T6 4motion loss of power at 90km/h

[Carapapa]

Hello all!!

This is my first post on the forum. I just found it and I find the amount of information you share and the quality of the publications spectacular.

A week ago I changed the oil and all the filters on the van. Additionally, a few months ago I had to clean the particulate filter and catalyst using a liquid ultrasonic bath because the van stopped. Now I have a new problem but it is very random.

The van runs perfectly, it has a lot of power, but when I go on the highway in 5th gear and at 80-90km/h (with the air conditioning), sometimes and without warning it loses power. If I floor it the consumption goes up, it emits a lot of black smoke but it does not increase in speed or revolutions. The power remains limited and when I leave the highway in first and second gear it goes well, but in third it feels very limited and with the same problem. When I remove the contact and put it back in, everything returns to normal. I can get back on the highway and the problem doesn't appear again.

I leave you a video where you can see the problem, since I was able to record it the last time he did it to me. I'm saying what happens in Spanish (don't laugh too much)

Useful info: VW T6 4motion 150HP (remapped) 230,000Km

Thank you very much and I hope you find it interesting and you can help me!!

 

[Dellmassive]

Sounds like possible loss in turbo boost pressure?

150ps, so single turbo.

Possible sticking turbo vanes?

sticking bypass valve?

Have you got access to vcds? To post a full scan of data?

 

[Carapapa]

Here is the video!! I had to upload to YouTube

About turbo I thought the same but it is strange that only happens some times. I don't have VCDS but I should! I checked with Carista during and after the issue but it shows no errors, even in the code.

 

[Dellmassive]

No boost pressure?

.

But no engine warning lights?

Need a vcds scan.

 

[DXX]

I think Carista beta live data should show the boost pressure.

 

[Carapapa]

Using Carista yesterday, as you suggested, the boost gets deactivated when problem appears. Normally it gets 20 psi and respond normally to the gas pedal, but then it gets stuck in 2 psi.

Today the van is in the mechanic, so I will update whit the info that they get to me

 

[Dellmassive]

Keep is posted.

MAF sensor and boost pressure sensor, bypass valve and variable vane on turbocharger all will have an effect.

Though I would have expected to see a engine warning lights.

 

[DXX]

My money is on an intermittent N75 or actuator / control vacuum.

 

[Carapapa]

Hello guys! Quick update, yesterday I collected the van from workshop.

The problem was the butterfly valve from EGR system. They have cleaned the EGR, as far as I understood, with spray, they didn't take it out to do a Deep cleaning.

Now the van works much better than before, even before than the loss of power. The van exhausts less black smoke when I hit the gas and also I think fuel consumption has been reduced from 9.2 on average to 8.0 l/km. I have to test it more but looks very nice

 

[DXX]

Hello guys! Quick update, yesterday I collected the van from workshop.

The problem was the butterfly valve from EGR system. They have cleaned the EGR, as far as I understood, with spray, they didn't take it out to do a Deep cleaning.

Now the van works much better than before, even before than the loss of power. The van exhausts less black smoke when I hit the gas and also I think fuel consumption has been reduced from 9.2 on average to 8.0 l/km. I have to test it more but looks very nice

Are you still on the original EGR unit at 230000Km?

 

[Carapapa]

Actually I don't know because I bought the van like 8 months ago with 218.000 km. Other fix that seller cover me was ultrasound cleaning of the particle filter and catalyst few months ago.

 

[DXX]

The problem was the butterfly valve from EGR system.

From the EGRs I’ve looked at this is fairly normal when they are caked in carbon. If this was the cause of the lost power (boost) I’m surprised it isn’t a more common occurrence.
Please keep us updated.