Mc, slight hijack here but my transit runs shit sometimes. Full dealer history and just out-of warranty. It gets noisy, almost throaty when driving sometimes, almost sounds like it’s blowing around the manifold. It then seeks to hunt for diesel at low revs. Any symptoms sound familiar?
Hunting is typical of the ECU struggling to control fuel pressure, which is most noticeable at idle. Later updates seemed to of fixed most issues in that area, and make relearning the valve a much less painful process. Since the later updates, I’ve rarely had to change a fuel regulator solenoid.
Noise could be anything, but if no warning lights are coming on, I’d doubt there’s anything actually leaking from the boost side.
Might be a fuel pressure issue though, as the injection timing will vary to compensate. I’d certainly go for an update, and relearning the fuel regulator, before looking further.
One thing that does spring to mind, is if it’s a rear wheel drive, check the inlet tract to the air filter housing, as they often fall apart and rattle like f***, and makes you think something serious is wrong. A suitably placed cable tie to hold it together solves that problem.
