Thread: Help needed with 300tdi smoking issues

Hi Guys I’m new here
…after a bit of advice if that’s ok…..my series 3 has a 300tdi. The motor was fully rebuilt about 10 years ago and has only done about 20,000 km since. Sat around just doing farm duties. When I got it the guy told me to replace the turbo cartridge. The engine has always blown a lot of smoke at all times and this smoke smells extremely strong of diesel…..when I showed it to an old mechanic he said your injectors need replacing. Sure enough i took them out and they were not good so I got a deal on a set of rebuilt ones from the UK so purchased these and put them in. Car runs much smoother but still makes all the smoke. Have checked coolant and no bubbles and no bubbles and no water in oil. Car starts first pop every time and runs smoothly. Let it run for 2 hours just idling and no overheating so I think head gasket fine. Could it be turbo cartridge ? I still have not replaced that… Any other possibilities ? He said injector pump had been fully rebuilt with motor but I have read somewhere that these can be too advanced in setting and provide too much fuel ??????…thanks in advance cheers Simon

Originally Posted by SimonL

And if it comes out black from oil what would be the next course of action ?

Just keep cleaning until it comes out clean .. thats it!
There may be a small amount of oil, which would be 'normal'. But it could be a lot of oil too.

At the risk of stating the obvious!
Oil is viscous so flows slowly, so it'll take some time for just the oil to completely flow out on it's own. The cleaning fluid just quickens up the process.

The main reason for cleaning the IC is to eliminate the probability that all you're seeing is collected oil getting through the intake and burning off in the engine(at this point).
ie. once clean, take for drives and see if it still runs smokey all the time, or has it reduced a bit, or only at idle .. etc.

Note that if it has oil in the IC, then for sure it'll have oil build up through the rest of the intake .. IC hoses, intake manifold etc. So it could take a bit of time for it to fully clear a little(if this is the problem).
Otherwise you could remove the intake and hoses and clean them up too. Hoses come of easily and so does intake manifold(which isn't as hard as it will first appear).

FWIW: I think my turbo seals are worn. I sometimes get a huge plume of grey/white smoke when accelerating hard(up to about 3.5-ish K RPM) with foot hard on the floor.
What happens is a 1 sec plume, which clears completely to not visible in daylight.
It always has a slight hazy smokey emission only seen in the dark with light coming from behind me when accelerating.

I'd think that after cleaning the IC and finding out if it's made any difference to smoke levels .. or not .. come back and reply with results.