Disconnected the charge pressure regulator

norway2 · #1 09-08-2018, 09:45 AM

Hi
Have a x5 2004 model E53 diesel, it turns out that the previous owner has disconnected the charge pressure regulator (cutting the hoses) assuming that he has done because it did not work, then the entire turbo must be replaced or the pressure regulator is a separate part that can replaced?
Is it harmful to the motor to drive the car like that in a period
The workshop also found a stored fault on cylinder balancing, could this be a serious / expensive mistake to fix?

wpoll · #2 09-08-2018, 04:25 PM

I'm not sure if your cylinder balance issue is as a result of the charge control being disabled but I certainly wouldn't be testing cylinder balance with the charge control disabled - the test is not valid.

The charge control is required to adjust the turbo geometry for optimal boost at all RPMs. Without this functioning, the engine will run poorly. It's probably ok to drive a little with the charge control not working but I personally wouldn't drive very far, as the engine will not be working very well at all.

https://www.newtis.info/tisv2/a/en/e...tuator/XcGISOp

Once the charge control is fixed you can then revisit the cylinder balance. If a cylinder balance issue still exists, it's likely an injector problem. The cylinder balance test will need a properly running charge control to be a valid test though....

norway2 · #3 09-09-2018, 06:07 AM

Thank you for explaining, many skilled people in this forum :-)
I found the turbo problem, there were 2 hoses that were not connected to the vacuum tank, amazing that the BMW workshop did not fix it when the car was there, I spent 10 minutes fixing it and it felt like the engine got 50 hp extra and it went a lot smoother. Could there be any reason why the previous owner has disconnected the hoses?

wpoll · #4 09-09-2018, 05:25 PM

Glad the car is running better.

I cannot guess as to why the two vacuum lines were disconnected - and if it was deliberate then they should have been plugged, as having them open compromises other vacuum systems.

But there's very few good reasons to unplug these - only one I can think of is to diagnose the system - but you would the re-connect them after the diagnosis...

And as for a BMW workshop that would run tests like cylinder balance etc. and not pick this simple issue up....? Lets just say that this is a public forum, so I'll keep my comments to myself...!