feel the tire contacting the control arm. Not sure if that's the first point of contact, but it seemed like the closest place.

This is my first car with air suspension, but like the others I'm surprised that there isn't some kind of bumpstop incorporated into the system to keep the damper from completely collapsing.

 

[beatle]

I made a service appointment this morning, though it's not until 8/3. The suspension had dropped another 1/16"

I drove the car a couple hours ago and noticed that as soon as I started it, the low corner came up. I measured again when I got home and the suspension is higher than before.

Driver front: 28 27/32"
Pass front: 28 23/32"

Difference between the two is only 1/4" now which is not really noticeable, however it is interesting that the car is over an inch and a half higher than yesterday's measurements. It's possible that my garage is not perfectly level and that is causing the 1/4" difference if the car always seeks true level.

FWIW, I am measuring with a Bosch laser measure which is pretty darn accurate down to 1/32" or so.

 

[GHammer]

I had a similar issue with my P85+. After being away on vacation for a couple of weeks I came home to find the left rear corner noticeably lower. When I went to go drive it, it took quite a while and several compressor cycles to re-level the car. I repeated the test by driving my other car for a week and sure enough the same corner sagged over that week. SC confirmed the leak and replaced the strut, just under the wire for my warranty.

 

[George Marley]

That's all well and good but WHY don't they have any limit stops on the suspension?
That sounds like madness to me.

 

[beatle]

I'll ask the mobile tech on 8/3. Bump stop size and material can make a huge difference in handling and comfort.

 

[Aggmeister2010]

You *might* have a leak, but honestly the Air Suspension sensors aren't laser precise all the time....and given that you're only off by 3/8", it could just be that it needs to cycle the heights.

Trust me, I can totally relate to the frustration of not being perfectly level - I'm a huge coilover fan for exactly that reason - but you should try this before sending the car in for service:

Measure your ride heights in every corner before leaving your garage. Put it in STANDARD height, the back to LOW, and remeasure. See if they have changed. If they changed, you may have a leak.

If not, you may just need to cycle it to re-calibrate. Go to a level surface. Don't assume your garage floor is level...for example, mine looks level but isn't. I'm talking about a large parking garage top floor or something with a large surface area where you can get a better visual that the surface is actually level.

Measure your ride heights on each corner. Go to the suspension settings page in your MCU, and go LOW > VERY HIGH > LOW > VERY HIGH > HIGH > STANDARD > LOW. Remeasure your ride heights.

This runs the sensors through the full scope of their usable range, and will sometimes help get your car sitting pretty again.

 

[beatle]

The thing that tipped me off to even look was not the difference in height, but that the passenger side was pretty slammed. I'd never seen my car that low, and it had not been driven in 5 days which would have allowed a fair amount of air to leak out. I've actually been driving the car somewhat regularly lately so I haven't been able to measure the drop under the same conditions, but after another day or two, I will check by adjusting the suspension and remeasuring.

The car has currently been sitting for about 37 hours, so I went to measure the passenger side. It is 28 1/2" now. That's only slightly down from the "freshly driven" height of 28 21/32" but still quite a ways off from the initial 27 1/4" that drew my attention in the beginning.

Tesla has already made the call to order a new damper, so there must have been compelling evidence to indicate a leak. I'll continue to monitor though. I am mostly curious as I plan to keep the car past its warranty period, and I want to be able to identify these kinds of failures in case I need to replace a strut myself. I can't really afford to throw parts at a problem when they cost as much as this is likely to cost!

 

[SilverString]

Pretty common in any air suspension at some point. Happened to my XJ8 twice - leak was usually coming from the strut itself - if you can get to it check it like a bad tire by pouring water over it and looking for bubbles. In my experience if it is a leak in the air line anywhere the entire car will sit low, not just one corner. Good luck!

 

[beatle]

Down to 27 15/16" just now. This is 66 hours after being driven.

 

[demundus]

If you had a leak, the compressor would attempt to level the car. Despite what another poster said, the leveling system is pretty darn precise. I installed the leveling link upside down on my rear control arm once and the car refused to do anything the sensor wouldnt allow it to do, it just rode lopsided until i realized it. If the car is creeping down on the sensors, they would kick in and try to run the compressor, and you would know...

 

[beatle]

It levels the car out when I go to drive. When it sits, it drops. I don't think the car makes any effort to adjust itself while it is idle.

 

[demundus]

It levels the car out when I go to drive. When it sits, it drops. I don't think the car makes any effort to adjust itself while it is idle.

The car is constantly trying to level when driving within a margin of error and maintained at some X period of time at a height it deems too high or low. It will attempt to level while idle under the same conditions. Thats an impossible test to consider without actually having access to the diagnostics. The measurements are in 1/10th of inches for the leveling software. It reads all 4 corners continuously, and has a programmed set height for each setting. It attempts to balance within that fraction of an inch when NOT driving, and still for some period of time (i dont know exactly how long).

 

[beatle]

Tesla hasn't communicated with me about what they found specifically, but they ordered a replacement damper to fix it. I will ask them how they were able to diagnose this (assuming they got it right and I do have a leaky strut).