BMW 320d 2003 manual

Do you have an increase in smoke from the tail pipe? If so I would have the turbo checked. Sounds like you may have lost the turbo boost due to the low RPM. Let me know if this helps? Viking.

HI Derek.

There are a few possibilities that come to mind.
3K RPM is generally about the break-even point for when Turbo boost would kick in. There is a dump valve on the turbo system that opens up and vents the extra turbo pressure under high-rpm situations where the boost isn't needed - say high but steady speed on a freeway. If the dump valve system is malfunctioning, then that anticipated turbo run-up in power won't happen.

Revving fine when in neutral may not tell you much, other than that the engine can rev. The gating system will (or should) run differently under load - whether climbing a hill or accelerating, this is where you want the turbo boost to give you the extra power. THat's where the exhaust gate should stay shut, or mostly shut, to allow the turbo to force more air into the pistons.

You might want to check whether the APC (Automatic Performance Control) for the turbo has a separate fuse. (The name might be different on your model, I'm remembering from my 80s/90s era Saabs). If the fuse is blown, that could also lead to lame performance, especially as I'd imagine that the system would be built to fail or go to full open if the APC fails or loses power - that'd keep people from having run-away power that they can't manage.

Hoping this helps

D

Have you checked the PCV system?? If its stuck in the closed position then you will lack power and turbo boost. A vehicle needs 3 things to make it run proper; FUEL,FIRE and AIR. Try that and see if it helps.

turbos generate boost fro the heat in the exhaust and the free flow of exhaust gases. That means the amount of fuel through the injectors and blocked cat converter or exhaust system. OK now you know how the boost is generated look for areas that will loose the pressure (boost ) between the turbo and the manifold Look for loose boost hose clamps on the turbo and intercooler and intercooler and manifold. Look for cracks or holes in intercooler. Look for blocked air cleaner as turbos use more air through the air cleaner than normal. Finally look at the compressor blade of the turbo as any bent fin will slow down the turbo wheel giving less boost. Have the turbo tested for correct operation

You might have transmission problem. It could be low fluid level or could be an internal transmission failure. I suggest you to have the fluid level checked for quality. Another thing you can try to reset your transmission. BMW transmission would help you to know about the transmission better.

It is but not good, the turbo from a diesel has a lower compressor rate due to the diesel engine has a lower RPM ratting then your Stroker. The higher RPM your engine revs, the more of a restriction to your exhaust from the turbo causing your valves to over heat and then your burn a hole through them or your pistons.
A good size would be a T70 with a 0,96 AR exhaust and if your looking to get more power get the T76 with the 0.96 AR exhaust side. Guessing that the T70 should give you around 550 HP low boost (10 to 12 PSI) and about 600 HP (15 to 18 PSI) around 4000 RPM. Your compression should also be around 8.5:1, anything higher and your going to have detonation issues during your midrange and up and to nuts off your torque ratio that your just going to burn your tires during your boost stage.
Hope this helps explained the difference in diesel turbo and gas engine turbo and i vote for the T70B with 0.96 AR hot side.
Thank you for using fixya and good luck

my 1.9 polo dti revs to 3000 then losses all power and starts to smoke

dear friend:a turbo can only boost the air that it receives,if the turbo is not damaged it should work properly,the turbo depends on the exhaust gasses for the speed that it turns which then boosts the air that it receives,that means that any restrictions on either side of theturbo will influens the preformance,check the air filter and ducting pipes.

The turbos are terrible on the 320d. If you plan on keeping the car get a new turbo. £950 from BMW themselves. You will get a 1 or 2 year warranty on the turbo. Well worth it.

Have you got an aftermarket computer? If not then the problem could be related to the factory ecu previously detecting a bit of knock as boost came on and now it may of changed its map to ****** the timing around this area. If you remove the battery + for a while and plug it back up it should clear the ecu's corrections. If it still is'nt going very well then you could try changing the spark plugs its amazing how dull they can make the power come on when they get tired.