My 08 GL450 is presenting intermittant heavy (difficult) steering. Usually in a parking lot after driving.
VIN: 4JGBF71E08A398130

It sounds like this is a fairly common thing, so I first looked to clean the contacts on the Speed Related Steering Solenoid -BUT- I cannot find it on my rack.
Perhaps I dont have this feature? I checked the VIN decode and dont see it listed. What is the code# if I do have it?

Can someone tell me *exactly* where I would see this Valve/Solenoid when I'm looking at the rack from underneath?
It wouldn't be on the steering pump would it?

Thx!

 

Your PS pump is probably wearing out. My lack of assist at low speed started intermittently and gradually stopped working at idle all the time. If it comes back with an increase in rpms, the pump is bad.

FCP Euro sells replacements along with the right PS fluid. (keep the original box for the core - I was charged a 20% fee because I sent it back in a smaller box to save on shipping). It isn't that hard of a job, although getting the 3 bolts loose on the reservoir is tedious because there isn't much clearance - I ended up using an allen wrench because none of my torx sockets were the right length. The snap ring is also tricky to get back on. I secured it with a piece of wire while attempting to push it back on so it didn't get lost in the depths of the engine with an unsuccessful push. You'll want to bleed the system per the service manual when you're done.

 

How’s the fluid level and is it noisy?
speed sensitive steering is option code 213 iirc.
if you have it the wire to the valve sits on the steering box knuckle.

 

Good call on the noise. Mine started making noise at/near full lock for some time before it started losing assist.

 

Yeah if there's no noise it could also be an intermittent wheel speed sensor failure telling the variable speed steering to go to hard setting.
But, depends if OP has it. Pretty sure all x164 do.

 

Gentlemen, thank you for the timely and helpful responses!

EWT:
-Thx for the idea to try extra revs! I’ll test that tomorrow.
-I have previously replaced that reservoir o-ring, so I know what you’re talking about. Not bad, but that little snap ring can be a pain…
-Extra thanks for those PDFs!!!! Awesome!

MaxBlast:
-I just checked, and to my surprise the fluid level is at the very bottom of the 20C range! I’ll add some and see if that helps. (Weird bc I just checked it not long ago & haven’t had any leaks)
-Thx for the code (213) looks like mine does NOT have that feature so I can skip wasting time searching for that valve. I’m quite surprised of this tho bc my GL450 has pretty much every option that I’ve seen available on a 450 of that year…. Weird.
-I have not had any noises coming from the PS system at all.

From these comments, sounds like it’s either a fluid level issue, or a failing pump. Will add fluid and retest tomorrow.
I didn’t think that a bad pump would produce intermittent performance like this but its interesting to know someone has experienced that.

Thanks again all. I will follow up with results.

 

Yeah if no 213 and fluid level to full has no effect, then it’s most likely the pump itself