New E53 Owner intro/Boost leak (I think)

[Supra]

Hi, My name is Shane and based in the UK.


I have recently bought a 2003 3.0d Manual. Its quite tired and done around 140K. I bought it to replace an old twin cab Nissan Navara and like that the X5 will be used as a daily and to tow my Mk4 Supra to the drag strip ocasionally.

Not new to BMWs, but I have been away for a while as I got into Jap stuff. My last was an e24 635csi about 15 years ago and before that had various E28s and even before that I owned a few E3s and a really early 530 (70s).

So, the new toy so far has been a nice experience and glad I made the move, much more refined than the Navara. From a driving point of view the power delivery reminds me very much of my old E300 TD Merc with the OM606 which I loved. It has the usual bits wrong, lcd needs a new display or ribbhon cable repairing, all the vacuum hoses under the inlet manifold were disintergrated and I had hoped this would cure my problem, but didn't.


Undler medium to heavy load conditions at around 2500 -3000 rpms I can feel boost fail and at the same time hear a hissing sound, Easing off the throttle and getting it back to vac cures it until the next time the boost builds up again and it repeats.

I have done a search and see the exhaust manifolds crack but I dont think its on the hot side. To me it sounds and feels more like a intercooler or hose split that gives out at a certain pressure. I also ready that sometimes the inlet manifold can crack, I took this off at the weekend to change the vacuum hoses (that was fun and a steep learning curve) and it looks in great shape so I am pretty sure its not that. I will see if I can block off the turbo end and put some compressed air down the system and listen for a leak. Any other suggestions? Also, I have been looking around here and youtube for clues to how the intercooler comes out, does the crash bar behind the bumper really have to come off to get the intercooler out? I should mention also that I have deleted the EGR but this problem was present before I did that so its not related to the EGR.

Would apreciate any direction on this, thanks.


Shane