2015 QX80 Rear Suspension issue...Sagging in the back (air suspension not working)

Bender13

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Hey everyone. I just recently noticed the rear is no sagging down (just suddenly noticed it one morning). The Vehicle rides fine, but obviously not good to keep as is. Looking at local places, it seems like they don't want to mess with the infinity air suspensions. I can take it to a bigger city 2 hours away and probably pay an arm an a leg to get it fixed. Anyone have the same issue OR has anyone made the change to a standard non-air suspension kit? I can't seem to find one for the AWD with the deluxe package (one place highlighted theirs does not work with the deluxe package that has all the bells and whistles). Any help/suggestion is greatly appreciated!
 
At least you’re running into shops who are being honest about not knowing how to work on or diagnose the suspension system on the Z62 QX80/56. I’m sure the HBMC suspension scares them away but it’s actually a dated hydraulic system similar to what MB first utilized in the early 90s.

Our trucks have a rear air leveling system and 99% of the time when the rear end sags, continuously inflating or not inflating at all, the air compressor is at fault. It’s the same, exact compressor that Nissan was using even on the first gen trucks. The only difference is the mounting bracket and filter plugged into the chassis. The most common failure on these compressors is the exhaust valve solenoid inside the compressor that has the tendency to seize up.

If not the dealership, a reputable independent shop with a full range scan tool should be able to do the work for you. There is a reset/relearn procedure to set the correct height within specs after installing a new compressor or any parts related to the rear air leveling system.
 
At least you’re running into shops who are being honest about not knowing how to work on or diagnose the suspension system on the Z62 QX80/56. I’m sure the HBMC suspension scares them away but it’s actually a dated hydraulic system similar to what MB first utilized in the early 90s.

Our trucks have a rear air leveling system and 99% of the time when the rear end sags, continuously inflating or not inflating at all, the air compressor is at fault. It’s the same, exact compressor that Nissan was using even on the first gen trucks. The only difference is the mounting bracket and filter plugged into the chassis. The most common failure on these compressors is the exhaust valve solenoid inside the compressor that has the tendency to seize up.

If not the dealership, a reputable independent shop with a full range scan tool should be able to do the work for you. There is a reset/relearn procedure to set the correct height within specs after installing a new compressor or any parts related to the rear air leveling system.
Thank you VERY much! This is extremely helpful! I did find a place that sounded like they work on them...but said they would need to run a bunch of tests on it and have it for an hour or so...quoted $130++ to the diagnosis...does that sound right or a ripoff? lol
 
Unless you know someone that personally has a full range scan tool or access to one, you’re faced with spending a (X) amount of $$$$ for diagnostics. Just confirm with the shop if they have access to Nissan/Infiniti’s OE service manual because it specifically notates the process of diagnosing, resetting and relearning the rear air leveling system.
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Unless you know someone that personally has a full range scan tool or access to one, you’re faced with spending a (X) amount of $$$$ for diagnostics. Just confirm with the shop if they have access to Nissan/Infiniti’s OE service manual because it specifically notates the process of diagnosing, resetting and relearning the rear air leveling system.
ok perfect! Thanks again! Taking it in tomorrow. :)
 
My 2014 QX80 was sagging. I checked the air compressor, it was bad. Got one on eBay. Replaced it. Working fine now.
 
My 2014 QX80 was sagging. I checked the air compressor, it was bad. Got one on eBay. Replaced it. Working fine now.
ok good to know! I have a local place replacing the Rear Hight Sensor as that went out. When that gets in we will see if that fixes it....if not, they will at least be able to go form there to see what may be the issue.

FYI, I wanted to update (incase it helps anyone else). The shop was able to find a rear height sensor, get it replaced, and that corrected the issue. They charged $680 total which is of course a lot of money, but overall pretty reasonable relatively speaking. Hopefully that is all that I have to deal with for a while in that. At least I know that may be the main issue if it happens again before having to go with thousands of dollars for a whole new system. Thank you all for your help!
 
While my vehicle was in for service at Nissan, the technician stated that the rear of my vehicle was sagging and it was due to a faulty air ride compressor. Nissan replaced the air ride compressor and re programmed the level height to fix it. The total for that was $965.00. The part was 393.88. The rest was for labor. A symptom that i experienced was that when the vehicle was turned on, i would hear like a motor/compressor trying to work in the rear of the vehicle but nothing happened. It was just a sound for about 10 seconds then it would go away. When the compressor was replaced, that sound at startup went away. The car no longer looks like it's sagging and looks great! I don't know if it's a complicated job or not, but Nissan did it with no problem!
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My 2014 QX80 was sagging. I checked the air compressor, it was bad. Got one on eBay. Replaced it. Working fine now.
My compressor (2016 QX80) sounds like 2 rocks tumbling in a can every time it turns on! Dealership says its "normal". How did you know yours was bad? Did you replace it yourself? Was it easy to do?
 
If anyone here has any information that could help out, it would be greatly appreciated.

I've talked to 2 dealerships,one said they see nothing wrong with the air compressor. They also said it could make that noise because it has dirt around it or, maybe it has rocks in it. The second dealership; when asked if they could replace it, said they needed to diagnose it first to verify that it is the problem. If they don't diagnose it, they cant warranty the work. I asked what criteria needed to be met for it to be replaced, there was no definitive answer-I was told, "I'm not a tech." So...I have a compressor that is failing and we are heading off on Friday to Tennessee for 9 days. CAA/AAA membership might get some usage!?
 
im sorry to hear you are not having much success with the dealer.

sadly, not much those over the internet can provide with the sparse info given. if you want to submit a video/audio of the issue, that may be helpful as it can give an idea of what it could be.

is your vehicle sagging? is the compressor running all the time when the key is on/in start? did you just buy the car or have you had it a while/bought new? when did this sound start? was it gradual or all at once? any mods done to the suspension? anything else wrong with the car?


you can always purchase a new one and replace it yourself or if you are not mechanically inclined, get. trd party.
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The compressor shouldn't be turning on every time you start the truck. If it does and there's no additional load in the cabin or rear hitch, then either a leak in the system or most likely the notorious C1803 exhaust solenoid (compressor).

Just a FYI for those DIY'ers that may run into this issue and want to save yourself an extra $100-200. The air leveling compressor for the first gen WA60, JA60 trucks is the SAME, EXACT compressor used on the Z62s. Only differences are the mounting bracket and air filter that plugs into the chassis. Remove the first gen mounting bracket from the new compressor and use the Z62's mounting bracket; same with the air filter.
 
Fairly new Infiniti owner here. It's a 2017 QX80 w/ ~37K miles. Noticed some sagging on the rear suspension the other day and I'm glad I found this thread!

I'm a DIYer and was wondering if any of you had any thoughts on whether the Rear Height Sensor or the Compressor itself might be my problem.

Symptoms
  • Sagging is equal on both sides
  • Air bags don't look deteriorated after visual inspection
  • Sags gradually when turned off and at rest
  • Inflates and lifts ~1.5 inches upon starting and driving
Any thoughts or experience with these symptoms? Thanks in advance!
 
Fairly new Infiniti owner here. It's a 2017 QX80 w/ ~37K miles. Noticed some sagging on the rear suspension the other day and I'm glad I found this thread!

I'm a DIYer and was wondering if any of you had any thoughts on whether the Rear Height Sensor or the Compressor itself might be my problem.

Symptoms
  • Sagging is equal on both sides
  • Air bags don't look deteriorated after visual inspection
  • Sags gradually when turned off and at rest
  • Inflates and lifts ~1.5 inches upon starting and driving
Any thoughts or experience with these symptoms? Thanks in advance!
Welcome! Mine ended up beging the Rear height sensor. However, It still slowly goes doesn after sitting or driving for long periods. It now at least raises every time I start the car (thanks to replaceing the rear hight sensor). So, I'm thinking I may have a small leak in the lines or bags.....Not 100% sure though...It is annoying though
 
Welcome! Mine ended up beging the Rear height sensor. However, It still slowly goes doesn after sitting or driving for long periods. It now at least raises every time I start the car (thanks to replaceing the rear hight sensor). So, I'm thinking I may have a small leak in the lines or bags.....Not 100% sure though...It is annoying though
Yes, very annoying! It’s going to drive me nuts until I figure it out. Might bite the bullet on a new compressor. It’s more likely a small leak would be coming from internal compressor parts that might not be seating properly than it is to be coming from a hole in some line.

I’ll let you know what I come up with!
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Welcome! Mine ended up beging the Rear height sensor. However, It still slowly goes doesn after sitting or driving for long periods. It now at least raises every time I start the car (thanks to replaceing the rear hight sensor). So, I'm thinking I may have a small leak in the lines or bags.....Not 100% sure though...It is annoying though
Its possible the shop didn't do the "standard vehicle height setting" after installing the new height sensor.
Yes, very annoying! It’s going to drive me nuts until I figure it out. Might bite the bullet on a new compressor. It’s more likely a small leak would be coming from internal compressor parts that might not be seating properly than it is to be coming from a hole in some line.

I’ll let you know what I come up wit
If not Nissan and their Consult diagnostic tool, a reputable shop with a full range scan tool should be able to read what DTC(s) are stored for the rear air leveling suspension.
 
Yes, very annoying! It’s going to drive me nuts until I figure it out. Might bite the bullet on a new compressor. It’s more likely a small leak would be coming from internal compressor parts that might not be seating properly than it is to be coming from a hole in some line.

I’ll let you know what I come up with!
I'm very curious to hear what you've found out so far. I have a 2014 QX80 with a slow leak as well. Compressor kicks on as it should and seems to be operating properly, it raises the back up to @ 35" at the wheel wells but will eventually drop down an inch or so after about an hour.

I recently took the family on a 4 hour road trip and when we first start out and the shocks are full of air, all is fine. But when the shocks loose air after about 30 minutes I can really tell a difference in the steering. It feels loose, wants to wander and requires constant attention.

I've sprayed soapy water on everything but I can't find any leaks from what I'm able to observe. I went ahead and bought a generic replacement compressor ($250) which should arrive next week, hoping that will solve the problem. If not, then I suppose the next step would be to replace the shocks ($600 each).

I'll update my progress as well if it's helpful.
 
Hi everyone, today while having my winter tires changed I was shown these leaking areas. I was told the compressor was working okay, though I needed to replace all the lines and suspension. Cost $4,600 + tax Canadian. Ideas? Is it worth trying to just replace the gaskets in the leaking lines on both sides (they said it wasn't worth it)? Or go to a mechanical system? It's a 2016 Limited QX80 with 70,000km on it, in the Toronto area.

Hi everyone, today while having my winter tires changed I was shown these leaking areas. I was told the compressor was working okay, though I needed to replace all the lines and suspension. Cost $4,600 + tax Canadian. Ideas? Is it worth trying to just replace the gaskets in the leaking lines on both sides (they said it wasn't worth it)? Or go to a mechanical system? It's a 2016 Limited QX80 with 70,000km on it, in the Toronto area.
Looks like I can't go to a mechanical system because I have the deluxe technology package which includes a hydraulic suspension in addition to the air suspension (which I understand is incompatible w/ the strutmasters system).

While they showed me the leak in Oct, my compressor does not stay on for very long, and the vehicle still seems to stay fairly level. I still wonder if I could just replace the hoses that are leaking...or clamp them or something.
 
I have a 2016 QX80 wit a sagging rear suspension. I have checked the fuses and the set to be ok. I don't have a CK SUSP light on my dash. I've tried the DIY checks on YouTube but nothing works. I can't find the air ride compressor relay which in supposed to be on the engine compartment. Anyone have any suggestions?
 
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