Power steering issue diagnosis- pump failure most likely, which brand pump to buy

[Dino D]

Sooo car back on the road after 6 mths and dealing with coolant hoses and the aftermarket vacuum hoses for the M50 manifold collapsing.

mucky day but reminded me why I love it and put up with the never ending ‘tinkering’ (character / unreliability / general pain in the @**)!

so 60 great miles and then the PS made a ‘grumbly’ sound and vibrated the wheel.
Then steering becomes heavy as in no PS assistance.

ive had a cursory glance and so far:
Belts all in place
No PS fluid leaking (need to check reservoir)
No funny smells or noises.
The cooling loop felt cold?

i should add that last year (and about 500miles) ago I preventatively changed out the low and high pressure hoses with an aftermarket set (great quality).
Also changed the reservoir with a Febi item.
I asked the mechanic who did it to send the rack away for a refurb- he refused saying the rack was perfect and to leave it alone.

after the pipes were changed the steering developed a ‘grumble’ and vibration - mechanic said he’s seen this on e46 and believed it was something to do with the BMW high pressure pipe material that damped noise/ vibrations.
He did not suspect the pump or rack and advised putting a BMW item on.
we did and the noise disappeared, until today!

what do we think - pump / rack?
Cooling loop was not hot but I’d driven 20 miles back home without PS so sign no fluid flowing?

how do I diagnose what is wrong?
Oh and I have a track day booked on 11th April

 

[Dino D]

It’s lucky it looks good, sounds glorious and is naughty on greasy roads or it would have been left at the CoPart in Sandwich (incidentally it was on the dual carriageway there that the PS packed up!)

 

[the Nefyn cat]

My one made some horrible sounds a while back, turned out to be the UJs on the steering column seizing.

 

[Dino D]

had a look underneath-fluid all over the place but seems to have comeout of the pump itself?

reading up this a failure mode of pumps - seals blow.

this one has down 140k miles.

when turning lock to lock there is no sound at all from the pump indicating it is dead?

Sooo looking at pumps - reading up on e36 forums it appears that the cheaper pumps are variable quality. I think I remember reading on here @GazHyde going through similar on his Z4M and finally settling on a BMW supplied item?

Can’t find a UK BMW dealer price online but on the mains land they seem to go for £300ish

autodoc has these

Needs to research these manufacturers as sometimes they had ‘German’ names but it’s rubbish made on China. Even Febi doesn’t mean much these days.

 

[Dino D]

My one made some horrible sounds a while back, turned out to be the UJs on the steering column seizing.

Unfortunately not my issue. Steering is now quiet but heavy.

 

[GazHyde]

settling on a BMW supplied item?

I ended up with an aftermarket one from Autodoc.

 

[Dino D]

Update

This is a record for me - 50 miles between flatbed journeys…
It’s done less than 1k miles since last year and at least 300 of them on the back of a flat bed…gets amazing MPG when being carried though and looks pretty.
Beginning to think it’s protesting against being driven on these rubbish Kent roads and prefers being carried round like royalty.

The garage has had it apart and the o ring on the high pressure pipe has split - hopefully just a fresh o ring and it’ll be ok, part arriving from BMW tomorrow.

I did drive it 20 miles back home after the o ring popped, hopefully the pump is ok still..

@Lee did your pump survive after the PS oil slick slip and slide fun at Brands?

 

[Lee]

Alright mate, yeah the pump was fine after that episode on track. As you know the pump line blew on the corner emptying the system. After that session I drove home 50 miles with no power steering and later that week replacing the line and topping the system up all was well. The pump is still on the car to this day.

 

[Dino D]

Update - it wasn’t just the o ring - the actual pipe has cracked:

It’s a year old genuine BMW item and the car has done less than 1k miles, and no track days.

unlucky? damaged before it got fitted?
And think this was done as ‘preventative’ maintenance to prevent this exact issue happening on track

 

[Lee]

With the higher RPM and engine setup you have I’m not surprised.

 

[Dino D]

I’m going to get that underdrive pulley set up but it’s from Turner in the US so never be here in time for next weeks track evening

sounds like a good mod for engine pick up.

I’ll short shift until it’s done (@spurs fan in a coupe - that a my official excuse - doctors orders!)

I wonder if the S50/S54 engines use a different set up given their rev range?
But anything M will probably be mega taxed ££

 

[Lee]

It’s a better way forward. Pretty sure I just bought a single very slightly larger pulley so it didn’t spin as fast.