Diesel runaway HELP needed 🤯

[Alun1976]

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

 

[DivineChaos]

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

It's possible the timing belt jumped a tooth. You need the tools check that properly. There is a way to check cam and crank coralation in vcds. 12L overfull? How often do you check your oil? With that I'd assume you have a leaky injector or something. Let's hope you didn't hurt the bearings with that diluted oil.

 

[Alun1976]

Many thanks for your reply. I'll try and get hold of the tools to check timing and a copy of vcds .. I checked my oil approx a month after doing an oil change and noticed that it had risen a couple of mm of the dipstick. I didn't think much of it to be honest as it was minimal.. Id also never heard of leaking injectors or oil level increasing before. ..

The car has been used for lots of short journeys and the cooling fan was always running when I got out which I couldn't understand. My mechanic friend told me that its common on these for the cooling fan to always overrun but I feel its because its failed regen.. When I did oil change I put approx 4.8L in ... Therefore the remaining 7.2L was diesel.. I really hope bearings are OK ...

The dpf fault light would come on during the winter months every week and I'd take it for a motorway run and it would go off. Again my mechanic friend told me that dpf light comes on early on Audi which is a good thing. The summer months the dpf light was less frequent , say every fortnight , but cooling fan was always on after stopping engine.

So other than the possibility of blocked DPF and timing out what else could it be? Are your thoughts the same as mine? Thanks again.

 

[DivineChaos]

Many thanks for your reply. I'll try and get hold of the tools to check timing and a copy of vcds .. I checked my oil approx a month after doing an oil change and noticed that it had risen a couple of mm of the dipstick. I didn't think much of it to be honest as it was minimal.. Id also never heard of leaking injectors or oil level increasing before. ..

The car has been used for lots of short journeys and the cooling fan was always running when I got out which I couldn't understand. My mechanic friend told me that its common on these for the cooling fan to always overrun but I feel its because its failed regen.. When I did oil change I put approx 4.8L in ... Therefore the remaining 7.2L was diesel.. I really hope bearings are OK ...

The dpf fault light would come on during the winter months every week and I'd take it for a motorway run and it would go off. Again my mechanic friend told me that dpf light comes on early on Audi which is a good thing. The summer months the dpf light was less frequent , say every fortnight , but cooling fan was always on after stopping engine.

So other than the possibility of blocked DPF and timing out what else could it be? Are your thoughts the same as mine? Thanks again.

Short trips are not good for these tdis. And is your car under warranty?

 

[DivineChaos]

Doiles your Audi have a tandem pump? It's a vacume/ fuel pump. When these go bad it'll pump fuel into the engine.

 

[Alun1976]

Short trips are not good for these tdis. And is your car under warranty?

I think it's CFH.. How do I find out? There is a sticker on the timing cover with CFH on it.

 

[Alun1976]

Doiles your Audi have a tandem pump? It's a vacume/ fuel pump. When these go bad it'll pump fuel into the engine.

I think it might have. Does it run off the cambelt by any chance?

Edit ..... ive just checked and yes it does have a tandem fuel pump that is run off the cambelt. So that could have been the cause of the diesel contamination , or possibly 12 months of failed regens ... Is there any way of testing if the tandem pump is properly functioning? I suppose if the high pressure pump fails to it would cause poor idling and very slow to rev up?

 

[DivineChaos]

I think it's CFH.. How do I find out? There is a sticker on the timing cover with CFH on it.

Call the dealer, give vin and ask. You have the diesel gate warrenty there?

 

[DivineChaos]

I think it might have. Does it run off the cambelt by any chance?

Not sure. On the older tdis here it ran off the trans side of the head. The front of the motor would be a high pressure fuel pump. Front being where the serp belts are

 

[Alun1976]

Short trips are not good for these tdis. And is your car under warranty?

I've learnt this the hard way... In my opinion a car that you can't do regular short trips in, or else engine damage may occur, is not fit for purpose .. My first ever diesel and this is enough to put me off buying another for life. ...

I don't think it's still under warranty... It had full Audi service history until 48000 miles and I've owned the car about 18 months. It now has 60k on the clock..

 

[DivineChaos]

I've learnt this the hard way... In my opinion a car that you can't do regular short trips in, or else engine damage may occur, is not fit for purpose .. My first ever diesel and this is enough to put me off buying another for life. ...

I don't think it's still under warranty... It had full Audi service history until 48000 miles and I've owned the car about 18 months. It now has 60k on the clock..

Here in the states they have 40k dieselgate warrenty. From time of fix. It's a newer emissions diesel. Ask anyone that knows. They'll say to not short trip them.

 

[Randomhomelesstdibeetlegu]

That's not normal at all. I never had diesel dilute oil with failed Regen in the MK6.

 

[Alun1976]

OK I'm going to try and get hold of a copy of full version VCDS and check ignition timing . If I can't get a copy I'm going to use the timing alignment tools and check it that way.. Before I do that I'm going to disconnect DPF and see if it runs any better. If timing is good and DPF not blocked what else could it be? Could there be any way the intake could be blocked ?

 

[Randomhomelesstdibeetlegu]

Check fuel injector trim values. See what they are.

 

[Alun1976]

So my obd cable / interface isn't connecting to VCDS. I've seen the price of genuine ones and I'd like to try and avoid that if I can.. I was wondering do the cheaper non genuine ones work for checking timing and fuel trims? Or could you point me in the right direction to get a cheaper alternative than the genuine one..

 

[ccaissie]

I bought an off-market Vag Com system for cheap and it worked great for a while, but then quit. Ross-Tech won't help me because it's a fake system. The Ross-Tech software worked correctly but the interface failed....or something...

 

[Alun1976]

Just a quick update to this thread. I bought a second hand engine with turbo, all sensors and injectors on it. I swapped the injectors out my car for the ones in the second hand engine and it fired up straight away. This was after I'd checked the timing belt hadnt slipped , dpf not clogged and turbo spinning freely. The faulty injectors looked entirely normal when removed i.e. the tips hadnt blown off them as I had heard from a diesel mechanic. So the overrun condiiton must have damaged the injectors somehow or maybe the over rev into red line damaged them.

Now despite me having a few months trouble free motoring with a nice smooth engine, the horror story gets much worse..... WAIT FOR IT..... Three months later and I end up with a piston / conrod failure that came straight through the side of the block. The overrev had obviously stressed the internal components and it was only a matter of time before it went bang.

Anyway I could do with some help again please folks. Ive just fitted the second hand engine into the car which was running when removed from the donor car and it wont start sadly. I have a flashing glow plug light and two fault codes showing... P0113 and P0238 which relate to air intake sensor and and boost pressure sensor. I lost the will to live yesterday after I swapped the boost pressure sensor (with great difficulty) and the P0238 code didnt disappear.

Do any of you knowledgable people kindly have any suggestions? Im turning grey faster than you can say Husein Bolt!!

When swapping an engine does the ECU need to be programmed for new sensors or should it run fine?

Thanks peeps