Smokey on startup

[amacman]

hi, i spoke with buddy and he just says most likely slightly over fuelling as in injecting a bit too much fuel for the amount of air . so your MAF measures how much air being sucked in , air temp sensor for adding more fuel to help cool engine if incoming air very warm and engine hot , so diagnostic test could tell if those sensors working to correct values . or could be like i previously said that you are losing some quantity of air after sensors thus your fuel to air ratio is incorrect . there are also a multitude of vacuum pipes that are used to actuate stuff , so if one loose or leaking it could cause havock .

[Farvs]

Originally Posted by amacman

hi, i spoke with buddy and he just says most likely slightly over fuelling as in injecting a bit too much fuel for the amount of air . so your MAF measures how much air being sucked in , air temp sensor for adding more fuel to help cool engine if incoming air very warm and engine hot , so diagnostic test could tell if those sensors working to correct values . or could be like i previously said that you are losing some quantity of air after sensors thus your fuel to air ratio is incorrect . there are also a multitude of vacuum pipes that are used to actuate stuff , so if one loose or leaking it could cause havock .

Thanks for taking the time to look into this. The car has been extensively checked with diagnostics - i'll mention the pipe idea when I drop it off tomorrow.

[amacman]

if you use biodiesel then organisms will grow in fuel system , not being able to actually see your problem means all this guessing when there may be nothing wrong with it . anyhoo good luck .

[Farvs]

So the MAF was changed and guess what..... still smoking . I really hoped this would solve the problem. Had a good long chat with the garage this morning and they are pretty stumped and don't really have any ideas as to what else could be the problem. I mentioned the vacuum pipes but was told the diagnostic tests they have carried out would almost certainly have picked these up and the information is all fed back to the ECU eventually and this would produce a fault code.

Given that this all started with faulty injectors I'm weighing up the option of having the injectors that were fitted 10 months ago removed so they can be bench tested. Downside is having to spend more money and only a slim chance these are the cause.

I'm currently wishing someone would just steal the bloody thing so i can stop bleeding cash

[Keksus]

I have the same thing on my `04 with the same engine. Little bit smoke after starting the engine. Well, I am quite sure that the fault is the glow plugs. Then the engine stars on, they dont get hot enaugh so all the diesel in the cilynder does not work out and spits it out through the exhaust. In the diagnostics it is to see how the plugs are working, so it`s easy to check.

I am getting to change them soon. 6 of them cost round 80-100eur. Changing is more complicate than in gasoline engines, so it is better not done by yourself.

[Farvs]

The glow plugs have been checked and are all fine. I was hoping that would be the cause as they are relatively cheap to change.

[vinuneuro]

Is the smoke fuel or oil? If it's oil, it's the valve stem seals.

[amacman]

if the smoke is only on startup then leave it alone , so is the car otherwise running normally ?

[Farvs]

Originally Posted by vinuneuro

Is the smoke fuel or oil? If it's oil, it's the valve stem seals.

I've been told its fuel not oil so rules out the valve stem seals. Apparently, if it is this, it's a pretty major job.

[Farvs]

Originally Posted by amacman

if the smoke is only on startup then leave it alone , so is the car otherwise running normally ?

With all the work done to the car it runs like a dream. I wish I could ignore it but is looks terrible - something you'd expect from a 20 year old banger, not an X5.