T6 150ps engine problems

[Matt maz]

Hi all, I’ve just recently starting having issues with my 2018 T6 (150ps). There’s a lot of engine vibration on idle up to 1500rpm, a bad smell of unburnt diesel and a lot of white smoke for around 10mins until it’s warmed up. It’s covered 105k (miles) but sits on the motorway and doesn’t really cover short journeys (hence the high milage for the age)
It’s got all the symptoms of the biturbo EGR problems but I can’t find anyone that’s had this problem with this engine. Has anyone had this issue?
No warning lights on. Fuel filter/ oil filter changed. No sludge in the oil filler and old oil looks free of debris. Engine runs like garbage until it warms up then the vibrations are intermittent. Any ideas?

 

[Dellmassive]

leaking injector? (into cylinder)

white smoke + diesel smell. . . . . . . is unburnt diesel out back.

stuck EGR valve maybe . . ? causing fuel/air mix to be upset?

maybe book it into VW for a diagnostic . . . . then take to a local indy for the repair?


+++

or just take to a VW Indy, but risk a possible miss diagnosis.

 

[Matt maz]

Thanks Dellmassive, it’s in to VW on Wednesday.
It’s been to a VW specialist for diagnostic which found a fault stored for torque cylinder 1 and a sporadic deviation on the injectors.
They advised taking if for a compression test as they suspected piston wear! On a van that’s 3 yrs old I thought was a bit of a joke. This then put me on to the rabbit hole with the EGR biturbo issue. I just wanted to know if anyone has experienced this problem with the single turbo engine?

 

[Dellmassive]

gotcha . .

im still thinking leaking injector.

keep us posted with the VW findings.

 

[DXX]

Thanks Dellmassive, it’s in to VW on Wednesday.
It’s been to a VW specialist for diagnostic which found a fault stored for torque cylinder 1 and a sporadic deviation on the injectors.
They advised taking if for a compression test as they suspected piston wear! On a van that’s 3 yrs old I thought was a bit of a joke. This then put me on to the rabbit hole with the EGR biturbo issue. I just wanted to know if anyone has experienced this problem with the single turbo engine?

Interested as to why a VW specialist would want you take it for a compression test instead of doing it themselves?
Could well be a leaking injector as @Dellmassive said. When you stop the engine it may well be draining fuel into the cylinder which then gets discharged and burnt in the exhaust system when you re-start causing the smoke. If this is the case there will definitely be some fuel in the engine oil and it will be washing oil from the affected cylinder and diluting the oil to the rest of the engine.
My advice is not to drive until you have a solution.

 

[Matt maz]

Interested as to why a VW specialist would want you take it for a compression test instead of doing it themselves?
Could well be a leaking injector as @Dellmassive said. When you stop the engine it may well be draining fuel into the cylinder which then gets discharged and burnt in the exhaust system when you re-start causing the smoke. If this is the case there will definitely be some fuel in the engine oil and it will be washing oil from the affected cylinder and diluting the oil to the rest of the engine.
My advice is not to drive until you have a solution.

Apparently the equipment they have was not able to to go deep enough to perform the test?!? Safe to say I’ve lost confidence in this garage.
Van is currently collecting dust on the drive until it goes into VW on Wednesday. Fingers crossed it’s not a new engine, again quoted by the VW specialist. ¯\_(ツ)_/¯

 

[DXX]

Apparently the equipment they have was not able to to go deep enough to perform the test?!? Safe to say I’ve lost confidence in this garage.
Van is currently collecting dust on the drive until it goes into VW on Wednesday. Fingers crossed it’s not a new engine, again quoted by the VW specialist. *

‘A new engine’, that’ll save any expensive diagnostics then, you’ve just got to love the way VW operate.

 

[DaveD]

‘A new engine’, that’ll save any expensive diagnostics then, you’ve just got to love the way VW operate.

I suspect they might be trying harder to resolve it without talk of a new engine if it was a warranty claim.

 

[Unimog]

Matt, can you update us on your engine issue, and do you know which engine variant you have CXHA or CXFA?

 

[Matt maz]

Matt, can you update us on your engine issue, and do you know which engine variant you have CXHA or CXFA?

It’s the CXHA.
Same conclusion from the VW garage, new engine! Have said that a compression test would just be a waste of my money. They couldn’t give me a definitive explanation as to why the engine has failed but suggest it could be the grade of oil I was using. (All service parts and oil are from TPS). My invoices for the parts are not proof enough apparently.
VW UK said they may offer £500 towards the cost of a replacement £7k engine and the garage undertaking the work will give me a discount (how much this is I have not been told yet).

 

[mmi]

It’s got all the symptoms of the biturbo EGR problems

What symptoms exactly?

 

[DaveD]

It’s the CXHA.
Same conclusion from the VW garage, new engine! Have said that a compression test would just be a waste of my money. They couldn’t give me a definitive explanation as to why the engine has failed but suggest it could be the grade of oil I was using. (All service parts and oil are from TPS). My invoices for the parts are not proof enough apparently.
VW UK said they may offer £500 towards the cost of a replacement £7k engine and the garage undertaking the work will give me a discount (how much this is I have not been told yet).

If it can't be diagnosed via the OBD port they're not interested or possibly not competent to diagnose the problem.
I don't think either garage know what is actually wrong with it so can't tell you why it is running rough, it's easier and more profitable for them if you have a new engine at £7K plus VAT plus fitting, less an unknown discount that might amount to nothing and a possible £500 from VW that might turn out to be nothing.
It could turn into a £10K job, I'd have to be certain that it was necessary and that it would resolve the issue before agreeing to it.

 

[DXX]

A compression test shouldn’t take much more than 40 minutes labour and zero consumables.
If there is low pressure on a cylinder you can determine if caused by leaking piston rings or valves by adding 20-30mL of engine oil into the cylinder with a syringe and repeating the test.
If the pressure has increased over the first test without the oil it is the piston rings.
I’d be asking for a compression test and want to witness it.

 

[Ozi]

If the only other option is commit to a new engine, a compression test feels like the only logical option at this stage. They clearly haven’t identified the issues fully yet, so seems very premature to suggest a new engine.

 

[Unimog]

I would be inclined to take your van to an independent diesel specialist, not just a local garage. They will have the necessary test equipment and knowledge. I suspect Vw won’t want to get involved with stripping down engines.

 

[Lukefx]

Hi all, I’ve just recently starting having issues with my 2018 T6 (150ps). There’s a lot of engine vibration on idle up to 1500rpm, a bad smell of unburnt diesel and a lot of white smoke for around 10mins until it’s warmed up. It’s covered 105k (miles) but sits on the motorway and doesn’t really cover short journeys (hence the high milage for the age)
It’s got all the symptoms of the biturbo EGR problems but I can’t find anyone that’s had this problem with this engine. Has anyone had this issue?
No warning lights on. Fuel filter/ oil filter changed. No sludge in the oil filler and old oil looks free of debris. Engine runs like garbage until it warms up then the vibrations are intermittent. Any ideas?

Jumping on an old thread here while my wagon is in bits! How did this end Matt?