Engine: D5: Lumpy at idle when cold

[Bashy]

Hi folks, the engine appears lumpy at idle when cold, almost as if its only firing on 4.5 cylinders, it appears to be better with a little gas though, i also have to give it some gas as i turn the key else it will struggle to start. My initial thoughts was injector but i do not feel any issues when driving, well, not related to this anyway Any thoughts please?

[simonwedge]

Injectors are most likely cause I think, do a leak down test as here: https://www.youtube.com/watch?v=bbQhKjj6jis and see what the result is

[dingov70]

Morning , my first port of call would be to make sure ALL the glow plugs are working / getting power .

Becoming difficult to start as the temp drops is always a good indicator of deteriorating glow plugs , they work ! but not properly and most modern diesel use post heating to ensure cleaner running until the engine is warmed up . Post heating is reduced voltage to the plugs for a few minutes and normally dependant on coolant temperature

This leads to longer cranking of the engine & lumpy tickover when cold that goes away as the engine gets hotter

[The Landshark]

It'd be worth taking a look at the egr valve too

[gumboots]

2nd for the EGR. I just had the same symptom - like a 4/4.5 cylinder on 2006 Euro4 V70 2,4D. The EGR and cooler were removed today. The vacuum assisted EGR valve had a leaky suction actuator (causing loud popping at the filler cap) and the central butterfly was jammed solid. The main EGR valve was also very gunged up and the actuator motor was very stiff to move. Replaced with a 2nd user part and cleaned everything else out, 100% better now.

[Bashy]

Thanks folks, that leak test looks very involved for someone that could just about manage a plug change, having said that, i did remove an EGR many moons ago, not on a volvo though, probably one of my Lagunas.

Glow plugs i can do though, im sure i have deffo done them before, then again, not on a Volvo.

Something i did notice the other day though, poss coincidence but...

A few seconds after start i put it in neutral (cant remember why now) and the lumpy idle was gone, back in to park and still gone, normally it lasts a few minutes im sure....