Alun1976
Member
OK so here's the story... Audi A1 2.0 TDI 2012 ... 60k on the clock ... CFH engine.
So I was driving down motorway when suddenly the car started to accelerate on its own so I switched ignition off and stupidly pressed the clutch .. The car over revved for approved 2 seconds and massive plumes of blue smoke came out the exhaust. The whole episode lasted approx 8 seconds . The car cut out as I'd turned the ignition off and I pulled over at side of road.. I managed to crawl the car home with very light revs ( No more than 2k) in first and second gear with no smoke . There was an awful smell of like a really hot engine entering the cabin but temp was normal. It seemed like incomplete combustion of diesel but not sure.
The engine oil was drained and had way too much in there.. Approx 12 litres.. I can only assume after finding out about this terrible diesel design flaw that repeated failed DPF regens has seriously diluted the oil with diesel. I assume that the oil/diesel mix was somehow sucked into combustion Chambers and caused the runaway phenomenon.
So the car will start but its extremely rough. There are no fault codes. The engine rocks so badly on the engine mounts. The smell from the exhaust is not the same as it used to be (not like I go sniffing exhaust pipes for fun like ) but rather a hot engine smell. The engine is knocking and sounds rough. I've done a compression test and all cylinders have more than the minimum of 19 bar and max difference between cylinders is less than 5 bar. I thought I'd bent a valve with the over rev but obviously not. When I remove the injector connectors from each injector individually the engine either cuts out or there is a clear dip in revs and engine note. I assume this indicates that all 4 cylinder injectors are therfore working correctly?
The car revs up very slowly.. There is no throttle response like there used to be. Ive never owned a diesel before and if I'd have known more about DPF , regens, and diesel runaway , I'd have probably stuck with petrol. Anyhow I need to get it fixed and I'm looking for some advice please on what could be causing the above symptoms.. I have a couple of theories myself. Firstly could it be a completely blocked DPF? The exhaust gas flow seems decent thought coming out the exhaust. Secondly could the over rev have knocked the timing out? Maybe cambelt jumped one tooth ... If so , would this cause all the above symptoms.
I'd appreciate any help please folks .. any other ideas.. I have a friend who works as a mechanic and he said the knocking sounds like the bottom end has gone which I agree to some extent, but fail to understand why the engine runs so rough and only revs up very slowly.. If the bottom end had gone then surely I'd still have some throttle response.. Thanks
So I was driving down motorway when suddenly the car started to accelerate on its own so I switched ignition off and stupidly pressed the clutch .. The car over revved for approved 2 seconds and massive plumes of blue smoke came out the exhaust. The whole episode lasted approx 8 seconds . The car cut out as I'd turned the ignition off and I pulled over at side of road.. I managed to crawl the car home with very light revs ( No more than 2k) in first and second gear with no smoke . There was an awful smell of like a really hot engine entering the cabin but temp was normal. It seemed like incomplete combustion of diesel but not sure.
The engine oil was drained and had way too much in there.. Approx 12 litres.. I can only assume after finding out about this terrible diesel design flaw that repeated failed DPF regens has seriously diluted the oil with diesel. I assume that the oil/diesel mix was somehow sucked into combustion Chambers and caused the runaway phenomenon.
So the car will start but its extremely rough. There are no fault codes. The engine rocks so badly on the engine mounts. The smell from the exhaust is not the same as it used to be (not like I go sniffing exhaust pipes for fun like ) but rather a hot engine smell. The engine is knocking and sounds rough. I've done a compression test and all cylinders have more than the minimum of 19 bar and max difference between cylinders is less than 5 bar. I thought I'd bent a valve with the over rev but obviously not. When I remove the injector connectors from each injector individually the engine either cuts out or there is a clear dip in revs and engine note. I assume this indicates that all 4 cylinder injectors are therfore working correctly?
The car revs up very slowly.. There is no throttle response like there used to be. Ive never owned a diesel before and if I'd have known more about DPF , regens, and diesel runaway , I'd have probably stuck with petrol. Anyhow I need to get it fixed and I'm looking for some advice please on what could be causing the above symptoms.. I have a couple of theories myself. Firstly could it be a completely blocked DPF? The exhaust gas flow seems decent thought coming out the exhaust. Secondly could the over rev have knocked the timing out? Maybe cambelt jumped one tooth ... If so , would this cause all the above symptoms.
I'd appreciate any help please folks .. any other ideas.. I have a friend who works as a mechanic and he said the knocking sounds like the bottom end has gone which I agree to some extent, but fail to understand why the engine runs so rough and only revs up very slowly.. If the bottom end had gone then surely I'd still have some throttle response.. Thanks