Noise from ACE?

[CraigH]

Today I took a D2a equipped with ACE for a test drive and on the drive there were a number of round-a-bouts to navigate. When we were cornering you could hear a mild moan in the car not uncommon to a power steering pump noise. I'm guessing its ACE making the noise and not the power steering, is this normal for there to be some noise from the ACE pump?

Cheers, Craig

[Graeme]

From where is the noise originating? The pump can prduce a low frequency moan which is more pronunced in a manual when operating at very low engine revs. If the noise is coming from below the driver's feet then there could be a small pebble lodged between the valve block and the chassis.

[CraigH]

It's sounds as you described a low frequency moan. We were swinging around small roundabouts and that's when you could hear it. It didn't sound bad, just you were aware it was working.
Last one I drove was on a freeway do no real chance to here it working I guess..

[CraigH]

O and it seems to be coming from within the engine bay.

[Road Stone]

Both my Discos have ACE and make no noise, but I have heard of people getting some sort of sound.

Cheers Jerry

[lewy]

Mine makes that noise all the time when cornering.I assume it is normal.you could possibly pull a fuse somewere to confirm.

[Pedro_The_Swift]

both mine have been noiseless,,
having said that,
a lot of pumps were replaced under warranty because of noise.

[simonl8353]

I would suggest its the power steering pump, not the ACE.

[lewy]

Possibly power steering pump,However i replaced my power steering pump 2 weeks ago and the noise is still there.Is the ace system speed reliant ie does the vehicle have to be at a certain speed to activate i thought 40km.If so do you go around roundabouts at more than 40km.

[Graeme]

ACE is active above about 4 kph. ACE pressure resonance is engine speed related.

[antond]

My ACE does make a low noise on cornering - the harder the cornering the more pronounced and is from the ACE valve block. Some have said the mounts (or lack of) can cause this as the block uses PWM oscillation to control pressure and transmits the vibration through the chassis. It does not interfere with the operation though.

[Graeme]

The vibrations are pump pulses which vary with engine revs and are particularly noticible at very low engine revs with high ACE pressure requirements. The pwm frequency of the pressure regulating valve is much higher and constant.