Lop sided front spring suspension
 

Greetings all, I’ve been a member here for a little while after purchasing a 2004 E53 diesel sport recently.
So far it’s been a great car however; recently I noticed that it has a lean towards the left side.
I’ve measured the ride height on each of the four corners and the problem seems to be originating from the front left which is about 30mm (a little over an inch) lower than the front right.
I understand this vehicle has airbag suspension in the rear and a conventional spring setup in the front.
I’ve done a search on this forum to see if this was a common problem, but 99% of the threads I found were in relation to airbag suspension and the remaining threads weren’t really all that helpful.
Has anybody experienced a similar problem or knows what the common cause(s) are of a saggy conventional spring front suspension on one side ?

broken spring?

Could it be a bad level sensor in the rear? Maybe the right rear air bag has pumped up too much air causing the left front to go down?

park it in your garage or find a level surface put rear on jack stands (make sure they are same height) and then measure your front if it's the same u will know it's not your springs ....maybe that will help narrowing that down good luck...and when it comes to your sensors peak code reader is a good tool to let you know if your sensors out of wack
even if its not showing up on your dashboard display...

Thanks for all the suggestions so far.
I don’t believe it’s a broken spring as I’ve had a pretty good look although, I guess it’s possible it may be broken at the very top or bottom where I can’t see.
For the time being I will attempt to isolate the problem being definitely on the front or rear.
The only reason I suspected it was the front was that it had the most variation in ride height from side to side on level ground. Thinking a bit more about this, it may simply be because the front is the heaviest end of the car.
The suggestion of lifting the rear equally on each corner off level ground and measuring the front is a good one.
I will do this and report back on what I find as I believe this will conclusively prove which end is causing the problem.

Could be a partially collapsed front spring. Real fix is to replace them as a pair, I think. Had this on a small Pontiac years ago. You can sometimes find the twist-in lugs for a temporary fix. They just twist into the space(s) between the coils of the spring to jack it back up, and ride there. My experience was that they were a decent, cheap, temporary fix. But, I worried about the increased risk of further spring failure due to the lugs placing increased stress on a smaller portion of the spring. So, I eventually replaced the springs.