300 Tdi blue/white/grey smoke on start only when stone cold

Quote:

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Originally Posted by Vern

... A good diesel is a noisy diesel

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:D

I have a good diesel then! :p

noisy up to about 2-ish thousand revs due to the injector rattle, then smooths a little. in terms of road speed this translates to about 80k/h in the D1.
I find that the cars sweet spot for cruising is about 80-90k/h(maybe 95) just before road noise starts to enter into the equation.
At 110k/h it's bearable, but exhaust drone starts to enter into the mix too.

I'm happy to chug along at about 90-ish k/h depending on the situation.
One thing I'm looking into before the year is out is a VNT turbo, as I prefer low down grunt more so than higher speed power. So hopefully that will remove the turbo from the equation.

* I'm thinking that the timing check is a matter of getting No 1 cylinder at TDC, and checking the location of the injector timing pin .. so not too hard a task(even for me).

* Cyclone will be replaced in the next day or three.

* induction system will be cleaned out (hopefully) in the next few weeks(time allowing).

* Injectors! I reckon my options are:
1/ take car to diesel service place for them to check/clean/fix and even do the timing.
2/. get a new set fit them myself and see how it goes. I then have a spare set(my old ones) that i could get cleaned up and serviced and do that as a service item say every 50-ish thousand klm.

Can't think of other things to check(hence the reason for the query).

Definitely a new battery(again!) for the colder weather coming up. The original new battery(720CCA) had to go into the D2 project car. Starting issue (I'm pretty sure) is related to the piddly old 600CCA battery I had to re use when the new one went into the D2.

Ours used to blow a decent puff of smoke on startup and then settle down and ran fine for 350,000 kms, when we sold it.

basically what I'm getting in the cold.

Today, engine sat for about 15-16 hrs.
Didn't start it cold this morning. was home at 8 last night.
Had some stuff to do.
Morning was cold, but started it at about 2PM.
Cold morning gave way to perfect 22-ish mid morning and arvo. car in the sun.
Engine started in less than a second, basically immediately.
Small puff of black smoke as per usual(1sec or less) and no blue/white/grey smoke at all, as it wasn't cold at the time of it's first start.

So I'm thinking it can't be oil seeping into the cylinders and settling, then burning off at start up.
If oil was seeping, it'd smoke up irrespective of cold or warm ambient(I think).

if timing was out, would it still start so easily from cold after so many hours sitting but with warmish ambient temp?
I didn't even think about it at the time, but do now, I hardly used any preheat time too this arvo.

Just to recap a bit again: first three days after timing belt was done, we still had warm days, nights and mornings.
It's only been since our first really cold day/morning where it dipped to like 10°C or below .. roughly 3 days after the belt was done.

Would I be on the right track thinking injectors here now?

300 Tdi injectors are fairly solid and dependable from memory. I think they may be Bosch made too(if someone could confirm).
How often do you service them, or get them checked and stuff like that?
Car runs pretty fine. Seems to have what I thin is relatively good performance(relatively speaking).
got the disco with a new set of 255/70 16's. So it's slightly over tyred, but not massively so. So performance is fine considering those points.
I'm fairly happy with the IP tweak for fuelling, hopefully the uprated IC will reduce EGT on long hard hills tho. If not I'll back off the fuelling a bit more. EGTs aren't a problem, and manageable as they are tho.

thanks for all help and comments so far. I guess it's more about my curiosity rather than this being a major issue.

I'm thinking tho, next camping trip, I'll have to start the fire and get it smoking up as much as I can before starting up the disco. Then start it up to mask it's smoking up if it's cold out, and shut it down when it stops.
Hopefully it'll help minimise any uncomfortable glaring from everyone in the campground.

Check the timing, it's easy and cheap. I just had my injection pump overhauled and the shop set it up to run smooth and not smoke under load - still had old injectors at the time. Mine did the same thing on start, puff of white grey smoke but not always, also took more than the normal instantaneous fire up once preheated.
Plenty of guides online, but essentially you need the locking pins, one for flywheel and one for pump. Look up from underneath while someone rotates the crank you will see the slot in the flywheel through the bell housing drain hole. Whip the coverplate off the time belt housing, three small bolts, the pin should slide in near the top, if it's 180 degrees out need to unlock the flywheel and rotate it one full turn and relock it from underneath as the pump turns at half the speed. The 3 bolts on the pump allows you to rotate the pully relative to the pump to fine tune it.
It doesn't have to be far off, mine was perhaps 1 - 2 mm from the pin hole and it went from being sluggish but smooth and hardly wanting to make boost, to lively and responsive. It should 'crack' when you blip the throttle from idle. Oh yeah, much faster starts and black smoke only

Rod

Thanks for your input BBD.

Mine runs fine in terms of power and boost.
Feels the same, maybe slightly better than pre timing belt change a few days earlier.

The reason I'm thinking injectors is that: if the ambient is warmish but the engine is stone cold(ie. sitting for many hours on end) apart from the usual puff of black smoke on start up there is no smoke.
the other day the car sat from about 8PM til about 2PM next day(ie. 20ish hrs) started instantly/easily .. no smoke at all(apart from the <1 sec puff of black smoke)
Idled nicely and no grey/blue/white smoke at all.
If on a very cold (ie. 10°C) morning, tho, takes a lot of cranks to start(but battery struggles too tho, as it's old and tired) and that's the only time it smokes up(heaps).
After a min or two of warming up, it stops smoking (basically) completely. You can just see traces, but this is more likely condensation rather than grey smoke(and of course it still smells diesely).

I'd have thought that if the timing were out, then no matter the temperature if it's going to smoke up it will irrespective of temperature.
Hopefully someone will put me straight with that tho(ie. how diesels work and specifically intricacies of a 300 Tdi) .. this is my first diesel that I work on for myself.

Reason I'm thinking injectors is, when stone cold, they don't spray very well so produce smoke once they get to operating temps tho, they work better and so smoke stops.
Other reasoning is that the car has no history. it's easy to judge/see that head was done at some point. Having just done the belt, old one was in close to perfect condition, but obviously done some miles as the teeth were starting to show through the belt strip. Belt not worn at all and a few insignificant puffs of black rubbery stuff that blew out of the timing case easily my mouth.
All gears and pulleys were in very good nik too! So belts were done recently.
No idea on injector history tho.