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

TDI's normally have a puff at startup even when warm, its just an enrichment that takes place at start up just like a sort of auto choke.

Thanks for the reply.
I get a very brief puff of black smoke at start. Not enough to appear environmentally vandalous or irresponsible, barely a second or so of a puff, and dissipates quickly.

But the blue/white/grey smoke when cold lasts a while.
Once the car has started from stone cold, I'll let it idle a short while .. 10-20sec or so, then give it a few revs(say 1000-1500) .. a fast idle, or so to speak.
It's at this fast idle that it blows the smoke, and mostly under the initial accelerator load. If I hold it at 1000-1500 steadily, there's really no smoke to speak of.
It's more the accelerator push that produces the smoke/haze/annoyance!
Digital temp gauge only has a readout from 50°C and onwards, but before it registers, and the engine has warmed a little(you can feel it, eg. through warmish air in the heater) the smoke stops(a very small slight puff), no matter how much I rev it too.

I drive to work, I work about 8 hrs, so the car gets cold again when leaving work(but not in the same way as an overnight stone cold start). No smoke so to speak of, as it does from an overnight stone cold start.

When warm, I get the same 1sec or less puff of black smoke at start up, and this doesn't change with temp.
But the white/blue/grey smoke suddenly arrived, more so with the cold weather, than the day or two after I did the timing belt.

I will look into checking the injectors sooner rather than later, as I have no idea on the cars history, other than what I've done in the past year myself.


anyhow, I guess I'm just being paranoid having just done the timing belt(never done one before), and looking for excuses to blame myself for having buggered up something in the process!

The blue smoke will be oil and possibly from worn stem seals.

Originally Posted by loanrangie

The blue smoke will be oil and possibly from worn stem seals.

That's what i was kind'a hoping not to hear.
Probably a build up of oil in the cylinders that just so happens to clear out once the engine warms slightly ... but why only on a cold morning.

apart from possible injector causes, I'm also thinking could the turbo also be causing something like these symptoms as well?

In the next few weeks, when time allows, I'm going to give the intercooler both a clean out(step one) and then(step two) eventually replace the original with an uprated one I got a while back.
I'm hoping that may have a bit to do with it too.

Yes , turbo could be worn .

Check the Cyclone on drivers side rocker cover and hoses, could be blocked or not draining proper, also check if you have oil in the intake manifold and intercooler, you may have excessive blow-by and getting oil through the intake side, Regards Frank.

Originally Posted by AK83

hey folks:
I just did the timing belt on the tdi a few days back.
Weather was warm, has been very warm(20C +) for a while now.

When I did the belt, thinking the crank was locked in place with the (inadequate) locking screw plug thingy, I went to remove the crank pulley and it moved a bit(a degree or 10 )
Lined up the crank again before everything was locked down/tightened up etc, and when all was done prayed(even tho I'm totally agnostic!!), and sure enough it started immediately, no throttle.
Possibly better than before, but that could have been a relative imaginary perception having just done some major work with zero experience of that kind'a work.
IP timing pin was never moved, other than at one point when I retightened the crank it got wedged harder within, moved crank 1/2 degree and it slid out nicely.
Had to undo the 3 bolts to move the IP pulley wheel to fit the belt up on the teeth, and I don't remember it needing much. Belt slipped on fairly easily too.
Cam was wasn't touched other than when fitting the belt, but no force to move it from it's timing mark at all.


.. anyhow.

It's been a long time for us down here since we've had a major cold day/morning and this morning was the first since the last.
I always remember that the tdi did puff out some white/blue/grey smoke in the morning, but it's been so long I can't really remember how much(back then).

This morning tho, it seemed like a lot or too much, with the above caveat that my memory has probably deteriorated since last winter.

I'm probably just paranoid and my memory has failed since last winter when it was last cold too, so I may be over reacting.
In saying that tho, my paranoia is centred around the possibility that I've whacked the timing in some way.

Tdi uses no oil(surprisingly). If any, maybe 500ml lost since the last service less than 10K klms ago.

I have read that the fuel timing could be out, but due to lack of experience with diesels/tdi's .. zero idea on how you'd check such stuff.
And I'm even thinking maybe I should take it to a diesel servicing type place to get it checked, and or injectors cleaned/serviced etc.

So any hints, tips, info and who to use/avoid for diesel services(around Melbourne's north) would be appreciated too.

Thanks,
Arthur.

Does the engine run smoother/quieter since doing the belt?

Re: cyclone.
ordered a few weeks back, finally came(from UK) will fit this coming weekend.

Re: smoothness/quietness.
I'd say smoother for sure, mainly at about the 2-3K range.
Pre doing the timing belt and not knowing the engines history, I rarely revved it past 3K .. maybe once or twice for testing something
It definitely feels smoother coming to 3K rpm, and then feels smoothish to about 3.5K, where I continued on and revved it to 4K, a few times just to see.
Started to feel a little gruff/rough past that 3.5K rpm range and I'm not a revhead in any way.


Long tedious story:

Pulled the intercooler hoses when I did the timing belt. Lower hose as per usual for down there is covered in greasy oily residue from years of not having been cleaned at any point. No oil inside, minimal residual oil film stuck to the silicon hose walls, easy to clean off.
Top IC hose(again silicon .. came with the car, and they look aged) had that off and wiped the residue off the outside. inside it appeared that there was no large oil build up but didn't clean it. It sat for the entire day while I fiddled and went out to get stuff and come back to finish fiddling with the timing belt. From about 10 to about 6, on/off, smoko, etc.
About two small droplets of oil eventually built up inside the top IC hose whilst it sat out in the sun.

I dunno how long it takes for oil to build up in the intake/IC system, but I'd say the silicon hoses could be a few years old now going by their faded colour(blue) and staining, so again history unknown.
So with that in mind, and I've never taken the IC hoses off to check .. inlet manifold had very small amounts of residual oil within. wiped easy with a rag, as far as I could push the rag in.
Rag was a clean healthy old t-shirt, free from lint and stuff, so no contamination inside the manifold.
It came out black of course, but it cleaned up the insides pretty well .. not spotlessly, but more than clean enough.
Have yet to check inside IC itself, but I have a plan to fit an uprated/upsized IC soon when all the parts come together.

What's funny/interesting is the nature of the cold startup.
At home, lets say cold start up could be with the car resting for about 8-10 hrs, sometimes 13. eg. I get home from work at 7, I'm off to work again at 8-9.
Yesterday I got stuck at work for about 14hrs all up. 13hrs work, but I get there early and so on .. so an easy 13hr rest for the engine, closer to 14hrs.
It was a bit cold-ish at about 730PM when I went to start 'er up, lots of condensation, I'd say about 10-12°C.
Car wasn't easy to start, a couple of preheats, and then it needs a bit of throttle to start from cold, this has always been the case, but the battery is a bit past it's use by date.
This is the same routine for a cold start from home too.
BUT!.. the difference is, there's barely any smoke at the work start up, even tho yesterday's was way longer than most from at home.

I'm actually coming around to thinking the car is evil and hates me.
Apart from trying to understand/diagnose what the issue is or could be another reason I'd like to sort the issue is that at home, I generally start the car up and let it warm up for a few minutes while I get the kids ready.
Sometimes I forget, but my son always forgets to close the front door. car is always backed up into the driveway, which of course has the exhaust pointing at the door.
I've actually had a modded tailpipe fitted when I did the exhaust where it points out sidewards and down so it points to one side of the house, and away from feet/legs.
But at the house, if there's no wind smoke is fine going down the side, rather than straight back and inside. But a bit of wind can blow smoke into house sometimes and choke it up for hours on end!
Parking nose first isn't an option too tho.