M1 ATF in MB E430 Power Steering

[HTSS_TR]

My 2000 MB E430 makes a light whine when engine is hot after driving around 15-20 minutes or so, when the engine is cold it's very quiet. MB recommends either their Power Steering Fluid or Dexron III fluid for 2000 E430. Since M1 new Multi-Vehicle Formula ATF is compatible with Dexron III and it is synthetic fluid, I decided to use it instead of Dexron III.

I tried to suck out as much old PSF in reservoir with a turkey baster, I could only suck out about 5-6 oz and replaced with M1 ATF. I'll repeat this sucking and refill until a quart of M1 ATF is in the power steering system.

I'll update how the E430 steering system responds to M1 ATF.

 

[bmwtechguy]

It will be good hear how this fluid does in your PST system.

I have used Lubegard's pwr steering additive with success to quiet some pump noise. In warmer climates a heavier fluid can help also. I used some leftover Amsoil (5W-30) hydraulic oil-ATH was the product code in a noisy Ford pump and this made it much quieter, and it stayed in there all year, no problems.

 

[mechtech2]

For a bit of real life PS experience, in the past we have used a shot of STP in a number of Fords with PS noise, and it usually makes it better.
[Not everyone customer is able[$] to get new parts and procedures.]

 

[HTSS_TR]

Updating.
After several siphons over 3 weeks, 1 quart M1 Multi-Vehicle Formula ATF is in the Power Steering System. The whine when turning the steering while the engine hot is about 60-70% less than before.

I don't know what else to try to eliminate the whining noise from the power steering system. The noise is heard only when the steering is turning more than 15-20 degree while the engine is hot after driving more than 10 minutes. It makes no noise when the car is going straight or the steering is turned at less than 10-15 degree.

 

[cos]

HTSS_TR,

Was the old PS fluid you removed factory fill?

 

[HTSS_TR]

It was changed about 3 years ago with MB PSF, along with ATF, brake fluid, coolant fluid, spark plugs (16 of them) ...

The power steering system was quiet as before that change, the noise only started several months ago.

If the whine does not subside the next few weeks, I may change it out with Dexron III.