Exhaust problem

[optimistique1]

Hi All, when I start the car up from a cold start there's always a huge plume of smoke that comes from the exhaust now, more that there used to be.

Once the car is running the exhaust fumes seem to go back to normal, although I am sure I can here very faint rattling...

Do I need a new exhaust and if so, has anyone a rough idea on the cost to get a new one fitted?

 

[tintoverano]

this is not an exhaust problem

try to check the color of the smoke first

 

[Boltz]

Post a clip up of the smoke when you start the car up, what model Zed is it?

 

[optimistique1]

Ok the colour is a blue tint smoke and here's a clip of me cold starting the card (E89 2.0i)...
Also checked oil and coolant and both full and ok..
See video link below:

https://1drv.ms/v/s!AhhkyEkd0PFJhq8Kz1IIM6lzFAMahQ

 

[Smartbear]

If you have blue smoke from the exhaust it’s either engine damage/wear or turbo seals, how many miles has the car covered? :?
Rob

 

[optimistique1]

It's done just over 71K or thereabouts...
Are those issues you mentioned serious about the seals etc?

 

[TitanTim]

What mileage has the car done?

Seems the turbos tend to go on the N20 engines as early 30k miles, plenty of info on the various 3 series forums.

You might be lucky and its a dodgy oil inlet pipe.

Tim.

 

[Smartbear]

It's done just over 71K or thereabouts...
Are those issues you mentioned serious about the seals etc?

If it’s turbo seals then you should be able to get the turbo reconditioned, if it’s from engine oil burnt by the engine it needs professional diagnosis to pinpoint where the oil’s entering the combustion chambers.
I’m surprised the engine oil level hasn’t dropped if it’s creating smoke like that?
Rob

 

[Smartbear]

What mileage has the car done?

Seems the turbos tend to go on the N20 engines as early 30k miles, plenty of info on the various 3 series forums.

You might be lucky and its a dodgy oil inlet pipe.

Tim.

I’ve never once read of a failed n20 turbo on here, they’ve been around since 2011 so would have thought we’d have seen a few by now?
Have you got any links for all these failures you mentioned Tim?
Rob

 

[optimistique1]

I'm trying to get the car booked into to my local indie specialist and pray it's not going to break the bank balance...
I don't do a lot of miles in the car, usually just short journeys, shops, friends, relatives etc...

 

[TitanTim]

What mileage has the car done?

Seems the turbos tend to go on the N20 engines as early 30k miles, plenty of info on the various 3 series forums.

You might be lucky and its a dodgy oil inlet pipe.

Tim.

I’ve never once read of a failed n20 turbo on here, they’ve been around since 2011 so would have thought we’d have seen a few by now?
Have you got any links for all these failures you mentioned Tim?
Rob

Probably down to the ratio of ownership and minority of Z4 owners

https://f30.bimmerpost.com/forums/showthread.php?t=965952&highlight=white+smoke

https://f30.bimmerpost.com/forums/showthread.php?t=1155261

Tim.

 

[Anonymous]

It’s a known fault on some N20 engines..oil from the turbo oil feed pools inside the turbo after shut down then generates loads of blue smoke..

Later version of oil feed pipe with a non return valve is recommended fix.

https://bmwtechnician.com/2016/05/13/n20-oil-feed-line-update/ Refers

 

[optimistique1]

It’s a known fault on some N20 engines..oil from the turbo oil feed pools inside the turbo after shut down then generates loads of blue smoke..

Later version of oil feed pipe with a non return valve is recommended fix.

https://bmwtechnician.com/2016/05/13/n20-oil-feed-line-update/ Refers

Is this the most likely cause of the problem and how expensive of a fix is it?

 

[Anonymous]

Like any diagnosis done remotely and with very limited data it’s limited now in it’s certainty...

The pipe I think is around £50...

You need your build date / engine number and compare with when they installed it in production..

Obviously if your car is pre change then it heightens the probability if it’s after then it’s not this solution..

 

[Smartbear]

Like any diagnosis done remotely and with very limited data it’s limited now in it’s certainty...

The pipe I think is around £50...

You need your build date / engine number and compare with when they installed it in production..

Obviously if your car is pre change then it heightens the probability if it’s after then it’s not this solution..

I think the modded oil feed pipe was introduced in 2015 sometime :?
Rob

 

[optimistique1]

Thanks again for all the advice I’m going to get it booked in for next week hopefully.
I assume it’s safer not to drive in the meantime?

 

[Anonymous]

Actually it’s not a major issue on a short term basis..it only happens after shutdown and doesn’t affect normal operations..the embarrassing bit is the smoke on start up...

Of course that’s assuming my diagnosis is correct...

Best to get it checked out with some one who knows N20 engines..

 

[Boltz]

OP, did you get this problem sorted and if so what was it?

 

[Marbeck64]

Sounds like it could be the valve stem seals. Oil will leak by them after running a while and after sitting for a while, on start up it gets burnt off. Hence the blue smoke on start up.

 

[Anonymous]

Sounds like it could be the valve stem seals. Oil will leak by them after running a while and after sitting for a while, on start up it gets burnt off. Hence the blue smoke on start up.

Very unlikely...common in older designs but unheard of on the N20..I give 98% probability that it was the turbo non return oil feed pipe..