E46 325ci whining noise

[LLC24]

Hello all. So, I recently bought a 325ci with 136k on the clock. There is a whining noise that can be best heard while in the cabin and more noticeable at lowers speeds. Using the clutch and changing gear does not affect the noise in any way so I’ve ruled those out. Applying pressure to the steering wheel at a standstill however does make it stop/ decrease. The aux belt doesn’t seem to be loose or damaged at all. Any ideas what this could be?
On a side note, the car struggles to start sometimes and I have to rev it a little upon starting to get it going, however this may be unrelated as my faulty air mass sensor is unplugged for the moment while I'm waiting for a new one. Once turned on the car engine runs nicely.

[naturalaspiration]

Steering fluid level ok and the fluid itself is not brown?

[Mave]

Maybe similar, my 2004 330i makes a humming sound which goes up and down with steering effort at low speeds. Its done it all the time I've owned the car (~40K miles) with no apparent ill effects. (Fluid is clean and full, and I've changed it in the time I've owned the car).

[LLC24]

naturalaspiration said:

Steering fluid level ok and the fluid itself is not brown?

May sound a bit stupid but I don’t know here in the engine bay I would check it?

[LLC24]

Mave said:

Maybe similar, my 2004 330i makes a humming sound which goes up and down with steering effort at low speeds. Its done it all the time I've owned the car (~40K miles) with no apparent ill effects. (Fluid is clean and full, and I've changed it in the time I've owned the car).

Yeah I guess it’s kind of like a humming noise, hopefully it’s not anything then but will be getting it looked at soon just in case

[LLC24]

LLC24 said:

naturalaspiration said:

Steering fluid level ok and the fluid itself is not brown?

May sound a bit stupid but I don’t know here in the engine bay I would check it?

Steering fluid is all good, just checked it

[Triumph Man]

LLC24 said:

On a side note, the car struggles to start sometimes and I have to rev it a little upon starting to get it going

I had that on my 530i and it turned out to be a camshaft position sensor, only seemed to affect it when the engine was warm though.

[Obison]

Whining noise is probably the bearing in the power steering pump, I've had 2 fail over the years.
And the starting problem will be either crank or cam sensors, very common problem.

[LLC24]

Obison said:

Whining noise is probably the bearing in the power steering pump, I've had 2 fail over the years.
And the starting problem will be either crank or cam sensors, very common problem.

I’ll mention that to my mechanic when he looks at it then and see what he finds. Would those sensors come up on diagnostics? As I’ve had it done and the only thing that came up was the air mass sensor

[Touring442]

PAS pumps were a bit iffy on there - the LF20 (rounded domes rear cover) was bad for just shearing internally resulting in an immediate loss of PAS, the LF30 (flat rear cover) was generally fine. But they're old cars now.

[LLC24]

Touring442 said:

PAS pumps were a bit iffy on there - the LF20 (rounded domes rear cover) was bad for just shearing internally resulting in an immediate loss of PAS, the LF30 (flat rear cover) was generally fine. But they're old cars now.

Does it depend on the year? They changed something about the steering in 01 didn’t they? Mines an 02 plate so it’s after that but I’m pretty sure it is something to do with the steering although it seems to work just fine at the moment aside from the noise.

[Obison]

I’ll mention that to my mechanic when he looks at it then and see what he finds. Would those sensors come up on diagnostics? As I’ve had it done and the only thing that came up was the air mass sensor
[/quote]
Mine never did, but i presume they can show faults.
You can get the sensors from GSF, they are cheap and despite everyone saying buy genuine i have never had a problem with them.
Cheers.

[Touring442]

LLC24 said:

Does it depend on the year? They changed something about the steering in 01 didn’t they? Mines an 02 plate so it’s after that but I’m pretty sure it is something to do with the steering although it seems to work just fine at the moment aside from the noise.

It was more dependent of what pumps LuK were supplying that week.