[m.rk77]

I had some exhaust smell coming in through the vents so I popped the hooded to have a look around the engine.

While looking around I noticed that the smell was very intense around the turbos so I had a closer look with a flashlight and I noticed a lot of oil was leaking out around the turbo.

I took it to the shop and they replaced the turbos.


This is a hazardous and poisonous problem that can be hard to detect and fix...

I will post a picture where I will point out the spots where oil was and is leaking! I cant figure out where the exhaust smell is coming from but I know for sure it is coming from the left side of the engine around the turbos... I don't know why it is not constant, it only smells from time to time, usually at low RPM under 2500.


here is a picture of the 335d engine with description of the problem areas that I discovered.

[Dave_3]

Have you taken it back to your dealer and asked them ?

D.

[dxb335d]

white smoke?

when you take oil filler cap off and the engine is hot, smoke will come out.

Have you noticed a lack in performance at all?


You have had both turbos replaced but still exhaust gas is leaking from the manifold? maybe the manifold is distorted or cracked somewhere?!




Carlos

[m.rk77]

the thing is that the exhaust only leaks sometimes not all of the time and today I noticed oil leaking out in the circle on the right in the picture above.

They have replaced the turbos and now this.

[m.rk77]

also I noticed that the engine was feeling weaker before the turbos were replaced. It was back to normal afterwards but now it feels a little weaker again.

[dxb335d]

So when you say ''exhaust leaking'' you mean exhaust gas? or oil leak?

[m.rk77]

both.
Oil was leaking around turbos. Turbos changed, no more leak there. BUT now oil is leaking in the circle on the right in the pic above.

Exhaust gas leaks from time to time. Very strong smell in the engine compartment which flows inside the cabin if vents are opened. This happens approx every 2 days...

[quattrogmbh]

I seem to have an exhaust gas smell under the bonnet in the location you describe, but nothing entering the cabin and no visible oil leaks. I wonder whether the exhaust gas is recirculated at idle?

[m.rk77]

This is what the problem was: there is a pipe around the turbos which is responsible for oil return into the engine. Basically oil is pushed out of the engine due to high compression and the powerful turbos, and this pipe is supposed to return the oil into the engine.

This "pipe" was not connected properly and a piece was missing, and therefore oil was slowly but surely leaking into the turbos... From time to time this oil would burn up inside the turbo pipes which is the cause of the bad exhaust smell around the turbo area. (see picture at the top)

If you have this exhaust smell then you should take it to the shop to ensure that this "pipe" is connected properly. If you see any oil around the area then you definitely have this problem.

the turbos on the 335d are very complicated... The turbos are the reason why this engine is so powerful.

[quattrogmbh]

So was it a diesel exhaust gas smell, or a smell of burning oil?

I have no sign of any oil leaks. The turbo oiler unions are perfectly clean and I don't smell burning oil, simply a slight whiff of diesel exhaust.

now we just need someone to say "But diesel is oil!!!" ;-)

[dxb335d]

Originally Posted by quattrogmbh

now we just need someone to say "But diesel is oil!!!" ;-)

Oh right, is that why Derv's are called ''oil burners''

[quattrogmbh]

most probably ;-)
Would someone else with a 335D "sniff" around the turbos with the engine running and advise if they can detect a "whiff" of exhaust gas -- Ta.

[roofer]

This "pipe" was not connected properly and a piece was missing, and therefore oil was slowly but surely leaking into the turbos... From time to time this oil would burn up inside the turbo pipes which is the cause of the bad exhaust smell around the turbo area.

Something not right here, where's the smoke from burning oil?
Turbo gasket with exhaust must be leaking, which you would hear?

[m.rk77]

It was more of a heavy diesel exhaust/oil smell, a little stronger then the smell you get when you open the oil cap on top of the engine.

I never saw any smoke!! But you can definitely smell it when you open the hood and sometimes you can smell it just by standing next to the car.

I did not have any oil leaking at the turbo unions, it was leaking in a spot thats not visible from the top down... But if it is leaking you should be able to see some oil if you use a flashlight.

NOTE: if you drive is smooth you might never get the oil leak and the damage might take years to show up. Therefore I suggest that you step on the gas a little harder and if possible take it on the higher all the way to max speed of 270. (do it in Germany or DON'T GET CAUGHT!

Originally Posted by quattrogmbh

So was it a diesel exhaust gas smell, or a smell of burning oil?

I have no sign of any oil leaks. The turbo oiler unions are perfectly clean and I don't smell burning oil, simply a slight whiff of diesel exhaust.

now we just need someone to say "But diesel is oil!!!" ;-)

[m.rk77]

some more pictures of the oil leak http://www.e90post.com/forums/showth...ght=bmw+diesel

[quattrogmbh]

Thanks. Mine certainly isnt a burning oil smell. As soon as the engine is switched off, the smell goes, hence my assertion that it could well be Exhaust Gas Recirc or something similar.

Would still be interested if others get a whiff of Diesel exhaust smell from the engine compartment at idle.

Thanks.

[m.rk77]

quattrogmbh: there shoul NOT be any exhaust smell around the engine because:

1. this would be sucked into the passenger cabin which is bad for your health and it has CO2 (carbon monoxide) which is a colorless odorless poison that can put you to sleep and at high levels it can cause death.

2. this is pollution, all exhaust has to be filtered by the exhaust system... If everything is connected and sealed properly like it should be then you should not smell anything around the engine.


You can buy a simple carbon monoxide alarm and place it on the floor on the passenger side. If it goes off (like mine did) then you definitely have an exhaust leak by the engine.

[dxb335d]

Thinkng about it, it stinks around my engine too sometimes. No sign of oil tho... Just stinks of very hot engine.

[m.rk77]

to a small extent that is acceptable and normal BUT it is not normal to smell it while standing next to your car and especially if you smell it more while the engine is running there might be a problem. But to an extent it also matters how sensitive your nose is...

Originally Posted by dxb335d

Thinkng about it, it stinks around my engine too sometimes. No sign of oil tho... Just stinks of very hot engine.

[jwbmw]

Originally Posted by dxb335d

Thinkng about it, it stinks around my engine too sometimes. No sign of oil tho... Just stinks of very hot engine.

Try washing your jock strap

[beemerbird]

Originally Posted by jwbmw

Try washing your jock strap

Nice one Jason


So then, we're all now going to be 'sniffing' away under our bonnets for nasty whiffs.

[dxb335d]

LOL