"Haimatox" (haimatox)
04/14/2014 at 12:55 • Filed to: None
0
13|
"Haimatox" (haimatox)
04/14/2014 at 12:55 • Filed to: None | 0
| 13 |
I know I'm not the most knowledgeable when it comes to car mechanics, and I may sound like an idiot. But I digress. My mom's 2012 Mercedes ML350 has started making an occaisional hissing noise from the front left (only started yesterday). This mainly occurs when making a turn, especially a right turn. It sometimes occurs when driving in a straight line. The hiss sounds like air leaking and lasts for about 5 seconds before suddenly stopping. The hiss has grown louder in volume and more frequent since yesterday. I suspect a power steering issue, but it's occurance even in a straight line makes me doubt myself.
EDIT : Is this possibly dangerous? I should have asked this before.
Brian Silvestro
> Haimatox
04/14/2014 at 12:57 |
|
For some reason I feel obligated to comment here just because I'm in the Albany area, even though I have no useful information to share.
Arben72
> Haimatox
04/14/2014 at 12:59 |
|
Belts probably loose, take it to your dealer. You should be under warranty if it's a '12 unless you have high miles.
offroadkarter
> Haimatox
04/14/2014 at 13:00 |
|
obvious question, have you checked the fluid level?
BJ
> Haimatox
04/14/2014 at 13:01 |
|
I don't know much about modern M-B cars, but check the power steering fluid level and look for evidence of leaks around the pump. On older cars, a whining sound is common when the pump is low on fluid, but only when turning.
yamahog
> Haimatox
04/14/2014 at 13:01 |
|
Check the fluid level, look for leaks... wait, it's under warranty right?
Jeremy H formerly Kalakaboooom
> Haimatox
04/14/2014 at 13:02 |
|
I don't know a whole ton about newer Mercedes, but my supervisor has a 2011 GL450, and I know that it has that adjustable ride height stuff by airbags or whatever (love my technical lingo you know you do), so if your mom's vehicle has the same kind of setup I would look at that first. I've never seen/heard a PS system make a hissing sound, unless it was a shit ton of fluid leaking out of a pressurized hose, and then, it usually doesn't stop until everything is gone. Plus if your PS system was going out, it would take the hand of Zeus to turn that thing.
RamblinRover Luxury-Yacht
> Haimatox
04/14/2014 at 13:02 |
|
I think you're 80% there. I'm not a power steering expert, but "sucking air into power steering system" is not impossible. When you turn right, the rack is releasing pressure on the left and recovering air, not just fluid. Probably. Bad seal, IOW.
|
Haimatox
> yamahog
04/14/2014 at 13:03 |
|
I meant to ask my mom to let me check but she had to go run some errands. Yes it's still under warranty (service people couldn't replicate the issue).
|
Jeremy H formerly Kalakaboooom
> RamblinRover Luxury-Yacht
04/14/2014 at 13:06 |
|
Recovering air?
|
RamblinRover Luxury-Yacht
> Jeremy H formerly Kalakaboooom
04/14/2014 at 13:12 |
|
Your basic steering rack is a two-way hydraulic cylinder, basically. Switches between pushing fluid in one side and removing it from the other, and going the other way - an oversimplification, but generally descriptive. Pump applying suction to one side + bad or failing seal could = sucking in air. Said seal probably leaks a bit under pressure, but not as much as you might think - it's easy to be marginal between the viscosity of... well, air and a hydraulic oil. Plus, it's a seal designed to seal against pressure more so than air intrusion.
"sucking"-like sounds can also indicate a bad recovery line, but I'd expect that to make noise going both ways, not just right. Low on fluid *might* be going just one way.
|
Jeremy H formerly Kalakaboooom
> RamblinRover Luxury-Yacht
04/14/2014 at 13:14 |
|
Hmm, alright. I appreciate the explanation, I honestly don't know too much about power steering racks, just how to diagnose some problems with them, my knowledge with them is pretty limited.
|
RamblinRover Luxury-Yacht
> Jeremy H formerly Kalakaboooom
04/14/2014 at 13:18 |
|
They vary a good bit in design specifics, really. I think some operate more like a push one way/ pull the other way, but I think my description is probably most generally correct.
LuczOr
> Haimatox
04/14/2014 at 14:16 |
|
If it's under warranty, just drive it till it really starts making a racket and then take it in to service.