Hi

The mongrel has started being in limp mode at tickover with boost coming in later in revs and not in usual manner. I have checked the vacuum hose and it's fine, so does this now point toward my n75 block playing up?

Ps, although Car boosts for a while, eventually full limp mode takes effect and no boost anywhere in rev range. Switching off and on again does reset it though which is why I am thinking it's electrical / vacuum linked.

Checked wiring to the map sensor?

Have you tried the a actuator test in VCDS to see if the pressure changes?

Also any group 11 logs at idle and casual driving?

Not done any of the above - I just removed the vacuum pipe and verified no leaks.  Not sure how an N75 block fault would manifest itself, but I have a feeling it would do what it is doing now.

N75 box on its way to me tomorrow.  Tomorrow evening I think I will run some group 11 logs to see if anything jumps out at me.  I can't see there being a map sensor issue as it would either be in limp mode, or not, and the symptoms are more aimed at the turbo vanes not opening up at tickover / low revs.

 

If the N75 box doesn't cure it, I think next step is to check the wiring from the N75 box back to wherever it goes.

I guess it's an electronic actuator? If not, can you manually free-up the actuator arm?

It's vacuum operated (but by electric signals to the n75 I guess) I was able to move the actuator a little from underneath so I don't believe that to be broken.

If you can manually exercise the actuator arm - then I guess it's positive...?

The N75 could be failing, however, a DTC has not registered? Have you inspected the vacuum pump and reservoir?

Is that the ball thing down the front?  Not checked that no.....  I've not checked the tandem pump either to be fair as never thought it could be linked.

Yeah,the orb, and also the remaining the vacuum pipework.

Done the VCDS basic settings, group 011?

Well I'll tell you wots the problem, it's your orbs init.

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Update on this issue?

Have n75 box, hoping to fit after work. If that doesn't sort I am booked in to mates garage in the morning for other small issue and shall get it checked then.

Replacement N75 fitted and now praying its sorted the issue (off out for a drive anyway in 20 mins....)

 

[fingers crossed!]

Not working still!  :(  No trying to find out what vacuum the actuator vacuum SHOULD pull and that will be tested tomorrow to check.  Might end up being a broken actuator yet.....

All working now!    Was a rubbed through vacuum pipe from Reservoir to the N75.  I hadn't spotted it as tucked out of sight.  Full power / boost restored!