1.6 hdi white/grey smoke

[johntom]

Hi
I have just bought a 2005 307 1.6 hdi with 70k on the clock. When collected, it started ok from cold however there was white/greyish smoke from the exhaust. When revved hard there was quite a cloud, however it seemed to disappear on the journey home and when revved hard there was nothing visible in the mirror, or to relatives in the car behind?
I have Lexia but didn't have it with me, the temperature only got to 80deg (thermostat stuck open?) and there is a hesitation/judder around 1800 rpm, any thoughts ie turbo, injectors, glow plugs or an air leak before I dive in ?


How do I know if its the turbo, I replaced the turbo on the wife's C4 1.6hdi 110 but that was very noisey, this isn't?

[Peter.N.]

White smoke is usually caused by unburnt fuel pointing to glow plugs or low compression although not normally on an Hdi. I would suggest it was steam unless the weather was warm at the time especially if you are not getting it now. Its unlikely that the temperature would reach 80c if the thermostat was stuck open.

Not a lot of help I know, perhaps someone who knows these sngines will be along shortly.

Peter

[spider]

I'd not worry about 80c on the gauge HDi's are quite thermally efficient so that's not a big concern at all.

White / grey smoke does suggest incomplete combustion to me though, then again unburned fuel = black. Condensation is a possibility but that would not keep happening once it was dried out.

Regarding air leaks, if there's any clear pipe on the feed to the filter (1.4 has something not sure if 1.6 does) I'd do the usual checks on that for air bubbles etc. I don't think the air ingress if its present is bad or it would not start very easily or at all.

[johntom]

Hi
we started it from cold yesterday am and there was some smoke visible, but not the clouds from yesterday. I put my hand on the exhaust and I was left with what looked like some condensation and black oil. There doesn't seem to be much play in the turbo shaft but there is oil in the pipe work to the intercooler and inlet?
Does this and the hesitation around 1800rpm fit in with the turbo seals failing?
Also when I get lexia working again will that rule out injectors etc?

[johntom]

Hi according to the po, the car used oil and failed its mot due to the smoke. They said a garage had done a 'smoke test' and that it wasn't the turbo but something inside the engine?

[spider]

I'm not sure what else could make it smoke if its internal. Ruling out rings and valve seals. EGR maybe but that would likely cause running concerns too if it was jammed.

It would be worth your while taking some time to carefully check and clean all breather hoses (beware of using solvents to clean them as it may run on the vapour from that after!)

[johntom]

I will end up taking it into another garage for diagnosis if I don't pick anything up with Lexia. I would have though rings or valve seals would have produced blue smoke though, this smoke is more grey but there is oil in the exhaust smoke ?

[spider]

That's what I mean, an 'internal' leakage would not be that grey. Only other thing is EGR but I'd expect running concerns.

I wonder if the injector leak off rates are too high but I'd again I think you'd have running / power problems.

[johntom]

I had the car running again today and noticed there seems to be a fair bit of clicking from the black plastic box on the left of the engine? The 2 intercooler pipes go to this unit along with a few electrical connectors, what is the unit for?

[spunkymonkey]

Check carefully for air leaks in the fuel supply or signs of wetness around connections - including any drain plug on the fuel filter. Don't know the HDi, but air in the fuel will cause this and a very small leak may not suck air as you're driving, but may let fuel drain back towards the tank overnight so it gets a good gulp of it in the morning.

One test is fit a piece of clear pipe between your filter and the injection pump and watch it carefully for bubbles on the first start of a day - if you have bubbles to start that disappear after a few minutes then you can be pretty sure there's a small leak somewhere.

[spider]

I think the item you refer to is the EGR control valves, one for the valve one for the butterfly (if it has one)

[johntom]

Thanks, is the clicking normal at tickover ?

[spider]

I don't think they should be clicking enough for you to hear them, ie if its just idling the EGR should be shut anyway.

[RichardW]

If it's the unit above the alternator, then it's not the EGR - it's a divert valve to bypass the intercooler to help heat the exhaust up when regen of the DPF is called for. I don't think it should be clicking at idle - never heard ours do it. If it's smoking all the time then there is something seriously wrong with it.... but if the EML is not on, then a diag session won't show it up. Could well be the exahust side seals on the turbo leaking oil into the exhahust.

[johntom]

Yes I suspect the seals, how do I confirm without taking a chance and buying another turbo ?