X5 Lack of Power / Black Smoke
 

G’Day,

I've only just joined this forum but I've gained much useful information over time from it by browsing the threads. :thumbup:

I've driven a 3.0 X5 2003 diesel automatic for 5 years without any major issues but I've been having a problem over the past couple of months which I'm hoping you kind people could provide me with advice that may help sort my problem.

Sorry for the long explanation but here goes.........

Around 2 months ago I experienced reduced power when accelerating - it sticks at around 1500 rpm when pulling away at which point I get a ploom of black smoke from the exhaust before the power eventually kicks in. If I put my foot down I also get a large ploom of black smoke from the exhaust.

I initially took the car to the BMW dealer who put it on the diagnostic machine and recommended a new fuel filter, new EGR valve and new glow plugs.

This did not resolve the situation so I took it back to the BMW dealer who recommended a new mass air flow (MAF) sensor.

This improved the lack of power / black smoke for a couple of weeks but I'm now back to square one. I get the feeling the dealer is just experimenting at my expense without really knowing what the problem / solution is.:rolleyes:

I've also taken it to an independant who says there are no leaks or loose connections to the turbo.

Can you people please offer me any advice as to what my problem is?

Any advice is greatly appreciated.

Thanks in advance.
ED.

I've had bad experiences with BMW dealers diagnosing problems with my diesel.
It will be well worth your while finding a diesel specialist.

Black smoke is usually caused by over fueling or not enough air.
As you also have a lack of power it does tend to point to a problem with the air supply - and that tends to point to the turbo.
Air leaks would be the first place to check. Where/what did the you're indie check. There are a lot of pipes from the turbo, including th intercooler - all of these would need checking first.
Another problem could be the turbo itself, a sticking waste gate could cause a lack of pressure or the turbo could just be on its way out.
Start by checking all the hoses and connections (i.e. the cheap bits!).

Thanks for that Laurence.

As far as I'm aware the independant checked all connections to the turbo but I'll double check.

Thanks again - appreciated.

ED.

Any updates? I am having a very similar issue. Mine is an 05 3.0d

Check the air-filter first...This is often overlooked ,even by dealers.
The fuel pressure sensor is also a common culprit.
You say that after replacing the MAF car was good for a while,before you got the black smoke again!Dont ignore the fact that even the new MAF could have failed.
Have you checked the engine breather?
Have you checked if EGR is stuck closed...?Pull out the vacuum pipe from egr valve and scew in a 6mm screw on pipe and test car.
Also check the turbo VNT (N75) valves as these have a wire filter that gets blocked.
IF after all this and after checking all the pipe connections ,as Lawrence suggested,car is still the same,then it can only be the turbo and intermitent sticking vanes.

The EGR valve was replaced by the stealer a while back and that didn't solve the problem.

I've booked the car into a diesel specialist later in the month as suggested by Laurence. However, I replaced the air filter yesterday (using instructions from this site) and it is performing a lot better. I'm going to watch it for a week and if it stays OK I'll cancel the diesel specialist.

Forgetting my manners - thanks for the further advice powers1.

Glad to be of help...:thumbup:

Update
 

Hi peeps,, just wondering if there was an update on this as I am currently going through the exact same thing, it’s driving me nuts.
Just replaced
Air filter
Crank mass sensor
Glow plugs
Injectors cleaned.
Egr cleaner
And still the problem is here..

Can anyone please help??

What engine (year)? And any codes (from a BMW system scanner)?

Plenty of items that could casue this, so it's a matter of narrowing it down a bit...