Soot in engine bay and glow plug light

[SirTT]

Going to work on Thursday last week the car started driving "oddly", changing gears really eagerly, the throttle pedal went "soft" and the glow plug light started flashing. No other warnings. I pulled over, restarted and all was fine. During the day it did it 3 other times.
I took it to a mate who ran a diagnostic on the car and there were 3 underboost faults. I noticed that the "lid" for the airbox was off. Fixed that.
As the car has 58k (FSH, oil change very 9k) I thought it may benefit from a Terraclean so took it to a friends garage. The car behaved on the way down.
Whilst under the bonnet he noticed a load of soot next to the turbo on the suspension mount and the turbo casing itself.
There was 1% soot loading. It's going back in on Thursday to investigate the soot but as yet has not thrown a light.
Could the airbox lid have caused it to throw a light?
I read the thread with the other FL 2.0Tdi that had the soot in the engine bay but he rejected the car so there was no further work carried out.
Anyone else had this?
Thanks

[Envy]

If the air-box lid was passing air either way this will have confused the ECU. With airflow monitoring pre and post air filter it is possible that this would have caused excessive soot but it should not have been in the engine bay. Soot in the engine bay would suggest a blowing exhaust / turbo manifold or around the EGR Valve. 

[Stevey Y]

3 hours ago, Envy said:

If the air-box lid was passing air either way this will have confused the ECU. With airflow monitoring pre and post air filter it is possible that this would have caused excessive soot but it should not have been in the engine bay. Soot in the engine bay would suggest a blowing exhaust / turbo manifold or around the EGR Valve. 

Hi, totally correct, if the car is getting extra air from a source other than the air box the engine management system will demand more fuel to stop the engine from running lean, most default strategies that the ECU has at its disposal will do this as lean burns valves and pistons, until it reaches the point where it can't call up enough fuel to deal with the air , then the lights come on.

I can agree with Envy that the soot is most probably a separate problem.

[Keal30]

On 7/30/2020 at 2:09 PM, SirTT said:

Going to work on Thursday last week the car started driving "oddly", changing gears really eagerly, the throttle pedal went "soft" and the glow plug light started flashing. No other warnings. I pulled over, restarted and all was fine. During the day it did it 3 other times.
I took it to a mate who ran a diagnostic on the car and there were 3 underboost faults. I noticed that the "lid" for the airbox was off. Fixed that.
As the car has 58k (FSH, oil change very 9k) I thought it may benefit from a Terraclean so took it to a friends garage. The car behaved on the way down.
Whilst under the bonnet he noticed a load of soot next to the turbo on the suspension mount and the turbo casing itself.
There was 1% soot loading. It's going back in on Thursday to investigate the soot but as yet has not thrown a light.
Could the airbox lid have caused it to throw a light?
I read the thread with the other FL 2.0Tdi that had the soot in the engine bay but he rejected the car so there was no further work carried out.
Anyone else had this?
Thanks

Did you find the cause of the soot, sounds like a similar problem I have at the minute 

[SirTT]

No I haven't. Ironically the car is now running just fine with no Glow Plug light after 4000 miles but the soot is still building up there. I cleaned it off a few weeks ago but it's as bad as ever.

[shiraz121]

Can someone help me. My car goes in limp mode with the spring coning on dashboard when I put my foot down when rev goes over 3000 also car has stopped regerning now. Tried regern but doesn't allow it. Audi 2014 2.0 tdi 190hp 

[Steve Q]

On 9/3/2020 at 1:41 AM, shiraz121 said:

Can someone help me. My car goes in limp mode with the spring coning on dashboard when I put my foot down when rev goes over 3000 also car has stopped regerning now. Tried regern but doesn't allow it. Audi 2014 2.0 tdi 190hp 

Dog could be blocked. Best to get a diagnostic check carried out to see what fault codes flag up