PAS problem - maybe ??
Thread Starter
Senior Member
Joined: Sep 2002
Posts: 268
Likes: 1
From: San Diego
ML430, Mini Cooper S and Porsche 911 Twin Turbo
PAS problem - maybe ??
Well I suspect my ML430 is about to act up again after about a relatively trouble free 2 years and 20,000 miles.
Here's the symptom...
After leaving the ML stood outside at work all day, I start the engine up and everything appears ok.
However as soon as I start a low speed manouver I can feel a distinct high frequency vibration through the steering wheel and hear a high frequency whine - but only when the PAS is under load and only for the first mile or so.
By the time I get home everything seems normal.
At first I though it was the serpentine belt slipping but it wasn't.
Further once I've driven a few miles while at a standstill I can turn the steering from lock to lock with no indiction of a problem (note I would never normally turn the steering lock to lock while at a standstill !)
Any ideas ?
I'm thinking steering pump (or filter) or sell the ML quick !
Here's the symptom...
After leaving the ML stood outside at work all day, I start the engine up and everything appears ok.
However as soon as I start a low speed manouver I can feel a distinct high frequency vibration through the steering wheel and hear a high frequency whine - but only when the PAS is under load and only for the first mile or so.
By the time I get home everything seems normal.
At first I though it was the serpentine belt slipping but it wasn't.
Further once I've driven a few miles while at a standstill I can turn the steering from lock to lock with no indiction of a problem (note I would never normally turn the steering lock to lock while at a standstill !)
Any ideas ?
I'm thinking steering pump (or filter) or sell the ML quick !
Member
Joined: Dec 2003
Posts: 236
Likes: 0
I dont think it is that big of a deal. first of all check for leaks. if none. make sure your low pressure return hose (on the radiator) is not comming loose. You have had the recall done right? if everything looks good, i have been seeing the p/s resvoirs going bad for what ever reason. they are causing caviation in the pump. the resvoir is inexpensive and available seperate from the pump. try that. It should take care of your noise once you have all the air bleed out
Thread Starter
Senior Member
Joined: Sep 2002
Posts: 268
Likes: 1
From: San Diego
ML430, Mini Cooper S and Porsche 911 Twin Turbo
No leaks....
Hi ML God,
figured you'd reply ;-)
No leaks as far as I can tell (I'm sure I'd notice) and yes had the clamp update done.
I'll check the low pressure return hose, but don't expect to find anything a miss.
So will check the level in the PAS resevoir - I assume its the black filler cap adjacent to the oil filter ?
I suspect is cavitation or something similar as the PAS still feels fine - apart from this high freq vibration.
Is changing the resevoir a simple diy ? FYI I'm reasonably competent with a wrench !
figured you'd reply ;-)
No leaks as far as I can tell (I'm sure I'd notice) and yes had the clamp update done.
I'll check the low pressure return hose, but don't expect to find anything a miss.
So will check the level in the PAS resevoir - I assume its the black filler cap adjacent to the oil filter ?
I suspect is cavitation or something similar as the PAS still feels fine - apart from this high freq vibration.
Is changing the resevoir a simple diy ? FYI I'm reasonably competent with a wrench !
Member
Joined: Dec 2003
Posts: 236
Likes: 0
to change the resevoir is 1 bolt, 1 clamp and i clip down near where it attaches to the pump. the clip could be a bugger to get off and put back on. just take your time and dont loose it. dont forget to also change that o-ring
