Disco td5 weird ACE issue.

Had the disco on the road for the first time in over a week today. Was a long journey and towing trailer and we'll into journey started to noticed some noise/ vibration on cornering. Quick look see and when I first stopped noticed that faint drone at idle that accompanies my ACE was gone and on increasing idle some strange noises heard from valve block. There were no warning lights and I know they work as I had problems with system in the past. What was also very noticeable, being on windy country roads was that the car was wallowing all over the place. Has anyone ever experienced something like this.....and btw please avoid suggesting removing ACE system as I now know what it's like to drive a disco without it....bloody horrible.

odd one , are the drop links all still connected, do lights show when ignitions first on

jamesmartin said:

odd one , are the drop links all still connected, do lights show when ignitions first on

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I haven't checked drop links yet, need to have a good look as it was late when I got back. I'm thinking pump or valve block though as I can no longer hear the faint drone of the high pressure oil when engine is running. I will check warning lights today too. Pump was replaced with new 5 years ago after all pipes replaced. The system is making a loud droning on cornering but it's not effective, as tho the pump is struggling. I think I will remove filter and check today as well.

Bit of investigation tonight and not any further on.
Warning light comes on with ignition.
Valve block filter checked and found clean.
Both Arbs and linkages all good and tight.
Auxiliary belt removed and pump checked found free and smooth to turn. I've left visc fan etc off so I can run engine in morning and get a good look at everything.
May end up going to local garage and getting on diagnostics to check operating parameters, I'm have a feeling pressure is low

As you describe it the system is in "floppy" default but that should bring the warning on and store a fault code, if no codes stored and the behaviour is still erratic IMO you should try a known good ECU cos they can missbehave that way... no worries cos due to the de-ACE hysteria the market is full with cheap good ones, no programming needed it's plug and play, but if you have access to diagnostics it's good to run a accelerometer calibration on it

BTW did you replace any pipes before that symptom?, cos then we have the explanation

sierrafery said:

As you describe it the system is in "floppy" default but that should bring the warning on and store a fault code, if no codes stored and the behaviour is still erratic IMO you should try a known good ECU cos they can missbehave that way... no worries cos due to the de-ACE hysteria the market is full with cheap good ones, no programming needed it's plug and play, but if you have access to diagnostics it's good to run a accelerometer calibration on it

BTW did you replace any pipes before that symptom?, cos then we have the explanation

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Sounds like a good way to go. The full set of pipes were replaced about 5 years ago and the pump soon after but no recent maintenance at all. System had been working fine up until this hiccup. It makes sense that ecu could be at fault. I suppose if I get it on diagnostics then I should know right away if system is working or if it's capoot. There's no "drone" from the system any more and when increasing rpm you can here a fluttering noise that sounds like a leaking exhaust manifold but it's definitely coming from ace valve block. I know a place with full diagnostics who will check for 20 quid so I will go that road and post findings.

Replacement ECU fitted today and no difference. Bugger!
Diagnostics next to check system pressure. I'm not worried about accelerometers too much as the system is even different with vehicle at standstill and idle running, no high pressure " noise" more like clicking.
Anyone ever heard of a pressure transducer failing in healthy condition?

It seems that you approached it the other way around, you should have put it on prop[er diagnostic before you replace the ECU, cos the gist of my statement was : "if no codes stored and the behaviour is still erratic IMO you should try a known good ECU" cos a faulty transducer would throw a fault code so would low system pressure and in this case the default would be "locked bars" not "floppy"