Poor idle when cold, okay when warm

[LucyLeBingo]

Hello, 1.6hdi gurus's.

My '06 M59 1.6 HDi runs rough as a bears backside when cold, but after running it at 2000 rpm for the length of a song (say, 3/4 minutes it settles down and runs fine.

I suspected the 7 year old glow plugs, renewed, no fault found.
The glow plug relay, renewed, no fault found.

No codes, no EML, just blue smoke on start up.

It's 19 years old with only 75k on the clock and only does short trips these days, could the cold start running issue be caused by coked up inlet valves that all direct injection engines suffer from if only used for short trips?

Any other suggestions to consider? Like is there an ECU trigger point for activating the glow plug relay, because I've rarely seen the glow plug lamp lit in 9 years of ownership.
Is there a circuit I can jack into to have manual control over the glow plug operation, without blowing the CANBUS's mind?

Is there a known good specialist for walnut blasting in the West Midlands?
Or better still a mobile walnut blaster?
Anyone done their own walnut blasting or other intake valve cleaning on this engine.

Any input welcome.

[brodfather11]

On the early Berlingo models (IRC correctly) there was a wax operated cable that when  warmed up operated the advance and retard on the high pressure /injection pump. When cold it helped the starting and as it warmed up gradually returned to normal running position, without it the engine ran very rough until it warmed up in 3/4 mins.

It was operated by the temperature of the engine coolant and was near the thermostat and the cable went to the pump.

Yours may not have this as some models were electronical controlled.  Cant remember the details though.

Someone else may know better

[LucyLeBingo]

Solved ! Despite showing no engine light or fault codes the fault lay in the EGR valve.
It must have been sticking slightly open from start up and allowing exhaust gas into the chambers which was too much before the engine reached operating temperature.
Looking forward to getting some of my MPG back which was also a symptom, more fuel being used.