Technical 2004 Ducato 2.3 JTD, lots of light grey smoke but only when fully hot.

[Hutchweb]

Symptoms only when engine fully hot, 9 o'clock on the temp dial.
Driving and acceleration is fine.
When it is hot coming off motorway and stopping at lights. Light grey smoke billowing out, then smoking badly with light grey smoke when accelerating away.
Like a switch has been flicked, it will then be very smokey.
Stop for 10 seconds and as it pulls away clouds of pale grey smoke which then stops after a few accelerations (it is now getting worse and smoking most of time if it is hot)
So it is like the fuel flow is not switching off.
Engine breathing checked
Injectors checked and one replaced
Valve seals changed
Block pressure checked
2 bottles of turbo cleaner put through the turbo
Turbo oil leak checked, but I don't know how.
Air and fuel filters just changed, have now had the problem for a couple of years, doesn't seem to be using oil or water.
There does not appear to be an EGR, I don’t think it has the wax cold start advance that can sometimes stick.
Engine has only done 53000 miles, 2.3JTD 2004, Fiat Ducato.
At a loss where to go with this now, anyone any ideas?

 

[Communicator]

Symptoms only when engine fully hot, 9 o'clock on the temp dial.
Driving and acceleration is fine.
When it is hot coming off motorway and stopping at lights. Light grey smoke billowing out, then smoking badly with light grey smoke when accelerating away.
Like a switch has been flicked, it will then be very smokey.
Stop for 10 seconds and as it pulls away clouds of pale grey smoke which then stops after a few accelerations (it is now getting worse and smoking most of time if it is hot)
So it is like the fuel flow is not switching off.
Engine breathing checked
Injectors checked and one replaced
Valve seals changed
Block pressure checked
2 bottles of turbo cleaner put through the turbo
Turbo oil leak checked, but I don't know how.
Air and fuel filters just changed, have now had the problem for a couple of years, doesn't seem to be using oil or water.
There does not appear to be an EGR, I don’t think it has the wax cold start advance that can sometimes stick.
Engine has only done 53000 miles, 2.3JTD 2004, Fiat Ducato.
At a loss where to go with this now, anyone any ideas?

@Hutchweb ,

Welcome to the forum,

I note that the you posted the same query on the Motorhome Fun forum on 23rd July. On that forum you received sound advice as to the causes of different coloured smoke.

Partially burnt fuel is exhibited by black smoke. Given adequate air supply a diesel engine responds to the amount of fuel injected. If the amount injected was not being reduced, the engine would run out of control.

We have all seen vehicles emitting bluish grey smoke when partially burning lubricating oil. It also has a distinctive smell, which is very apparent to a following driver.

I have the following hypothesis to offer.

In an idling engine the pressure in the compresser side of the turbo unit will be at a minimum, possibly even partial vacuum due to pressure loss across the air filter. Hopefully the oil pressure will be maintained. This creates maximum pressure across the oil seal, so it may possible for a small quantity of oil to be drawn into the compressor via a failing oil seal. When the vehicle accelerates, this oil will enter the cylinders, and be emitted as blue/grey smoke. With the turbo unit rotating at high speed any pressure difference will be reduced, and the smoke will eventually disappear.

It does not take much oil to make a lot of smoke.

You may need to consult a turbo specialist, who may either agree with, or dismiss my suggestion.

On both the 2.3jtd, and the 2.8jtd EGR was optional.
The wax stat mentioned was used to advance the injection when cold starting on mechanically controlled engines which were phased out with the introduction of the electronically controlled common rail engines. The ECU on a common rail engine performs the advance of the injection when cold starting, in relation to engine temperature.

 

[Hutchweb]

Hi, yes I did post in the motorhome fun forum. Thanks very much for your info around the turbo seals. I think that was one of the suggestions made by Rayners in Newbury (the local experts) and I think that was checked, but I don't understand how it could have been checked without removing the turbo, and I don't think that was done. I'll discuss this with the mechanics I know who have been involved.

@Hutchweb ,

Welcome to the forum,

I note that the you posted the same query on the Motorhome Fun forum on 23rd July. On that forum you received sound advice as to the causes of different coloured smoke.

Partially burnt fuel is exhibited by black smoke. Given adequate air supply a diesel engine responds to the amount of fuel injected. If the amount injected was not being reduced, the engine would run out of control.

We have all seen vehicles emitting bluish grey smoke when partially burning lubricating oil. It also has a distinctive smell, which is very apparent to a following driver.

I have the following hypothesis to offer.

In an idling engine the pressure in the compresser side of the turbo unit will be at a minimum, possibly even partial vacuum due to pressure loss across the air filter. Hopefully the oil pressure will be maintained. This creates maximum pressure across the oil seal, so it may possible for a small quantity of oil to be drawn into the compressor via a failing oil seal. When the vehicle accelerates, this oil will enter the cylinders, and be emitted as blue/grey smoke. With the turbo unit rotating at high speed any pressure difference will be reduced, and the smoke will eventually disappear.

It does not take much oil to make a lot of smoke.

You may need to consult a turbo specialist, who may either agree with, or dismiss my suggestion.

On both the 2.3jtd, and the 2.8jtd EGR was optional.
The wax stat mentioned was used to advance the injection when cold starting on mechanically controlled engines which were phased out with the introduction of the electronically controlled common rail engines. The ECU on a common rail engine performs the advance of the injection when cold starting, in relation to engine temperature.

Hi, yes I did post in the motorhome fun forum. Thanks very much for your info around the turbo seals. I think that was one of the suggestions made by Rayners in Newbury (the local experts) and I think that was checked, but I don't understand how it could have been checked without removing the turbo, and I don't think that was done. I'll discuss this with the mechanics I know who have been involved.

 

[Hutchweb]

I have just bought, downloaded and installed the FIAT DUCATO 2 (2002-2006) (MULTILANG) manual. It is in a weird pc format but I have downloaded the emissions fault finding and turbo replacement and component identifier parts as pdf's. I will try and upload them to the ducato downloads section of the forum for others to make use of.
There is quite a lot under fault finding/emissions and "white exhaust fumes" and I think the only outstanding one in my case is turbo seals. So that is what I'll be discussing next with my mechanics.

 

[Hutchweb]

Have finally had a new turbo fitted and this has sorted the problem out at last. It is such a pleasure to be driving again without kicking out smoke. Many thanks to Matt at Weston motors in Newbury for sorting things.