I had a similar prob with my 3.0d....it was a split exhaust manifold...worth a look!


Sent from my iPhone using Tapatalk

I agree.
If the engine is ok with very soft acceleration;
but then loses power and becomes noisy when you put your foot down;
the pressure building up if probably escaping;
and all those stainless steel manifolds leak.

If it was me I'd replace exhaust manifold with a cast iron one;
with the no egr pipe-
just blank it off at the manifold-
why over complicate things trying to figure out at what pressure the EGR opens or closes ...

Just eliminate all that and have well performing X5 again! :D

Sorry folks, should have mentioned that I've fitted an iron exhaust manifold when I originally changed the turbo. Knew they were weak points, so ordered one as made sense whilst i was in the area and knowing id be removing turbo. Turned out the original was starting to crack (very small) but would have got worse, so very glad i did order one!

Deepblonde, engine is noiser at idle as well as when driven and acceleration is lacking low down, even from standstill. In fact it's worse when slower than when already shifting along.

I've not removed the egr as introducing another variable, but have ran it disconnected (hose plugged of course) and made no difference, that I can recall. I will try this again though, as that was ages ago and likely before i changed a few parts. Will look for a blanking kit to, as worth a shot I guess and at least can rule out EGR issue. Although wouldn't it then throw errors which could hamper performance anyway?

I'm also going to try driving with maf held open to see if that helps with power, as definitely helps with noise, just need to find a suitable clip to pinch the hose off whilst under vac (or long hose to put hand vac in car lol

Cheers all

Well, just went to do a leak off test to see if issues could be injector related, and when started the car, diesel was pissing out of the leak off line. Had to stop the car obviously so no result of test, just wasted half a litre of diesel lol.

Is this normal, as didnt think the return line would be under pressure?

If normal, how do I stop the return line from dumping fuel everywhere whilst I complete the leak off test?

Thanks,

Hi

I know the last post is nearly a year old, but did you ever find the problem?

Nope, 2 grand in replacing bits and paying 4 garages (1 main bmw dealer, 1 one I bmw specialist and 2 normal garages) to diagnose and everyone says it's fine and can find no fault.

As she drives fine, albeit less go and noisier and poorer fuel economy, I've thrown in the towel and stopped looking.

You have any ideas?

No ideas, as I have the same problem, but only after it gets to operating temperature, and mine has now developed a lumpiness/vibration (like a miss in a petrol engine) that you can feel. I have gone through 3 garages, and they all say the same as yours. There is nothing wrong. I even had my regular mechanic drive it home one night (2 hour drive) and back to the garage (another 2 hour drive) and couldn't fault it. After a bit of an argument, telling him he shouldn't be a mechanic if he cant even feel the difference, I don't go to that garage anymore.

I was leading to injectors, but INPA shows the fuel trims are fine.

My next step was going to be injectors, but couldnt get inpa etc working and then my laptop bettery died completely. After that i suspecting clutch/transmission, but cant see how the latter would affect idle.

If yours is temp related, perhaps that's a big clue. Something nice and tight when cold, but thermal expansion causing an issue?

Mines loud and down all the time, at all temps. Can't be anything too major though, done about 14000 miles like this with not a blip of trouble lol, trust my most reliable car to be the broken one lol

Hi Upex,

I am having a fairly similar experience. Although my power is all fine (As my X5 has a remapped ECU from E-maps) It's certainly faster than standard 3.0d's however, I am experiencing injector issues (I think). I have been through the mill and checked off all the things you have listed and I now have INPA and a laptop that talks to my X5. I tested this at the weekend to clear my SRS airbag light after a fix and it worked! So, I also noticed a rough idle code but intermittent and fault not present. Looks like I need to do an Smooth Idle Test on INPA and see if any of the injectors are out of spec but is is slightly lumpy at idle now. When the injectors failed a couple of years ago, it was like someone hitting the steering wheel with a hammer and its currently nothing like that so I am hoping its just out of spec or needs a injector pulling and cleaning.

I will keep you up to date fella. Also might do a video of INPA smooth idle test but I am sure some of the good fellow on this site have already done it, but as its relevant I will do one.

Fingers crossed for you lamby

Appears these little, not quite right issues cropping up for few of us. Shame, as they pretty good motors.

Have you had any mechs check her out?

My idle solid, but fuel consumption getting worse. Flat roads on my commute and I'm getting low to mid 20s now, taking it easy. Used to be pushing mid high 30s on same route.