# 335d - Soot around turbos



## ratherBeDriving (Apr 25, 2012)

New member and a first time diesel owner here. I come from a 2008 328i.

I posted this topic on another forum. The diesel community in this forum seems to be more active, so I'm posting this topic again. My apologies for those who follow both forums. Original thread can be found here. 

335d is an awesome car! I tried to convince myself to get the tried and true 335i however after a few test drives, I got addicted to the diesel's torque and it has been a blast so far. I would like to keep this car for as long as I can. So I would appreciate your help to diagnose, what I think is soot build up around my turbos. Car is new and has a little over 5500 miles, I drive it hard.

Following is where I see what seems to be splashed mix of soot and some liquid (sorry for the quality of the pictures, this is a very though to capture area with the equipment I have available):










Here you can see it a bit closer:










Even closer:










You can see the same stuff sprayed on a clamp near the actuator between the turbos:










Again the same area:










This stuff doesn't look like oil to me, however I would like to know what you think. I would also appreciate if you let me know whether you observe a similar build up around this area.

Thanks!


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## Flyingman (Sep 13, 2009)

To be honest I haven't really looked that closely under my hood to detect anything like this.

It almost looks like overspray perhaps from under coating process, a bit sloppy though.

It doesn't look like oil at all, more like paint splatter.

Can you get a swab of it, say with a Q-Tip or something like that? If it's soot it should come off rather easily. If overspray it ain't going nowhere.

You seeing much evidence of soot at the tail pipe?


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## ratherBeDriving (Apr 25, 2012)

Flyingman said:


> To be honest I haven't really looked that closely under my hood to detect anything like this.
> 
> It almost looks like overspray perhaps from under coating process, a bit sloppy though.
> 
> ...


Great points. Yes it does look as if it is paint.

However it is not over spray of anything, this area was squeaky clean when the car was brand new with 8 miles. And it is not coming off. I check this area about every 1K mile and it is slowly building up. I see this stuff all over the exhaust side of the engine.

Tail pipe is ridiculously clean. Much cleaner than my 08 328i.


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## Flyingman (Sep 13, 2009)

Try cleaning it off with something. If it is loose and comes off with water or wiping, it's most likely soot.

If it's soot you have some sort of exhaust leak. Someone else on here has posted about a leaking turbo exhaust, sooting up under the hood.


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## cssnms (Jan 24, 2011)

Or better yet, take it to the dealer, that's why you have a warranty. :dunno:


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## Snipe656 (Oct 22, 2009)

cssnms said:


> Or better yet, take it to the dealer, that's why you have a warranty. :dunno:


That is silly thinking right there.


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## ductman (Dec 17, 2011)

ratherBeDriving said:


> New member and a first time diesel owner here. I come from a 2008 328i.
> 
> I posted this topic on another forum. The diesel community in this forum seems to be more active, so I'm posting this topic again. My apologies for those who follow both forums. Original thread can be found here.
> 
> ...


Noticed the same on mine just not as much as yours, maybe it had to do with my leaking EGR valve if it is indeed soot, but the valve is on the opposite side of the engine.


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## F32Fleet (Jul 14, 2010)

I wonder if this happens when the car is turns off in the middle of DPF regen. Probably not "a problem" IMO


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## Snipe656 (Oct 22, 2009)

Does a regen ever vent something to atmosphere in te engine compartment? I'd think that is a major emissions "no no" and would imagine soot under the hood is a sign of raw exhaust venting to atmosphere.


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## serge1 (Jan 6, 2012)

I had posted this pic in the "Diesel Smell" thread.
On passenger side of the engine, I do see some kind of buildup, as if exhaust is leaking. Could explain ocasional diesel smell, despite EGR valve being in seemingly normal state.


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## jashearer (Nov 9, 2011)

This past winter I had a similar build-up on a white 5 gallon bucket that was about 2 feet from the exhaust exit of my diesel truck. It doesn't have any doc/dpf so I assumed it was sooty build up from initial starts. It looks exactly like your picture and would not come off when I rubbed it. Reminds me of paint overspray.

I'll check my x5d tonight and see if I have similar issue there.

Jay


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## Snipe656 (Oct 22, 2009)

jashearer said:


> This past winter I had a similar build-up on a white 5 gallon bucket that was about 2 feet from the exhaust exit of my diesel truck. It doesn't have any doc/dpf so I assumed it was sooty build up from initial starts. It looks exactly like your picture and would not come off when I rubbed it. Reminds me of paint overspray.


My old Mercedes does it and did it to my garage door when I failed to open it up before leaving the car running. For a long time I had a lot of bags of mulch in my driveway not too far from where I park the truck. Those bags had it too from me leaving the truck idling out there most mornings. I have nothing from the exhaust of the BMW but would expect nothing from it. I have not paid this close attention to the engine bay before.


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## cssnms (Jan 24, 2011)

I wonder if this is blow-by from the crank case ventilation system?


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## serge1 (Jan 6, 2012)

cssnms said:


> I wonder if this is blow-by from the crank case ventilation system?


Shouln't exhaust pipe be the only escape for any gasses out of the engine?
First time I hear of crank case ventilation..


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## Snipe656 (Oct 22, 2009)

Crank case ventilation on my other cars goes back into the intake stream in one manner or another. Never is vented to atmosphere in my experience.


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## jashearer (Nov 9, 2011)

Snipe656 said:


> Crank case ventilation on my other cars goes back into the intake stream in one manner or another. Never is vented to atmosphere in my experience.


:thumbup: it used to be vented to atmosphere using venturi pipes, EPA decided that was a bad idea quite a while ago, and now the vacuum created in the fresh air intake acts to vent the crankcase. Of course this means oil vapor and blow by now enter the intake post air filter, but that's another point.

Jay


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## cssnms (Jan 24, 2011)

Not sure, just a guess as to the source. I asssume our engines have a breather tube and or crank case vent bottle which catches the oil no? I've heard/read enough reports where a vent tube may spit some oil or the oil vent bottle mucking things up.


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## Snipe656 (Oct 22, 2009)

cssnms said:


> Not sure, just a guess as to the source. I asssume our engines have a breather tube and or crank case vent bottle which catches the oil no? I've heard/read enough reports where a vent tube may spit some oil or the oil vent bottle mucking things up.


I do not know how the setup is on these cars specifically but I think it is real safe to assume that exhaust venting to atmosphere is not by design since the government environmental bodies do not like such things. I'd imagine what is shown in those pictures is cooked on soot from vented exhaust. "Cooked on" in that it will not just wipe off by hand any more.


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## cssnms (Jan 24, 2011)

Snipe656 said:


> I do not know how the setup is on these cars specifically but I think it is real safe to assume that exhaust venting to atmosphere is not by design since the government environmental bodies do not like such things. I'd imagine what is shown in those pictures is cooked on soot from vented exhaust. "Cooked on" in that it will not just wipe off by hand any more.


I am not talking about exhaust gases venting, but rather a breather tube for the crankcase to release pressure build-up. The crankcase must have a breather tube.


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## Snipe656 (Oct 22, 2009)

cssnms said:


> I am not talking about exhaust gases venting, but rather a breather tube for the crankcase to release pressure build-up. The crankcase must have a breather tube.


Every modern car I have owned has these and they all tie back into the intake track one way or another. None of them vent to atmosphere. I am not 100% sure on the old Mercedes but I think the only car I own that vents this to atmosphere is my 1967 Mustang and that is via an aftermarket method so not even sure from the factory if they vented to atmosphere or not back then.


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