# Exhaust smell inside car! What is this part? A lot of soot!



## crom1 (Jul 17, 2013)

I have troubles with exhaust smell in my car when it's idling. Exhaust pipe troubles? Recently changed the turbo.

I took of the cover in my engine and instantly found this sooted part. What is it?

Thanks.

See attachment.


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## roadkillrob (Aug 11, 2006)

What year and what engine is that?


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## crom1 (Jul 17, 2013)

Sorry..

E90 320D 2006mod, M47TU2D20 engine. European car.


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## floydarogers (Oct 11, 2010)

According to http://www.realoem.com/bmw/showparts.do?model=VC32&mospid=48480&btnr=11_3717&hg=11&fg=40 it's the throttle.
Don't know why it's carboned up - might expect it of the EGR (which is the s-bend aparatus going down to the EGR cooler.


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## Blackedout335i (May 1, 2013)

I had a similar problem with my 07 335i, the cabin would smell like exhaust. Started snooping around starting with the downpipes and found that I had a leak where the downpipes meet with the mid exhaust. You could have a leak anywhere when not moving, the smell creeps into your cabin.
Make sure you pipes are cool, and start your engine get under it and feel for any air escaping from where the pipes join. you're almost certain to find the issue. 
PS. Clean that engine.


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## BB_cuda (Nov 8, 2011)

There is some black stuff right there at the throttle body flap axis. See the stuff on the spring. I'm an ex smoker and glad i quit 25 years ago but a good use for a lit cigarette put close to suspected leak spots will possibly show leak points. I would start at that soot spot shown in the photo. I agree with Floyd. The EGR injection point is downstream of the throttle body. You may need to get a buddy to moderately increase throttle from the driver's seat while you are hunting with the cig. Good luck.


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## CALWATERBOY (Aug 26, 2009)

crom1 said:


> I have troubles with exhaust smell in my car when it's idling. Exhaust pipe troubles? Recently changed the turbo.
> 
> I took of the cover in my engine and instantly found this sooted part. What is it?


I have just discovered that BMW turbos, maybe others too, are operated by exhaust gas!!!!!

As you've just replaced the turbos and exhaust smell appears to be coincident, well.....mmmmm.....

Hey this is no diesel forum! Have no idea what that part is. RealOEM drawing, your model?

.


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## crom1 (Jul 17, 2013)

Thanks for all your input, guys.  Looking for leaks and loose clamps now!

While I'm at it, I'm gonna clean the engine as well, but I must admit that I'm a little bit nervous of pouring alot of water in there... I'm generally very strict with keeping my car clean, but not under the hood. Perhaps someone can tell me a bit about how to do it "correctly"? What to cover up? Hot water? Cold water?



PS: Mod: Please move thread to diesel forum.


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## BiHoTTo115 (Aug 6, 2012)

crom1 said:


> Thanks for all your input, guys.  Looking for leaks and loose clamps now!
> 
> While I'm at it, I'm gonna clean the engine as well, but I must admit that I'm a little bit nervous of pouring alot of water in there... I'm generally very strict with keeping my car clean, but not under the hood. Perhaps someone can tell me a bit about how to do it "correctly"? What to cover up? Hot water? Cold water?
> 
> PS: Mod: Please move thread to diesel forum.


http://www.detailedimage.com/Ask-a-Pro/how-to-detail-your-engine-bay/

Here you go. I suggest using a good degreaser and scrubbing the gunk away on everything you see with a brush before shooting the place up with water. Powerwashers work well.


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## Blackedout335i (May 1, 2013)

There are tones of engine cleaning tutorials on YouTube, no need to run a hose under the hood scub brushes and degreasers will do just fine with some finesse.


Sent from BimmerApp mobile app


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## roadkillrob (Aug 11, 2006)

That much oily soot on it would indicate that the throttle shaft is leaking, since it is a turbo, there is a fair bit of pressure there, so it doesn't take much if it is not sealed. The concerning part is he amount of oily residue as that came from inside the intake, meaning a lot of oil in the intake and the only place that can come from would be the turbo seals leaking. If this was like this before you replaced the turbo it would make sense if the old turbo was leaking oil, then you may just need to fix the seal issue on the throttle shaft, unfortunately it doesn't appear you can buy anything but the complete assembly for 400 bucks.

Guessing the exhaust smell is more likely a leak either at the manifold or downpipe and that will smell up the car.

Rob


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## finnbmw (Jul 6, 2008)

I bet your EGR cooler is cracked and leaking soot and exhaust gases. Do a search for "EGR cooler cracked" or similar.

Pretty common problem with the BMW diesels


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## floydarogers (Oct 11, 2010)

finnbmw said:


> I bet your EGR cooler is cracked and leaking soot and exhaust gases. Do a search for "EGR cooler cracked" or similar.
> 
> Pretty common problem with the BMW diesels


You didn't look closely enough at the pic. The EGR cooler and line is pristine, and the soot is clearly on the throttle assembly.


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## crom1 (Jul 17, 2013)

floydarogers said:


> You didn't look closely enough at the pic. The EGR cooler and line is pristine, and the soot is clearly on the throttle assembly.


I agree with you.

Can anyone shed some light on what the "throttle" really does here? I have searched around the web a bit and haven't seen anyone mention having problems with residue on this part. I think also the part is located at a different place in the compartment as i can't localise it on all the pictures I've seen.

roadkillrob: your thoughts regarding the turbo makes sense. I have now a completely new turbo installed and i will try to clean the throttle shaft up as much as possible and re-check for residue after some miles.


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## d geek (Nov 26, 2008)

crom1 said:


> I agree with you.
> 
> Can anyone shed some light on what the "throttle" really does here? I have searched around the web a bit and haven't seen anyone mention having problems with residue on this part. I think also the part is located at a different place in the compartment as i can't localise it on all the pictures I've seen...


I think the "throttle" is an anti-shudder valve. These are used to shut the engine down smoothly by cutting off air immediately on shutdown.

Oil could be from the turbo or from PCV system.

I'd remove the intercooler inlet and outlet hoses and check for oil collecting there.


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## floydarogers (Oct 11, 2010)

d geek said:


> I think the "throttle" is an anti-shudder valve. These are used to shut the engine down smoothly by cutting off air immediately on shutdown.


Also seems to be related to apportioning air mixture EGR versus "clean" air.


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## Hoooper (Jun 17, 2013)

roadkillrob said:


> That much oily soot on it would indicate that the throttle shaft is leaking, since it is a turbo, there is a fair bit of pressure there, so it doesn't take much if it is not sealed. The concerning part is he amount of oily residue as that came from inside the intake, meaning a lot of oil in the intake and the only place that can come from would be the turbo seals leaking. If this was like this before you replaced the turbo it would make sense if the old turbo was leaking oil, then you may just need to fix the seal issue on the throttle shaft, unfortunately it doesn't appear you can buy anything but the complete assembly for 400 bucks.


or the other, more obvious and common place for oil to come from, the PCV


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## d geek (Nov 26, 2008)

floydarogers said:


> Also seems to be related to apportioning air mixture EGR versus "clean" air.


I was wondering about that, but the EGR inlet appears to be downstream of the valve- so I don't think that's the case.


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## Hoooper (Jun 17, 2013)

d geek said:


> I was wondering about that, but the EGR inlet appears to be downstream of the valve- so I don't think that's the case.


if that throttle valve closes, the engine should pull more recirculated air when the EGR is opened, so it could possibly be used for that effect. Anyone with a Bavtech tool should be able to check into that. Mine wont be up and running until tomorrow.


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## fdriller9 (Oct 19, 2006)

CALWATERBOY said:


> I have just discovered that BMW turbos, maybe others too, are operated by exhaust gas!!!!!
> 
> As you've just replaced the turbos and exhaust smell appears to be coincident, well.....mmmmm.....
> 
> ...


lol all turbos are operated by exhaust gas. Superchargers are belt driven, hence little to no lag.


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## BB_cuda (Nov 8, 2011)

fdriller, Cal is super sarcastic but quite knowledgible on many topics. He has a "different" brand of humor [which i find to be funny]. His point is you just disturbed something and now a new problem exists. Go hunt there first. He runs a E93 N54 turbo gas burner. This thread was over in the "mainstream" 3 series section when he wrote but then it was moved over here with us where it belongs. Cal wrote a killer DIY on converting E9X over to M3 suspension (but not full 100%). He runs meth/water injection, or he once did.

Early in this thread, we didn't know the OP was running a 320D/European market.

@crom1, did the throttle assy get removed during the turbo work [EGR valve cleaning would require this]? What was wrong with prior turbo? Perhaps if it had low to no boost, the new turbo is now producing legit pressure to now blow out of that throttle shaft seal. Go get a buddy to rev the engine and put a smoke source [lit cigarette works like a champ] by the oiled up spring/shaft area. that is a quick and easy thing to do before digging down into turbo area where its so much more cramped.

my 2c


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## GeoX750Li (Apr 6, 2013)

Cal's post was hilarious! The "maybe others too" serves as both the tell and the punch line.


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## d geek (Nov 26, 2008)

realoem.com shows the egr valve being the part that the egr plumbing goes to. A vacuum actuator is attached to the other side away from the inlet. This controls exhaust gas into the intake:
http://www.realoem.com/bmw/showparts.do?model=VC31&mospid=48480&btnr=11_3717&hg=11&fg=40

The device with the oil is shown as a "throttle". As we all know, diesels run on max air all the time and adjusts fueling- there is no throttle to control air in normal operation. I'm pretty sure this is just to stop the engine smoothly.


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## F32Fleet (Jul 14, 2010)

d geek said:


> realoem.com shows the egr valve being the part that the egr plumbing goes to. A vacuum actuator is attached to the other side away from the inlet. This controls exhaust gas into the intake:
> http://www.realoem.com/bmw/showparts.do?model=VC31&mospid=48480&btnr=11_3717&hg=11&fg=40
> 
> The device with the oil is shown as a "throttle". As we all know, diesels run on max air all the time and adjusts fueling- there is no throttle to control air in normal operation. I'm pretty sure this is just to stop the engine smoothly.


And prevent runaway.


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## Hoooper (Jun 17, 2013)

d geek said:


> realoem.com shows the egr valve being the part that the egr plumbing goes to. A vacuum actuator is attached to the other side away from the inlet. This controls exhaust gas into the intake:
> http://www.realoem.com/bmw/showparts.do?model=VC31&mospid=48480&btnr=11_3717&hg=11&fg=40
> 
> The device with the oil is shown as a "throttle". As we all know, diesels run on max air all the time and adjusts fueling- there is no throttle to control air in normal operation. I'm pretty sure this is just to stop the engine smoothly.


point was that the throttle could also be used to force the engine to pull more through the EGR than it would with that throttle being fully open. If the engine is not in boost then closing down that throttle a bit would force the engine to pull from the EGR more. Not sure if/how that would work under boost though


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## d geek (Nov 26, 2008)

Hoooper said:


> point was that the throttle could also be used to force the engine to pull more through the EGR than it would with that throttle being fully open. If the engine is not in boost then closing down that throttle a bit would force the engine to pull from the EGR more. Not sure if/how that would work under boost though


You always want max air available for a diesel, so you'd never put a restriction in there. The EGR rate can be tighly controlledl with the vacuum actuated valve.


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## Hoooper (Jun 17, 2013)

I think youre missing the point. If the EGR is fully open and you still arent getting enough recirc, the only solution would be to draw more vacuum which would cause it to pull through the EGR more, and the only way to do that would be to shut the valve down some. Not saying this IS a use for that valve, but only a possibility. If someone has actual information on the ECU coding for the throttle control that would answer the question.


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## d geek (Nov 26, 2008)

BMWTurboDzl said:


> And prevent runaway.


I'm not clear on how it could be set up to accomplish this without human intervention. On VW, the ASV (anti-shudder valve) is normally open. and uses residual vacuum to temporarily close the valve when the engine is shut down. After the vacuum is dissipated, then the valve opens back up for the next start up.

It is true that you can use the ASV to kill the engine in a runaway condition, but you'd need to pop open the hood, and reach in there while the engine is running close to redline to manually close the valve. It would definitely be effective, but you need to be confident in what you're doing and have nerves of steel.


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## Hoooper (Jun 17, 2013)

does runaway (not in the Toyota sense, but the typical diesel sense) even apply to computer controlled diesels anyway? Seems to me it wouldnt be possible to get runaway if the computer is controlling fuel pressure and injectors. If the ECU says no fuel, then no fuel is what the engine gets. On the other hand, it wouldnt need to be human intervention. That throttle is electronically controlled so if the computer senses a runaway it could shut the valve. Or it could just cut the fuel :dunno:


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## 335dFan (Nov 8, 2012)

Hoooper said:


> does runaway (not in the Toyota sense, but the typical diesel sense) even apply to computer controlled diesels anyway? Seems to me it wouldnt be possible to get runaway if the computer is controlling fuel pressure and injectors. If the ECU says no fuel, then no fuel is what the engine gets. On the other hand, it wouldnt need to be human intervention. That throttle is electronically controlled so if the computer senses a runaway it could shut the valve. Or it could just cut the fuel :dunno:





d geek said:


> I'm not clear on how it could be set up to accomplish this without human intervention. On VW, the ASV (anti-shudder valve) is normally open. and uses residual vacuum to temporarily close the valve when the engine is shut down. After the vacuum is dissipated, then the valve opens back up for the next start up.
> 
> It is true that you can use the ASV to kill the engine in a runaway condition, but you'd need to pop open the hood, and reach in there while the engine is running close to redline to manually close the valve. It would definitely be effective, but you need to be confident in what you're doing and have nerves of steel.


Wow, this is pretty heavy stuff for a Friday afternoon. You guys must really dig this stuff.


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## d geek (Nov 26, 2008)

Hoooper said:


> does runaway (not in the Toyota sense, but the typical diesel sense) even apply to computer controlled diesels anyway? Seems to me it wouldnt be possible to get runaway if the computer is controlling fuel pressure and injectors. If the ECU says no fuel, then no fuel is what the engine gets. On the other hand, it wouldnt need to be human intervention. That throttle is electronically controlled so if the computer senses a runaway it could shut the valve. Or it could just cut the fuel :dunno:


Oil from the engine can feed a runaway situation. Since the ECU cannot control an oil leak from happening, it cannot remove that source of fueling. The only way to shut it down is to stall it out or cut off the air supply.

As I posted earlier, I'm familiar with the VW set up for the ASV, and it cannot shut down the engine from just switching off the key. If the ASV were electronically controlled then it could be set up to shut down when the key was switched off. But remember that it needs to be open the next time the engine is started.


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## Hoooper (Jun 17, 2013)

I see. Ours look very, very similar to other drive by wire throttle bodies I have worked with which the ECU has full control over the range, though ours look like they are powered closed instead of open. In short though if its like the others the ECU could use it to shut off air to the engine


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## BB_cuda (Nov 8, 2011)

Back to regularly scheduled programming: OP, did you find you leak at the turbos or is it the sooty place from the photo?

As an aside, European 320D *EGR* is vacuum controlled but the US M57 is electronically controlled. Europeans can put a dummy EGR that looks like the real deal and is really plugged up and don't even have to recode. I've seen them on ebay. We have a large electrical connector so we couldn't use that part. I'm not touching the throttle discussion between hoooper and D_geek.


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## d geek (Nov 26, 2008)

*eating crow*



floydarogers said:


> Also seems to be related to apportioning air mixture EGR versus "clean" air.





d geek said:


> I was wondering about that, but the EGR inlet appears to be downstream of the valve- so I don't think that's the case.





Hoooper said:


> if that throttle valve closes, the engine should pull more recirculated air when the EGR is opened, so it could possibly be used for that effect. Anyone with a Bavtech tool should be able to check into that. Mine wont be up and running until tomorrow.





d geek said:


> realoem.com shows the egr valve being the part that the egr plumbing goes to. A vacuum actuator is attached to the other side away from the inlet. This controls exhaust gas into the intake:
> http://www.realoem.com/bmw/showparts.do?model=VC31&mospid=48480&btnr=11_3717&hg=11&fg=40
> 
> The device with the oil is shown as a "throttle". As we all know, diesels run on max air all the time and adjusts fueling- there is no throttle to control air in normal operation. I'm pretty sure this is just to stop the engine smoothly.





Hoooper said:


> point was that the throttle could also be used to force the engine to pull more through the EGR than it would with that throttle being fully open. If the engine is not in boost then closing down that throttle a bit would force the engine to pull from the EGR more. Not sure if/how that would work under boost though





d geek said:


> You always want max air available for a diesel, so you'd never put a restriction in there. The EGR rate can be tighly controlledl with the vacuum actuated valve.





Hoooper said:


> I think youre missing the point. If the EGR is fully open and you still arent getting enough recirc, the only solution would be to draw more vacuum which would cause it to pull through the EGR more, and the only way to do that would be to shut the valve down some. Not saying this IS a use for that valve, but only a possibility. If someone has actual information on the ECU coding for the throttle control that would answer the question.


Guys- I think you are right about the EGR valve control being enhanced by the butterfly valve. Thanks for the pushback on this:
http://www.bimmerfest.com/forums/showpost.php?p=7733749&postcount=5


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