[Aussie Ed]

Just a vague possibility but could the DPF be 'exhausted' ? The inner active coating of the PDF module does deteriorate over time and loose its effectiveness.
The vehicle is a 2012 model and 13 years old. A possibility maybe.

 

[Dd49]

Hello.

Yes, to answer your questions, I'll check the diagnostic measurements before going on vacation, but I don't think I'll be able to repair it in the meantime because I'm leaving at noon on Thursday and I have a lot of work right now, including firefighter duty.

It runs perfectly apart from the regeneration issue and the jerking between 1500 and 2000 rpm.

Now that I finally have a fault code, I'll be able to work on it.

The turbocharger CHRA is new, but maybe the turbocharger valve is faulty?! Or maybe the vacuum solenoid valve?!

Lots of things to check and options to rule out...

As a reminder, the DPF is new and has between 10000 and 15000km.

Thanks again to everyone, fingers crossed 🤞

 

[Dd49]

Hello,

So I had time in the winter to do some tinkering and diagnostic measurements.

I also bought another lambda sensor to rule out any possible causes.

If nothing changes, I could get a refund.

I cleaned and reprogrammed each sensor. Turbo, EGR, MAF, airflow sensor, DPF sensor, lambda sensor, everything I could do.

I managed to measure the turbo pressure.

In neutral,

750 rpm, I'm at 0.6 psi.

2,000 rpm, I'm at 4 psi.

Apparently (found online), I need a pressure of 6 psi at 2,000 rpm.

I noticed that it's difficult to stabilize at 2,000 rpm. The engine speed is not consistent. You can hear the engine suffocating or the turbo trying to stabilize.

I think I'm slowly getting closer to the problem.

Have a good week, everyone.

 

[Aussie Ed]

Dd49, You have certainly worked hard on trying to resolve.
What has prompted me to make an observation has been your reference to the 'engine seeming to suffocate'.
This word 'suffocate' stirred' my memory to a very long ago post on this forum (probably 8-10 years ago) which used the word 'suffocate'.
It turned out to be the air feed hose from the turbo which was quite sound visually with no splits or tears/holes, but the composition of the 'rubber' had lost its integrity of structure.
Once it became warm/hot in the engine bay the hose became 'soft and pliable' and would 'suck flat' under load thus reducing the available air flow (suffocate/restrict) the air input.
This is just a 'maybe possibility'. If you have already replaced this section of hose then ignore this post, if not, then it may be worthwhile considering this as a possible cause.

 

[Dd49]

Hello.

Yes, indeed, a very good point and suggestion!

Indeed, I just arrived on site.

I left home at 3% saturation (for 10 km) and arrived there without stopping on a national road at an average of about 80 km/h. I reached 98% saturation for 280 km.

Still the same from 1500 rpm to 2500 (worse at 2200 rpm), the car shakes, and if I release the accelerator to slow down, the turbo makes a strange suction noise and the engine chokes.

As if a hose had been disconnected, an instantaneous course.

What you're saying is entirely possible 👍

I'm coming back on Sunday, I'll check it out next week.

In the meantime, she gave me another fault code that could be related, once again, to an air problem.

Good afternoon,

 

[Dd49]

Hello everyone.

I'm back home.

Leaving there, I had to disconnect my air flow meter to prevent the car from polluting the entire village and underground parking lot where I was.

The regeneration was underway! I was at 98% for 250 km (I made a mistake when I said 280 km in my previous post).

Once I got stuck in traffic, I continued driving with the airflow meter disconnected and thought, "Oh, I'll keep going like this."

I connected my diagnostics with the instantaneous reading, and the saturation value showed 42% for 260 km. I was amazed!

The whole way along the road, the car ran great. I was in heaven.

Everything worked great, no engine misfire, no injector clicking, no jolting, the power was there and the ride was smooth.

I've rarely experienced it like that.

When I got home, my car showed 62% for 495 km.

If I reconnect the airflow meter, it showed 98%.

Now, by monitoring the instantaneous values, I'm thinking:

Either the EGR valve is faulty because disconnecting the airflow meter caused the EGR valve to no longer work.

Or the airflow meter is faulty despite having replaced it.

As for the turbo hose when the engine is hot, it's quite hard to bend, so I can rule out this hypothesis, which seemed very likely.

I remember a thread I read extensively before posting my problem.

This person had the same problem as me, and I was wondering if he managed to find the cause.

He also mentioned a faulty DPF or an airflow meter problem.

I remain convinced that my car is regenerating in a vacuum or with a half-loaded DPF.

To be continued 😉

https://www.chevroletownersclub.co.uk/threads/dpf-issues.8576/?post_id=49324&nested_view=1&sortby=oldest#post-49324

 

[Charly Mike]

That would be me. The same issue, except what I disconnected and it showed me the correct values was the differential pressure sensor, not the MAF. What made me replace it too, twice. With no luck... I can only tell, the DPF was the issue and non of the other parts I replaced, wasting money and time trying to solve the issue...

 

[Dd49]

Hello everyone.

I sent a message to the person in the same situation as me, Charly Mike.

Despite the number of years that had passed since his post was created, I wasn't expecting a response.

But against all expectations, he replied that, in his opinion, the retrofit particulate filter wasn't the same design or as efficient as the original filter. This was interfering with the sensors and triggering regenerations all the time.

Perhaps the solution was to re-configure the new filter's data in the ECU.

I'm now wondering, and for those of you who have the appropriate diagnostic tool for the Chevrolet, Is it possible to re-configure the new particulate filter values in the ECU using the special Chevrolet diagnostic tool?

I'm not talking about resetting it (because I've already done that several times), but rather about re-configuring a new type of calculation?

I don't think that's possible! Because it would be more likely that a car reprogrammer could modify this parameter, but I'm wondering.

Economically, it would be easier to get a special Chevrolet diagnostic kit than a new original particulate filter.

I would also add that it's more complicated in France now to remove the particulate filter, given the new environmental laws that will become stricter in the coming months.

Edit Is it possible to drive with the airflow meter disconnected? This would of course create a fault code, but would regeneration still start?

I also found a fault on my particle filter compared to the original. I will let you know about it soon so that we can get your opinion.

David

 

[Dd49]

So after getting Charly Mike's answer, a theory came to me!

I compared the two particulate filters some time ago when I disassembled them.

I emptied the original filter to continue driving and checked the new one with a tiny camera.
At the time, I thought it was designed for that!

I noticed that the pressure tube at the top of the particulate filter was straight on the original filter, and on the retrofit filter, the tube was bent and extended up to just above the DPF filter.

I wonder if this might be distorting the pressure calculations.

Now, after thinking about it, this seems logical to me because the pressure would always remain trapped in the tube, unlike the original, which is horizontal in the filter.

Perhaps a theory worth considering, given that I have everything I need for cutting and welding (I used to work with metal) and that I have some free time this weekend. I'd like to try to transform it. After all, I'm not going to give it a miss!

What do you think?

 

[Aussiecageman]

So after getting Charly Mike's answer, a theory came to me!

I compared the two particulate filters some time ago when I disassembled them.

I emptied the original filter to continue driving and checked the new one with a tiny camera.
At the time, I thought it was designed for that!

I noticed that the pressure tube at the top of the particulate filter was straight on the original filter, and on the retrofit filter, the tube was bent and extended up to just above the DPF filter.

I wonder if this might be distorting the pressure calculations.

Now, after thinking about it, this seems logical to me because the pressure would always remain trapped in the tube, unlike the original, which is horizontal in the filter.

Perhaps a theory worth considering, given that I have everything I need for cutting and welding (I used to work with metal) and that I have some free time this weekend. I'd like to try to transform it. After all, I'm not going to give it a miss!

What do you think?


View attachment 3413

View attachment 3414

Different tube placement can definitely throw off the dpf reading. I think an autotuner can optimise the dpf for you, I don't think this is possible in SPS. I will have a look to see what I can find.

Cutting the tube is also a great option, cumbersome to do but if you have the expertise than yeah definitely worthwhile!

 

[Charly Mike]

WoW! That's an extremely interesting approach! So, the original one messes the pressure built in the middle chamber and the aftermarket one takes the pressure values from the beginning of the DPF.... Well, you just made an amazing discovery! Because the main issue with it, it's the pressure!

 

[Dd49]

I'll try to take some pictures of the other particulate filter this evening and work on this transformation this weekend.
If only it could be that, it would be magnificent.
Fingers crossed.

 

[Dd49]

Good evening everyone.

Some feedback on this temperamental particulate filter!
J'ai vérifié avec le petit appareil photo, et il a définitivement un tube comme sur l'original !

Ce que j'ai vu la première fois, ou du moins ce que j'ai cru voir, ce sont les vis qui maintiennent le catalyseur ! Visibles depuis la sonde lambda.

I managed to insert the camera into the vacuum pipe in the center of the DPF.
It was in pretty good condition.

Cependant, mon FAP est monté à 110 %. J'ai effectué deux régénérations forcées, et la situation n'a fait qu'empirer. Il est monté à 130 %.

In addition, the car is increasingly misfiring around 1800 rpm. Still no fault codes! As if an injector was seized!
I'm throwing in the towel; I'm fed up with this car.
I might have found a diesel mechanic who could take it from me in 3 weeks. In any case, I'll keep you posted.

Have a good week.
David

 

[Aussiecageman]

Good evening everyone.

Some feedback on this temperamental particulate filter!
J'ai vérifié avec le petit appareil photo, et il a définitivement un tube comme sur l'original !

View attachment 3421

Ce que j'ai vu la première fois, ou du moins ce que j'ai cru voir, ce sont les vis qui maintiennent le catalyseur ! Visibles depuis la sonde lambda.

View attachment 3425

I managed to insert the camera into the vacuum pipe in the center of the DPF.
It was in pretty good condition.

View attachment 3423

Cependant, mon FAP est monté à 110 %. J'ai effectué deux régénérations forcées, et la situation n'a fait qu'empirer. Il est monté à 130 %.

View attachment 3424

In addition, the car is increasingly misfiring around 1800 rpm. Still no fault codes! As if an injector was seized!
I'm throwing in the towel; I'm fed up with this car.
I might have found a diesel mechanic who could take it from me in 3 weeks. In any case, I'll keep you posted.

Have a good week.
David

David, je suis desole que votre tentatives n'etait pas reussi. J'espere que le mécanicienne aurait une solution.

[I'm sorry your attempts weren't succesful David. I hope the mechanic has a solution].

 

[Dd49]

Hello

Thank you.

Yes, I hope he finds it too!

I spent hours and hours researching and testing it.

Many weekends spent checking, cleaning, and cleaning all the parts...

My wife told me to stop! Either sell it or we find a mechanic.

I hope the diesel mechanic can do something about it because, once again, very few mechanics and dealerships are willing to repair, and especially diagnose, Chevrolets in our area. 😓

In any case, a huge thank you to everyone for your invaluable help and sharing your knowledge.

I promise I'll keep you posted no matter what.

Have a good day everyone.

David

 

[raffo77]

I had a quick read off all pages. First of all, thanks to the user who shared the gm tis. I had recently had my nas equipment die on me and lost my copy.

As for the issue complained by the OP, the delphi injectors have a "cartridge" inside them. Did these get changed?

 

[Dd49]

Hello.

Thank you for your suggestion.

Yes, indeed, the injectors were remanufactured by Dieselfitness, a German company. I think they were replaced, or at least I hope so!

I was provided with a sheet with the calibration information for each injector. With new coding.

Now, in hindsight, I think they're poor quality.

A person I know on the France Captiva Facebook page bought four injectors from the same place I did, and he's also having problems with them, but he doesn't have any regeneration issues.

I've read quite a few threads about Chevrolet Cruzes, which share the same engine as the Captiva, but with a 2.0L 163 horsepower engine, often having these smoke problems.

Some people also have this problem after replacing the DPF with an adaptable one, but they say that a problem had previously clogged their old DPF, without being able to find the cause.

Many people are talking about a regeneration temperature problem! Indeed, the DPF struggles to exceed 450°C during regeneration, when it should be at an average temperature of 600°C.

This would explain the smoke caused by the diesel fuel not burning properly in the particulate filter.

Good evening, everyone.

 

[raffo77]

For what I have read these cartridges wear out and cannot be regenerated, unfortunately. I have no direct experience as my captiva is a series 1 with bosch injectors.

 

[ches]

In my case the DPF is cracked almost in half (vertical crack from top to bottom), I don't know why, but it was observed when I changed the timing chain. The DPF regenerations are still going fine, every 800km it automatically starts one. I also observed that the car is not very happy if the regenerations are not complete. Fortunatelly I use my car mostly to drive outside the city, so this is not happening too often. I did not saw regenerations started due to DPF soot reaching a threshold, but only due to reaching the 800km threshold between regenerations. But this monitoring was done nonly in the last year when I bought an OBD interface that can read the soot level and the distance traveled since the last regeneration.

Observing what i wrote above, I am thinking that if you can crack your DPF or make some narrow holes in it (I think holes can be calibrated easier). This will let the exhaust gases go out, but you will still have a pressure difference that is big enough not to trigger a DPF pressure sensor fault.

 

[Dd49]

Hello

Thanks for the feedback.

For my part, the DPF is in good condition.

I checked it again with the camera from the top, middle, and bottom; no anomalies were noted. No cracks or breakages.

I drove 250 km twice this weekend on a national road.

I had to disconnect the EGR valve because the shaking gets worse when it's activated.

Even with less shaking, I managed to make it without too many problems.

Oddly enough, the DPF is currently at 606 km at 64% saturation. Which is a good performance for me.

I would have thought the EGR valve was the culprit, but since I still have the jerking with the valve disconnected, I think the problem lies elsewhere.

I'm currently traveling to another region for work.

I was recommended a very good mechanic. I have an appointment with him on Monday evening.

He gave me the car and ran several diagnostics to determine the cause for €60.

I spoke with him at length, explaining all the mechanical work I'd done on the car.

He told me that remanufactured injectors on this type of model (Delphi) were a big mistake; it was essential to start from new because they are very fragile.

He hasn't ruled out an injector problem, but he's also considering a rail pressure sensor issue or an electrical fault.

I'll know more Monday evening with a detailed quote.

Just to be honest, he told me that the four injectors cost €1,400 new, and that at that price, you had to be sure you weren't making a mistake before replacing parts for nothing.

Have a
good week, everyone.