- 204ps Bi-Turbo CXEB T6 Engine & Turbo problems -

[kiteboardkid]

So after have a whole new Bi-turbo system was fitted under the All-in warranty back in Feb @ 43k mls (luckily they never detected it had EGR, DPF + Ad blue delete). I've only done 2256 mls since then. I topped up the oil 1124 miles ago as don't believe they topped it properly after the turbo warranty work, which included an oil change. Dip stick now shows approx 2/3 full, so definitely using some oil.

Has anyone tried running 5w-40? What are you thoughts on this? Could it possibly help with slowing down oil consumption?
PS. I'm no mechanic but have done a little research.

 

[DXX]

You don’t know that the oil is being lost through the turbochargers.
I’ve mentioned elsewhere that it’s worth fitting an oil trap between the PCV and the induction to prove the PCV is effective.
I put 5w40 in an Audi AJM TDI that I thought was passing oil via the turbocharger. It turned out to be a defective PCV.

 

[kiteboardkid]

You don’t know that the oil is being lost through the turbochargers.
I’ve mentioned elsewhere that it’s worth fitting an oil trap between the PCV and the induction to prove the PCV is effective.
I put 5w40 in an Audi AJM TDI that I thought was passing oil via the turbocharger. It turned out to be a defective PCV.

I wasn't suggesting it was. With the newly fitted and revised bi-turbos (according to part no.) that have now been fitted, I would certainly hope they not the cause of oil consumption. I'm assuming it could be the bores. I will look into fitting an oil trap. Is this a fairly simple task? Is there a dedicated oil trap that I should be looking for?

Thanks.

 

[DXX]

I wasn't suggesting it was. With the newly fitted and revised bi-turbos (according to part no.) that have now been fitted, I would certainly hope they not the cause of oil consumption. I'm assuming it could be the bores. I will look into fitting an oil trap. Is this a fairly simple task? Is there a dedicated oil trap that I should be looking for?

Thanks.

Have a Search on the Forum, somebody has done it already.
As to where to locate on my CFCA the only space is above the belts.
Make sure you don’t kink any hoses or you could over pressurise the crankcase and damage a crankshaft seal.
If it is the bores the additional blow-by maybe more than the OEM PCV can cope with.
If you can compare with another identical engine type van, just leave the oil filler cap balanced on the cover with the engine ticking over, you’ll get a comparison of the crankcase pressure.

 

[TacticalBrick]

I'm unsure where to go with my oil consumption on my 2018 CXEB. It's in the specialist and they said there's something that they can easily look at around the turbo, but didn't elaborate. (It's going in for an oil sensor wiring issue, not a full oil loss diagnostic just yet.)

However, my DPF is regenerating around every 150 miles. The differential pressure on VAG DPF when idle is 8-10 (hPa). It's at 75k miles and had a new EGR cooler 1k miles ago. If it's burning oil is this a gradual thing where the regens gets closer and closer together, or does it suddenly block up?

 

[WoopsBoughtT6]

Update from me.

Had the turbo unit swapped at Retro Resus a couple of weeks ago and have done circa 700miles since. Hasnt used a drop of oil (to the un-calibrated eye)

Hindsight looks like i could have got the new turbo done a bit cheaper elsewhere. However after two garages just telling me the engines knackered happy to have visited RR for diagnosis and sequent works. Highly recommend them and would happily travel the distance if any further issues develop.

Annoyingly don't have any diagnosis on the issue with the turbo, would have been good to understand what the issue was as it didnt show any signs of an issue when driving it.

Now just need to put it behind me and trust that it might not develop the engine bore issue that's mentioned in this thread...

 

[DXX]

If it's burning oil is this a gradual thing where the regens gets closer and closer together, or does it suddenly block up?

The general rule with any unmaintained filtration is that with a constant quantity of fluid being filtered (exhaust gas) the available filtration media reduces at an increasingly faster rate during the lifespan of the filter.

 

[DrPhill]

This is a great article - very informative. Thank you.

So if I am looking at a transporter and it has a CXEB engine should I just quietly walk away? Or is there something that could be done to determine the risk?


Thanks in advance for any advice......

 

[Kind of Blue]

I would not but those in the upper echelons of technical ability on here might give more specific technical advice. the other thing is I understand that not every CXEB engine was affected for some reason. I know not why it may be a lottery perhaps from an official VW centre with guarantees and warrantees but doubt they have vehicles of that sort or age premises???

 

[DXX]

This is a great article - very informative. Thank you.

So if I am looking at a transporter and it has a CXEB engine should I just quietly walk away? Or is there something that could be done to determine the risk?

View attachment 300555
Thanks in advance for any advice......

I’d pass on the fact that whoever put the ad’ together hasn’t counted half of the valves!
Seriously if the price is cheap, if you can afford to run and repair it and can do the work yourself then it’s an option.
Service history is only as good as the honesty of the data input and the quality of the mechanic.
A off the cuff oil sample analysis without notice might reveal a lemon, worth doing for £40 IMO.

 

[DrPhill]

A off the cuff oil sample analysis without notice might reveal a lemon, worth doing for £40 IMO.

Thank you, but that is something of which I have no experience..... I would appreciate some more information or a link or something.

 

[TacticalBrick]

It's a 2020 CXEB, so it'll have the engine with the modified pistons won't it? I thought they were OK? I still wouldn't touch one with a barge pole knowing what I know now though. The BiTurbos are harder to work on in general so more labour costs and the turbo is a single unit for the small and large turbo, which makes it a very expensive point of failure (~£4,000 inc labour).

Thank you, but that is something of which I have no experience..... I would appreciate some more information or a link or something.

Vision Oil Analysis

Reduce the risk of unscheduled downtime and costly breakdowns for your vehicles or machinery using Millers Oils Oil Sample Analysis.

www.millersoils.co.uk

 

[DrPhill]

It's a 2020 CXEB, so it'll have the engine with the modified pistons won't it? I thought they were OK? I still wouldn't touch one with a barge pole knowing what I know now though. The BiTurbos are harder to work on in general so more labour costs and the turbo is a single unit for the small and large turbo, which makes it a very expensive point of failure (~£4,000 inc labour).

Vision Oil Analysis

Reduce the risk of unscheduled downtime and costly breakdowns for your vehicles or machinery using Millers Oils Oil Sample Analysis.

www.millersoils.co.uk

Thanks for that......
How often do the turbos fail and need replacement?

 

[TacticalBrick]

How often do the turbos fail and need replacement?

From this thread and Facebook groups, much earlier than they should.

 

[DXX]

Thank you, but that is something of which I have no experience..... I would appreciate some more information or a link or something.

The link to purchase the kit is there above.
Instructions are in the kit.
You’ll also need a small clean syringe and approx 1m of clean preferable clear plastic hose to fit the syringe and fit down the dipstick tube.
From memory the sample is 80mL.
Cleanliness is imperative to avoid false reports of contaminants.
You’ll need to enter the data accurately on the form so you’ll need the oil manufacturer, grade and last oil change mileage.
Post the sample in the container / bag provided. Results take a couple of days to receive via email.
The analysis report will show if the oil is a pass or fail. It will also show contamination metallic elements, soot and fuel.
If the van has been on the extended oil change interval walk away, they need to have an oil change at approx 8-10K miles to be sure of maintaining good oil quality.

 

[DXX]

Thanks for that......
How often do the turbos fail and need replacement?

Hopefully never, it’s not a consumable item.
Lifetime is dependent on maintenance and how it’s been driven.

 

[TacticalBrick]

Add me to the list of 2018 204 failures; thankfully I managed to return it to the dealer. I'll be buying another one, but I think I'll be looking out for a T6.1 150 this time.

 

[C ROSSETTI]

Another possible 2016 CXEB diesel 204bhp engine/turbo problem.

Van made weird air noise from engine and went into limp mode. When I tried to accelerate coil light started to flash. Struggled to get home. Turn off/on, not sort it. Then noticed intermittent rattle from engine. Obd11 code P029900 turbo underboost and noticed older fault 2k miles ago P046C00 EGR sensor A circuit range.
Pendle engine and dsg map been on since Feb 2023, with 270bhp. Van now on 40k miles. Regularly serviced, driven conservatively ish, and been amazing up until now.
A mechanic friend has checked turbo's. They seem ok, bit of sidewards play on small turbo which might be the issue. Bit of oil in pipes, and some fine alloy shavings in pipes and intercooler/charge cooler.
Thinking of sending turbo's in for rebuild. But wishful thinking it might be intercooler/charge cooler. (And reading all the CXEB failure messages it might also be a whole host of other things )
Mechanic mate coming over again for further diagnosis.
If anyone has had any similar symptoms please let me know.

 

[mmi]

P029900 turbo underboost

Thinking of sending turbo's in for rebuild.

Perhaps a couple of checks to consider before -

Post in thread 'Vw t6 cxfa p0299'

1 May 2025

I would start by verifying boost pressure sensor readings - engine stopped should read the same as ambient air pressure.
Then verify that the turbo actuator runs freely from end to end.

These threads might be useful

For the boost pressure sensor​

Turbo actuator testing​

Fault diagnosis​

• mmi

• 

 

[DXX]

I hope for the best but squeezing 270 PS out of an engine that has reliability issues at the stock 204 PS is not likely to end well unless you race it for a living and rebuild the engine on a regular basis.
More power means more fuel, more exhaust gas, turbocharger rotors running well past the design max’ RPM.