Diesel Expert opinions required

[flango]

Hi Guys

Need some help and advice if anyone has come across this before, firstly it's a BMW engine 3.0 litre diesel in a E60 525 M sport. It has had the DPF removal by Eco-Tune Scotland see HERE It also has EGR delete. Recently upon accelaration and on overun there is massive amounts of blue smoke and I mean massive.

Problem is excessive oil getting into the exhaust, at first we thought it was the turbo exhaust seal as this is quite a common problem after a dpf delete and the turbo did sound a bit noisy, so removed the turbo and sent away for exam and report, report comes back turbo in good health a little wear but consistent witt mileage 100k anyway whilst it's off that is being refurbed. The turbo specialist reckons the cause of the problem is not the turbo exhaust seal but back pressure caused by something else, we have checked the usual suspects crankcase breather, turbo oil drain, have changed oils and filters regularly so it's not neglect. The dpf delete pipe is saturated with oil but we are sure it is not passing the turbo exhaust seal.

What we don't want to do is put the refurbed turbo back on and still have the same issue, whilst it is off we would like to find the root cause but are fast running out of ideas as what could be causing back pressure or is it something else?

Also anyone else used eco-tune Scotland and have any comments?

All help and advice welcome

TIA

 

[BlackC55]

Rings?

Maybe worth whipping the head off?

 

[Vlad]

You say you looked at the crank case breather (im assuming the one on the top of the engine towards the back), but did you actually replace the filter?

If these are blocked they create massive amounts of blue smoke

 

[flango]

Def not the rings well not two months ago anyway head was off less than 2000 miles ago and head and block components like new car only ever been run on v power diesel

Crankcase breather filter changed everytime it had an oil change current filter like new.

There was a significant ammount of oil in the turbo and we expected the piston seal to have gone but this turbo has 2 seals and both are fine. The other significant oil source was in the dpf replacement pipe as illustrated.

The two common factors prior to this occuring were castrol changing oil spec from slx to slx professional and the dpf delete

This is really baffling

 

[Dieselman]

Any oil in the exhaust manifold? Have you tried running it with the manifold or turbo off to see which cylinder(s) are smoking.

Has this car been chipped, if so, I go with rings having overheated and lost temper.

To check if it's the rings, perform a compression test, to check if the oil is exiting the breather make up a temporary catch can out of a plastic bottle.

 

[flango]

Any oil in the exhaust manifold? Have you tried running it with the manifold or turbo off to see which cylinder(s) are smoking.

Has this car been chipped, if so, I go with rings having overheated and lost temper.

To check if it's the rings, perform a compression test, to check if the oil is exiting the breather make up a temporary catch can out of a plastic bottle.

I had hoped you would see this Compression test perfect and no oil exiting breather into temporary catch can, no oil in exhaust manifold tried those tests already, anything else you can point me in the direction of

Thanks for the help

 

[Dieselman]

It has to be the turbo if there is no oil in the exhaust manifold. Did you check the turbine housing for oil deposits.

Is the turbo oil return running freely?

 

[flango]

It has to be the turbo if there is no oil in the exhaust manifold. Did you check the turbine housing for oil deposits.

Is the turbo oil return running freely?

There is slight oil in the turbine housing but nothing like the quantity I would expect to be causing this type of problem, The turbo refurber who is AET also said they think there is another cause, turbo oil return running freely although there is as connector at the block which we still have to remove to see if it is clear

 

[flango]

Just to update the thread, initial diagnosis correct it was the turbo exhaust seal, refurbed turbo now back on car and running like a dream with no smoke at all. Thanks to all for the comments.