Audi BRD engine suspect injector fault

   #41  

Pinpointdiag

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Has this car got a Dpf?
So the car can run fine hot and cold with no smoke and then intermittently there is a sudden and large release of thick white smoke is that what you are saying?

It's not hard to tell if the smoke your getting is coolant or vaporised fuel. And that's the first thing to prove. Some vaporised
Fuel in your workshop will make your eyes nip. Obviously you won't be working in an unventilated area without an extractor.
But if you do for a few minutes the smell and the nippie eyes prove it's fuel. It is also more slightly blue white than if coolant
Or you could drop the coolant but if the fault is intermittent you can't run long with no water and how will you know if there is no smoke due to there being no water or the fault has just not happened yet.

Any way there is no point chasing a coolant fault if it's fuel and visa versa. And you don't appear to be sure.
You say it's not coolant but Jack asked if there is raw fuel with the smoke and you say no. Did you think he meant
Liquid diesel dripping from the exhaust as that would be rare and I see plenty diesels with white smoke.
Most turn out to be compression issues. Cam timing, bent con rods after a water splash, that kind of thing.
Some injector faults. But if you have injectors that have done a bit of running to a specialist diesel shop to test, be carefull as
They can quite reasonably condem most old injectors and then you pay to get them all serviced and put them back in only to find
Your fault is still there. As all all injectors go out of spec as they age. With out any noticeable running issues.

Coolant leaks from EGR heat exchangers are becoming more common on all makes also though. If possible clamp off hoses to prove.

As for scope testing have a look at what can be done to test injector fuel delivery and scope injection correction factors between cylinder which can be checked in MVB with VCDS but not so easy on other makes
Also in cylinder pressure testing with a pressure transducer attached to a scope is a very powerful tool for proving compression and timing issues simply by removing the glow plugs or injectors which ever is easiest. Plus many other things that can't easily be tested any other way.
Check out some of this on YouTube if you like.
Just my opinions, hope it's some help.
 
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   #42  

Pinpointdiag

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For example by scoping the rail pressure sensor and an injector on the car you could see this kind of thing, pressure drop on pressure sensor when injector opens with out removing injector and having the test rig this guy has. https://youtu.be/AYCp4nQ0Xmg
 
   #43  

vagtuning

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Nice Video, but the BRD is no Common Rail, its a PD-Engine.
And therefor does not have a Railpressuresensor.
 
   #44  

Jack@European_Parts

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Easiest test rig to test PD spray patterns cheap: For diesel dykes and shops that do a lot of PD work.

Take a smoked PD head........ with bad cam available, and use the HPP pump fed with a reservoir into an old fish tank. Than pulse fire the injector or use a G28 and old ecu to trigger.

Then turn the cam with impact or belt motor.

Observe the show.........
 
   #45  

MartinsX

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Perfect DIY test stand for PD :thumbs:
 
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