# 2015 diesel-- No boost. Any ideas?



## HechoEnUSA (Aug 15, 2015)

2015 cruze diesel 190,000 miles. All stock. Started as intermittent P0299 and more frequent regens. Eventually got to point where it wont regen and now its parked. So checked vacuum pump/ lines all check normal, cant find a hole in the charge air cooler or the pipes, no signs of turbo failure and the the shaft still spins easy. TC vane position desired/actual match up. At idle its looking for 15 psi boost getting 1psi and anywhere off idle its 0psi. I learned while trying to figure this out the car needs an EGR cooler but it doesn't seem like that should be related to the boost issue. If anyone has any ideas or similar experiences id love to hear it before i just start changing parts. Thanks


----------



## MP81 (Jul 20, 2015)

@Snipesy


----------



## Tomko (Jun 1, 2013)

Here’s my diagnosis: Intercooler Air Inlet Hose and Intercooler Air Outlet Hose, P/N 95472183, 13247992, 22979688, 19420422.

Replace these and force another regen. All should be well after this.


----------



## snowwy66 (Nov 5, 2017)

On semis I've seen egr and delta sensors disable the turbo. Among other things. 

Sounds like #3 has the fix though.


----------



## 15cruzediesel (Sep 30, 2019)

Honestly with that many miles I'd check for a restricted throttle valve and I'd for sure check all the EGR piping for being clogged and also inspect the egr valve.

This of course is assuming you have no major charge pipe leaks or exhaust leaks.

Also scan it for any pending codes and post them on here.


----------



## 15cruzediesel (Sep 30, 2019)

BTW don't throw parts at it.
Diagnostics first.


----------



## Snipesy (Dec 7, 2015)

EGR and throttle valve is a good start.

But it could still be a failed VGT actuator or diaphragm. These issues do not give a CEL, and the Desired/Actual VGT position will still match.

At near 200k mi a stuck VGT diaphragm (the actual actuator on the turbo not the vacuum actuator) is not out of the question. This requires a disassembly and reapplying dry lube (eitheir nickel anti sieze, graphite powder, or a mix of those). This is a lost art and many just replace the entire turbo.

Unfortunately because of the vacuum testing the VGT is annoying.


----------



## Snipesy (Dec 7, 2015)

Excellent video if you have no idea wtf I am talking about





Obviously not our turbo but operation is similar.


----------



## HechoEnUSA (Aug 15, 2015)

Tomko said:


> Here’s my diagnosis: Intercooler Air Inlet Hose and Intercooler Air Outlet Hose, P/N 95472183, 13247992, 22979688, 19420422.
> 
> Replace these and force another regen. All should be well after this.


I've read this on here a lot. Just seems like youd still have some boost getting through Unless one was broken in half or had a gigantic hole in it. These are the parts i was gonna launch at it i just wanted some evidence before spending the money. I smoke tested the charge air system and they were good but i dont have a way to pressurize.


----------



## HechoEnUSA (Aug 15, 2015)

Snipesy said:


> EGR and throttle valve is a good start.
> 
> But it could still be a failed VGT actuator or diaphragm. These issues do not give a CEL, and the Desired/Actual VGT position will still match.
> 
> ...


Ive done this on duramax turbos back when i was a tech. Can you open up the CTD turbo and clean the vanes/unison ring and get it back together? I thought i had seen posts on here saying there is a gasket or something that leaks when you put the turbine side back together. Also the vane position desired/actual will change with throttle input they arent just stuck at one position. Could they still be too seized to produce boost?


----------



## HechoEnUSA (Aug 15, 2015)

15cruzediesel said:


> Honestly with that many miles I'd check for a restricted throttle valve and I'd for sure check all the EGR piping for being clogged and also inspect the egr valve.
> 
> This of course is assuming you have no major charge pipe leaks or exhaust leaks.
> 
> Also scan it for any pending codes and post them on here.


Ive had the egr and the butterfly valve off and cleaned (how i found out my cooler is fubared) codes are just P2463-DPF soot accumulation and then every few cycles it kicks out a P0299 under boost. Few times a P06DC oil solenoid high voltage sets then passed and clears. Balance rates have all been good, not pressuring crank case or coolant so i believe mechanically its alright not sure if my compression gauge even has an adapter for CTD glow plugs so hopefully doesn't come to that.


----------



## HechoEnUSA (Aug 15, 2015)

Thanks for your input, this site has fixed this car for me a handful of times before and it seems to be the only place ive found that knows much about these cars. Most shops and some dealer techs dont even know it exists so its a little scary having nowhere to go with it. I got lots of work hours till the weekend so ill work on it and post this weekend any new info.


----------



## 15cruzediesel (Sep 30, 2019)

One thing you could try is disconnect the DPF on the turbo side.

If it is clogged she'll make boost when it can breath on the assumption the DPF is clogged and 190k it might be.


----------



## Snipesy (Dec 7, 2015)

15cruzediesel said:


> One thing you could try is disconnect the DPF on the turbo side.
> 
> If it is clogged she'll make boost when it can breath on the assumption the DPF is clogged and 190k it might be.


If it was that bad it wouldn't start at all.


----------



## Snipesy (Dec 7, 2015)

HechoEnUSA said:


> Ive done this on duramax turbos back when i was a tech. Can you open up the CTD turbo and clean the vanes/unison ring and get it back together? I thought i had seen posts on here saying there is a gasket or something that leaks when you put the turbine side back together. Also the vane position desired/actual will change with throttle input they arent just stuck at one position. Could they still be too seized to produce boost?


I don't know I never tore apart these turbos. Theres probably only like 2 or 3 people in the USA who have.

But no you shouldn't need to tear apart the guts. Just the outside.

As for actually fixing it.... 
Turbo nozzle ring GTB1549V 786137 for Opel Insignia Astra Zafira 160HP 2.0 CDTI | eBay 
Turbo actuator GTB1549V 786137 for Opel Insignia Astra Zafira 160HP 118Kw 2.0 T | eBay 

Those might work? Probably? I have no idea. These parts and do not exist in the USA.


----------



## Snipesy (Dec 7, 2015)

HechoEnUSA said:


> Also the vane position desired/actual will change with throttle input they arent just stuck at one position.


I know. They are just not reliable. Several people have had vacuum problems that did not show anything wrong with the desired/actual.

I don't know why. I don't fully understand how that sensor works.


----------



## 15cruzediesel (Sep 30, 2019)

Snipesy said:


> If it was that bad it wouldn't start at all.


The fact he gets 1 psi at idle and any thing off idle 0, makes me suspicious of an exhaust restriction since he said egr and charge pipe is ok. He also states a dpf soot accumulation code that has come and gone.🤔

Either way it cost nothing but time to do that test and it is one less thing to diagnose.

I'd like to see graphs of the specified boost value and the actual value while doing the diag.

I'd also want to understand why it wont regen now also.


----------

