Renault Clio 1.5Dci problems

Mum has a 2006 Clio 1.5dci, been having a few issues, for a few months when driving it takes a while to accelerate, if you push it hard it will get there albeit with a cloud of brown/black smoke and then the electronic fault light on the dash will come on.
I have cleaned the egr valve which was coked up, and can’t see any damaged wiring in the engine bay, only thing I can see is a chafed hose from the boost solenoid.

It wouldn’t start the other day so she got the AA out and he got it to start after disconnecting and reconnecting the battery and found the following fault codes. Patrol found the following fault code/s:System : Engine control 1 - 52X / Diesel CR/EDC DCM 1.2P0380 - Heater plug monitor. Error Message : Fault. Status 2263 - Boost pressure control. Error Message : Control limit maximum value reached. Error sporadic. Status 0235 - Boost pressure sensor. Error Message : Control limit minimum value reached. Error sporadic. Status 0685 - Main relay. Error Message : Limit exceeded. Error sporadic. Status 0045 - Boost pressure control. Error Message : Open circuit/ground short. Error sporadic. Status 0231 - Fuel metering unit. Error Message : Open circuit/ground short. Error sporadic.Non startEngine Oil Level Ok. Coolant Level Ok. Loss of fuel pressure . Started after battery reset.

Now one thing that is odd is that even when the ignition is off, I can hear a relay ticking from the fuse box in the engine bay, and the same ticking from the egr valve- this stops when it is unplugged. You can’t stop the ticking unless you disconnect the battery- it will just drain it as it’s pulling around 2A. Clearing the fault codes doesn’t stop it.
This ticking issue has only started since it broke down the other day, it hasn’t been present since the main acceleration issue.
Any one got any ideas?

It can be a multitude of things, unfortunately the ECU shows so many fault codes you cannot rely on it to carry out the diagnosis.

Have you found the relay that's ticking?

Is it a MK2 phase 2 or a mark 3 Clio? The age of the vehicle is right on the switch over.

The MK2 phase 2 had problems with the main earth strap corroding, check this.

It’s a mk3, I haven’t looked for the clicking relay yet. Next time I’m over I’ll check

Looking at the number of faults and the clicking relay I suspect there maybe a corrosion of wiring somewhere.

I'm not clues up on the mk3, but I know the MK2 had all sorts of ingress issues, might be worth scouting the Renault forums

Had a go tonight, turns out that Relay No. 2 is faulty and seemed to be stuck on making a ticking noise and draining the battery, I swapped it for Relay no.1 (heated rear window) and the fault has gone. So it’s back to ‘normal’ now, albeit with a non functioning heated rear windscreen.
Still seems to not be boosting, I’m suspecting the boost control solenoid now as when I wiggled it after running it was making a buzzing sound and this dissipated.

Got a new boost solenoid off eBay and this has fixed it, no more smoke or fault codes and it drives nice and smooth like normal and it’s got its power back. Glow plug code still remains but I’ll have to test/replace the plugs as it isn’t starting quite as quick as I’d like but other than that I’m happy