When Cold, in "P" or "N" it smokes, when in "D" it stops...

[impalator]

Hi everybody,

This is more an observation rather than a question... but if anybody has an explanation, it would still find it interesting to know why this is.

The title of this post explains it pretty head on:

When it is cold and I fire my "Lil' Stinker" Bus up, there is a lot of blue/gray smoke coming from the exhaust. Since my ECU malfunctioned and caused me to burn through 3 sets of glow-plugs real quick, CVI bypassed the ECU and I now engage my glow-plugs manually (with Ignition on I mentally count slowly from 1 to 5 or 7 while pushing the "Glow-Button" - depending on how cold it is) and then turn the key to start cranking.

The Van always starts up fine - but with a lot of smoke (and if I say with a lot of smoke I mean it)...

Interestingly, the other day I put it into "D" right after it started and had the brake applied - and miraculously - the smoking almost immediately stopped (it went from "Lots of smoke" to "just a bit of smoke" immediately, and after about 15 seconds it was to "hardly any smoke")....

Now does that make sense? It's gotta have to do something with the Turbo under sudden load (i.e. in Drive) or so... but I don't understand it...

Anyway... just wanted to tell my little smoke story...

Cheers,
Chris

[Chewy]

my guess would be the thrust bushing/bearing in your turbo. It acts the same way the seal bearing on a boat prop does, holding fluid in and out, while also serving as an axel bearing. When they don't seal completely, a little bit of oil and or water tends to seep past when the center shaft is spinning when there is no load. Your description would certainly give you that effect, it doesn't really hurt anything I've seen, aside from oil/water consumption of course.

Edit: Either that or it could be valve stem seals? Though I've never really dealt with that personally, so maybe another member could shed some light on that aspect.

[Meanman]

valve stem seals typically will show the symptom of a cloud of blue smoke on initial start up . In extreme cases will cause blue smoke during running, but will not go away under load as described.....usually accompanied by noticeable oil consumption....in the neighbourhod of 1 litre or more per 1000kms.

Hope that eliminates that as a possibility

[EricN]

Try disconnecting the vacuum supply to the egr valve, see if it changes anything. EGR vacuum is controlled by the ecu.