500E Tandem pump pulley spins freely / Rough idle

[dinbirb]

Hey guys,

Need some help with my 500E. I noticed a hydraulic leak on the undertray, but the top of the engine looks dry.

The weird part: I can actually spin the pump pulley by hand with the belt still on. It just spins freely without moving the belt at all.

Also, the engine is running pretty rough since i noticed the noice of the pump and that the hydraulic fluid leaked. Could these be related?


Thanks!

 

[gsxr]

If you can turn the pulley by hand (ANY of the pulleys!) with the belt on, the belt tensioner may be dead. Do you have the early style manual-adjustment tensioner?

Check if the fluid leaking is SLS hydraulic fluid, or power steering fluid. If it's SLS fluid, the front radial seal of the tandem pump may be leaking. If it's PS fluid, more likely some of the hoses (not the pump itself).

The engine running rough is probably not related.

 

[dinbirb]

If you can turn the pulley by hand (ANY of the pulleys!) with the belt on, the belt tensioner may be dead. Do you have the early style manual-adjustment tensioner?

Check if the fluid leaking is SLS hydraulic fluid, or power steering fluid. If it's SLS fluid, the front radial seal of the tandem pump may be leaking. If it's PS fluid, more likely some of the hoses (not the pump itself).

The engine running rough is probably not related.

Thanks for the reply. The belt tensioner looks like the manual-adjustment type.


The SLS reservoir is full, nothing is missing there.

 

[dinbirb]

I started the car today and it idled fine at first. But as soon as I turned the steering wheel while stationary, the RPMs started surging up and down. This only happens when I’m actually steering.

 

[gsxr]

Have you checked the belt tension?

 

[dinbirb]

Have you checked the belt tension?

Yes i have it is alright

 

[gsxr]

Can you still spin the pump pulley by hand with the belt attached and tensioned normally?

 

[dinbirb]

Can you still spin the pump pulley by hand with the belt attached and tensioned normally?

yes i can still spin it
what are the signs of a broken pump?

 

[gsxr]

You should not be able to turn the pump pulley with your fingers. If so, the belt tension is too loose.