Is my Turbo on the way out?

[Mykel1234]

On a recent highway trip cruising at 100Km/h I went to overtake going up hill and notice no power and a lot of black smoke coming out the back.

I had my nanocom connected and notice that I'm unable to go over 1bar turbo pressure and when at idle the turbo pressure is at a negative reading.

My wastegate module is bypassed with the vaccumm hose connected directly to the intercooler hose. Also I have blanked the EGR. There does seem to be some play with the impeller shaft.

There are no faults logged on the nanocom, so does this sound like my turbo is on the way out? It seems fine driving around the city.

Your help and advice on this would be great.

[bsperka]

Could be the inlet turbo hose collapsing. What condition are they in?

[Blknight.aus]

sounds more like a hose splitting open under boost or delaminating and blocking at the bend.

[sierrafery]

That negative reading at idle is suspect and can be failed MAP or AAP sensor, check live data in fuelling inputs and see the ambient pressure compared to the maniford(turbo) pressure, they both should be close to 100 at idle, there's no specific fault code for the AAP sensor failure just that if it fails the default for it is 100 and if the real pressure there is lower the MAP will read that at idle and the result is negative, also the default for failed AAP is limited boost to 1 bar and black smoke, worth a check, though it can be failed MAP sensor too

The AAP sensor can fail the following ways or supply incorrect signal:
l Sensor open circuit.
l Short circuit to vehicle supply.
l Short circuit to vehicle earth.
l Contaminated sensor element.
l Damaged sensor element.
l Resistance in wiring harness.
In the event of an AAP sensor signal failure any of the following symptoms may be observed:
l Altitude compensation inoperative (engine will produce black smoke).
l Active boost control inoperative.
l Turbocharger boost pressure limited to 1 bar (14.5 lbf.in 2 ).
l EGR altitude compensation inoperative.
The MIL will not illuminate in an AAP sensor failure, and the ECM will use a fixed default value from its memory.

P.S. if you still have EGR make sure it's not clogged with muck

[Mykel1234]

Thanks for the replies.

I replaced the hoses about 3 months ago with Silicone ones as this same issue happened.

The MAP sensor is also new about a month old, so it might be the AAP sensor....rather try the cheaper solutions than replacing the turbo :D

Anymore advice?

[ramblingboy42]

what is the impeller shaft you mention?

[discorevy]

I'd suggest fitting a new boost modulator ,until then you can shorten the rod on the wastegate by 2-3 turns to compensate until you get the new one. Put a paint dot on the knurled nut before you turn it so you know your original setting. If , after doing this your boost is still at 1 bar, then it points more to sensor faults or partially stuck open wastegate , either way it's unlikely to be turbo .

[Mykel1234]

The shaft that has the turbo vanes on them.

Sent from my HP Pro Slate 8 using AULRO mobile app

[Mykel1234]

Thanks guys, replaced the boost modulator today and what a difference! The Disco pulls like a train and the turbo pressure on the nanocom is showing a maximum of 1.18bar, huge improvement.
Thanks again for all your suggestions and help.