Black smoke on starting

My 300tdi was run off the highway for much of its life (Airport, airside).
I suspect it was run on red for most of that. I drained the tank and changed filters etc last summer, but it still gives a mighty impressive puff the magic dragon waft of black smoke on starting.
It has been run on white road diesel ever since I put it back on the road, before you ask!
My questions are;
Is this pretty normal for an old 300tdi?
Does anyone know who to contact for a declaration form-DVLA or HMRC? the GOV UK site sent me to sleep.
Cheers,
Jim.

Tdi's do that. On start up the injector pump pushes through a huge amount of fuel to aid cold starting as long as the smoke clears quickly then it's fine. Running on red diesel won't make a vehicle more smokey or anything it's exactly the same as white diesel but with a red dye in it.
I wouldn't bother contacting anyone. After 3 or 4 tank fulls of white you would have cleared out the traces of red diesel.
You could keep your receipts of every full up should you ever get pulled over and proof of its history being run off the road on red for complete peace of mind.
But if you've been running white since last summer I'd imagine they wouldn't be able to trace any red in the fuel system. In fact I'm pretty sure they wouldn't.

+1 On all the above.

When I first got my 200 tdi the black smoke on start up frighten me also. It's normal. As long as it clears up once the engine has turned a few times. I was in the car park when some woman was pushing a kid in a push chair pass my Defender when I started it up. The kid nearly ended up with a black face. You will get used to it and watch before you turn your engine over.

Haha! When I was about 8 my uncle said 'look down there' meaning the exhaust of his FZR600. He then opened it up leaving me looking like id had a hard day down the pit.

with apologies to @109inches for the cut and paste - here's my opinion....

Tdi's do that. quite a few do, agreed

On start up the injector pump pushes through a huge amount of fuel to aid cold starting as long as the smoke clears quickly then it's fine. Running on red diesel won't make a vehicle more smokey or anything it's exactly the same as white diesel but with a red dye in it.

I'm not sure I agree that red and white are the same fuel - we are told by our supplier that the red (Gas Oil) we buy has a lower cetane number than the white (Derv) - I.E. they are not the same fuel - the calorific value of Gas is lower. To get round the smoking diesels running on same, our supplier recommended a cetane booster, which does what it says on the tin = no more smoke.

I wouldn't bother contacting anyone. After 3 or 4 tank fulls of white you would have cleared out the traces of red diesel. Agreed

You could keep your receipts of every full up should you ever get pulled over and proof of its history being run off the road on red for complete peace of mind. This too
But if you've been running white since last summer I'd imagine they wouldn't be able to trace any red in the fuel system. In fact I'm pretty sure they wouldn't. I would imagine the history of the vehicle will be self explanatory in such circumstances, and seriously doubt they would detect anything more than a very, very tiny amount of red..

If the smoke is excessive - you might like to check the boost pin for corrosion / sticking. - and the diaphragm for condition too... possibly even, subject to mileage get re-con injectors.

I read a while back that cetane and sulphur differences were brought in line with white diesel to meet emissions.

But red diesel will not make a vehicle smoke more than white diesel. Especially in old Diesel engines like the tdi's

Totally off topic - have you got a Fintail? and did that 6 cylinder unseize? BTW - I agree with previous posts, doubt there's any dye left in your tank/system - and of course you've changed your fuel filters? [I only mention it because if they're being really arsey they test them as well]

I'll always remember my little lad wanting to come to the shop in my truck, and in excitement running around the passenger side near my side exit exhaust as I started my truck up... He wasn't too impressed...

My 200tdi doesn't pump black smoke on startup, I start mine in the garage and drive out so I would notice if it did

???

109inches said:

But red diesel will not make a vehicle smoke more than white diesel. Especially in old Diesel engines like the tdi's

Click to expand...

Sorry, but that is not born out by our experience here. most notably a 1994 3Ltr Nissan 4 pot industrial engine, which smoked like a trooper before the cetane booster was put in its gas oil, and a 2004 Perkins 1004T, which was almost as bad.
We thought the Nissan was knackered - 14000 hours, so its shouldn't be, but when we checked compressions and had the lube oil analysed - it was all good, and this is what raised the question of fuel - added the cetane booster, and the problem has gone away.

Some TDi's do smoke on startup, but I still think the OP should be checking the boost pin...