Wrong power steering pump belt?

Hello!

What happens if the power steering pump on e9x m turns the wrong way? According to realoem there are 2 pumps with different codes.

Car came out of the factory july 12th 2008.

When at 4-5k rpm and turning the wheel whine gets stronger and seems like the sound comes from ps pump.
I know its hard to find the faulty pulley because when putting more tension on the belt via turning the steering the faulty pulley noise also becomes stronger, whether or not it is the ps pump but im 80% sure its ps pump sound.
Almost all pulleys and tensioners changed (have not changed ac, ps, water pump)

Recently found out from the interwebs that the one sided belt has off-centered idler pulley (nr 5) if im correct?
As my car is after the 05/15/2008 when they changed to double sided belt mine should have centered idler pulley and double sided belt.

On my car there is one sided belt and centered idler pulley. The routing for it is also for the one sided belt.

Is it possible that some previous owners mechanic put the wrong belt on or the wrong idler pulley?
I changed the pulley to the same one that was on the car but did not check the production dates - it was shot anyways.

Can hydraulic pumps even work the wrong way?

If i put the double sided belt on for testing is there possibility i brake the ps pump completely?

The pump won’t work if it’s spun the wrong way.

The oil filter housing is also different, to accommodate the change in idler pulley design. I’m sure your car was built with the parts you see currently- nobody would have changed all that out. You probably just have a bad pump- that’s not uncommon. Though it does create a problem as you can’t find the old pumps anymore. And you’re forced to update the pump, idler, belt, oil filter housing.

I’ve seen quite a few late 08, and some early 09 mfg cars with the old style system. Yours isn’t really an anomaly. Advertised cutoff dates aren’t always a guarantee when it comes to supercessions- you still need to put eyes on the parts to confirm what you have.

deansbimmer wrote

The pump won’t work if it’s spun the wrong way.

The oil filter housing is also different, to accommodate the change in idler pulley design. I’m sure your car was built with the parts you see currently- nobody would have changed all that out. You probably just have a bad pump- that’s not uncommon. Though it does create a problem as you can’t find the old pumps anymore. And you’re forced to update the pump, idler, belt, oil filter housing.

I’ve seen quite a few late 08, and some early 09 mfg cars with the old style system. Yours isn’t really an anomaly. Advertised cutoff dates aren’t always a guarantee when it comes to supercessions- you still need to put eyes on the parts to confirm what you have.

Thanks for help!

Dug deeper on this topic and found out that in the steering rack there is check valve banjo bolt that is designed to protect the ps pump - probably to prevent the ps to turn the wrong way when turning car off etc.

Indeed, it is really hard to find the used old ps pumps, even the newer design ones actually in Europe.

Original from BWM in Europe is 1100€, BOSCH used to make the old design one for 350€ but not in stock anywhere. Only one chinesium pump.

As the car is on lift anyway, waiting for throttle actuators, im going to open up the pump and see whats going on there.

I just ordered and bought new P/S pump 575 EUR, older type p/n 32412283041 just for spare. Planning keep my car for longer time and plan to buy several spare parts as prices go up and production may be discontinued.
Ordered steering rack also, old rack has some clunk when drive slowly bad tarmac condition road. Will see if this order success, ordered with old part number but ther now new P/N and availability N/A atm.
32102283633 -> 32102475185