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Audi A6 C7 No Power & Wont Drive


BigTownz
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Hi Ryan, will deffo have a look at the video as when I watched my belt being changed it was from at least five feet away so I could not observe any fine detail and had to get a bit further back when the swearing started when a ratchet broke.

Now have THE RIGHT and only part numbers for both sensors should you or I need them, believe me when I tell you one of the cars he showed me which they had just started on the belt even though still tensioned you could move it about 10mm up and down, I rang him today and he is of the same opinion as I am that there will be no detrimental effect on the engine😁.

Steve.

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That's great news, thank you...

So, the garage have sent me a couple videos now and my belt had failed due to the crank seal failing and the belt being covered in oil. 
 

I have uploaded two videos to my google drive for you or anyone else to view. Please note these might not play immediately due to still processing. I have also had to cut the videos down to hide my registration and to localise to the immediate issue (as they done a full car inspection via video)

Video 1 is when it first arrived at the garage

https://drive.google.com/file/d/1uX70gIGqmE8P1npxSmqayAnmLh9zAup8/view?usp=sharing

 

Video 2 is after stripping the required area down

https://drive.google.com/file/d/1uYw1irhYg2WdgOrm2SH8DHOdvejRDZqV/view?usp=sharing

 

The quoted cost of repair is:

Cam belt £625 VAT Inc. - With this they also change the water pump, the coolant fluids & give a lifetime warranty on the cam belt. When it needs changing again its free.

Crank seal £95 Vat Inc.

So far that's £864 😞. But if it gets my baby better then so be it lol.

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Hi Ryan, thanks for letting us know the final outcome and posting the videos, good skills, at least anyone like myself can whip the cam cover off just to get a quick visual, to be fair I think I would end up giving it to a garage as removing the timing belt pullys is no simple task and you need an upgraded pin kit to lock the cams and crank back into position, the lifetime warranty is a real deal as you won't have to worry about it ever again, price wise take some consolation from thinking about what Audi would have charged to do the job at least you escaped that, take care and good luck.

Steve.

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Just to give an update, cam belt and water pump changed, car started up, was running for 5 minutes, sounded perfect with no knocking noises from the engine which is a positive..... But then it cut out 😭. They are in the process of stripping it back down to ensure they have done everything correct. I have told them to check the DPF as when I was running the test before it stopped running it was stating there was 30.9g of soot measured.

Is 30.9g of soot high? And can this cause the vehicle to stop running?

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Ive just spoken to a dpf specialist and they have said 26g is the equivalent to 80% blocked. 32.5% is 100% blocked so looks like the bill just got higher as it can't be regenerated at that level. 🙈🙈🙈🙈

 

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in my 3.0 tdi from 2007 the regeneration starts when it is 36 grams, if your car has passed update from dieselgeit it should be bigger than 36 g, acquaintances say that the regeneration is done at longer intervals. look at the differential pressure sensor, it is a consumable and although it does not measure exactly the car does not show an error

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8 hours ago, BigTownz said:

Ive just spoken to a dpf specialist and they have said 26g is the equivalent to 80% blocked. 32.5% is 100% blocked so looks like the bill just got higher as it can't be regenerated at that level. 🙈🙈🙈🙈

 

Hi Ryan, I don't think the Dpf ash level is your problem, as why would the car have run at all if the DPF is totally blocked, think about it Ross Tech reckon the max loading is around 45% when it should kick off its own regeneration, as I said the workings of the Audi are fairly new to me but I have in the past had plenty of problems with the last Ford I owned not regenerating because the vaporiser unit had failed and     due to readings on Forscan I once had a loading of 220% which I got round by doing a twenty five minute forced regen whilst driving up the A12, if the car is static Wurth do a wonderful cleaning kit you can squirt through temp sensor hole, leave it overnight and then run the car to get rid of any residue, reset the DPF learned values and off you go. 

On cheaper cars the DPF core or cake is made of cordierite this is a very good filter but has a lower melting point when compared with the more expensive cars silicon carbide core, the advantage of this is that the manufacturers of these offer refurbished units at half the price of new and the only refurbishing they will have done is sonic cleaning.

Audi diesels have no vaporiser units as they are post injection regenerated engines, this  means that when the ECU receives readings from the DPF pressure sensor telling it that the soot levels are high it retards the timing slightly and over injects diesel into the bores this won't burn very efficiently but the heavily vaporised fuel is flung into the exhaust where it meets the primary chamber at the front of the DPF, this then combusts and burns the soot particles turning them to ash, during the regeneration cycle the the EGR valve is shut and I would guess Adblue injection is suspended as either of these elements would pollute the extra fuel which would in turn reduce the efficiency of the regeneration.

Steve.

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Sorry for the delay, just to give you an update, my car is still poorly and it is currently with a DPF specialist. They have checked the DPF and it was full of soot and ash. They have also checked the EGR valve which was also full of soot. After sorting these there is still the apparent issue that theres no power and it sounds rough when running. They have performed compression tests on both sides of the manifold, one side seems clear and the other seems blocked. So they believe the manifold is blocked and needs clearing.

Now im no expert on this sort of thing, is this actually an issue that can cause my symptoms? 

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6 hours ago, BigTownz said:

Sorry for the delay, just to give you an update, my car is still poorly and it is currently with a DPF specialist. They have checked the DPF and it was full of soot and ash. They have also checked the EGR valve which was also full of soot. After sorting these there is still the apparent issue that theres no power and it sounds rough when running. They have performed compression tests on both sides of the manifold, one side seems clear and the other seems blocked. So they believe the manifold is blocked and needs clearing.

Now im no expert on this sort of thing, is this actually an issue that can cause my symptoms? 

Hi Ryan,

I am guessing that they are talking about the inlet manifold and an educated guess would be that the swirl flap mechanism has failed, these monstrosities are a brilliant idea in principle, but being as on our engines they are cheaply made they tend to give problems as plastic limiters are fitted to stop the flaps from over running.

It could of course be just good old fashioned gummed up manifold as this item has to deal with EGR gas as well as oil vapour scavenged from the crankcase ventilation system, I had this with my last cab which did not have swirl flaps but at 270,000 I had the inlet manifold off to clean it out the inlet ports were actually only using about a third of the port to breath the rest was black tar , the tar is caused where the EGR gas meets the cooler crankcase gas which has a lot of engine oil vapour in it which is hard to burn so it contents itself by forming tar.

Ask them if they can run a scan on the car and see if it throws up any codes relating to the swirl flap mechanism, keep on with the updates as its all good info.

Regards Steve.

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Hi Steve, I went to the garage today and had diagnostic tests ran on the car, but it doesn't bring up a single error???? The car ran fine but sounds deep when you try to rev it. The only way I can explain the sound it when you get a boy racer that drills holes in his airbox or puts a K&N on to make it sound beefy. Any further thoughts?

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6 hours ago, BigTownz said:

Hi Steve, I went to the garage today and had diagnostic tests ran on the car, but it doesn't bring up a single error???? The car ran fine but sounds deep when you try to rev it. The only way I can explain the sound it when you get a boy racer that drills holes in his airbox or puts a K&N on to make it sound beefy. Any further thoughts?

Hi Ryan, bored again today so I spent a bit of time looking around the engine on my car, the inlet manifold is unlike anything I have ever seen its an all aluminium work of art with the Throttle valve at the bulkhead end and behind the throttle is the EGR valve this seems to enter the manifold further down from the throttle so it doesn't seem to go in on the fresh air side of the turbo pipe.

I did a bit of research on the inlet manifold it would appear there are no swirl flaps in the manifold just a rather complex little intercooler system for the EGR every thing on the manifold is water cooled and looks like hours of FUN to strip out.

With regard to the throaty induction roar it sounds like the induction pipe that runs from the other side of the MAF sensor is getting extra air from somewhere have a look at the polythene pipe where it attaches to the MAF sensor then inspect the pipe as far down towards the rear of the engine as you can, I have had this before where there is a rubber joint between the turbo intake and the polythene pipe, the rubber union had split and the car sounded deeper as you say when revved, but the easiest place to start is where the polythene pipe joins the air box as I have had problems when I disconnect the pipe to get the air filter out, the problem is that the pipe is so flimsy  when you push it back on that the lower edge folds under and leaves a gap one side.

The problem is the MAF won't spot the extra air coming in as it won't register a fault because it considers it doesn't exist, the only thing that bought the problem to light was the induction roar and the fact that the car was regenerating the DPF about five times in every hundred miles as the ECU picks up the extra air via the MAP sensor readings and adjusts the fueling to compensate so the thing over fuels and blocks the DPF quicker.

Regards Steve.

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  • 2 weeks later...

Evening fellow members. The reason I havent posted any updated is due to not actually having any until today. So they have started stripping parts from the engine and have come across a totally blocked egr cooler. As advised by the garage I will be replacing this, but the garage have also advised I change the turbo as the blocked egr cooler could of damaged the turbo and before stripping down they claim it thrown up a "turbo boost pressure error twice" (funny thing is my VCDS didnt pick this up?). Also they say the turbo shaft has some horrizontal movement which I thought was normal. Now my questions are:

1. Can the blocked egr cooler be the reason for no power and failing to drive faster than 10mph?

2. Do you think the turbo will need replacing too?

Remember my dpf was 100 blocked and now it appears the egr cooler is affectively the same amount blocked.

After passing light through the main opening, light was only visible through three of the tiny holes.

 

 

20210309_164925.jpg

20210309_164906.jpg

20210309_165000.jpg

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Hi Ryan, good pictures although they look pretty horrific they will definitely give anyone viewing them a real good idea of how the exhaust gas treatment system works and what can stop it doing its job, I might assume your car does not run on adblue as there seems to be a distinct absence of crystallisation on the EGR cooler which I am reliably informed normally causes the blockages in the cooler.

The blockages shown are pretty standard for a high milage Diesel engine the oily crud is caused by the the crankcase gas being sucked into the intake system via the PCV unit this is basically engine oil vapour and moisture based contaminants from the combustion process, this is not easily burnt and forms the oily tar in the bottom vents of the cooler especially with the latest fad for cooler running engines to combat the Nox situation, not ideal really, which is why I am researching the possibilities of a catch tank system, ok it will be a pain emptying the tank every week but at least it stops 80% of the solid and water getting into the induction system and causing the the problems you have now.

Unfortunately from what I can remember the increased back pressure caused by the DPF blockage will actually kill the turbo due to the decreased flow in the exhaust, the only saving grace with the rocker situation is that the rockers are designed to break rather than hold the valve down until it gets close and personal with the top of the piston and mullers the piston crown whilst turning the valve into a piece of modern art, I always thought that was a bright idea of PSA to make the rockers so they deform a bit and then pop off of the mounting and fall into the deep oil channel under the camshaft I have even seen realtime where the rocker has failed on one of the exhaust valves but the engine still runs even though not very well because it still has one of the two valves working, in the final analysis its a lot cheaper than new valves and pistons.

I really admire your resolution in pursuing this as I know from experience its not a nice place to be, so far into this now that giving up would be a costly experience and will rob you of what will be a usable vehicle in the end, the only other thing that I might suggest is ask them as nicely as possible to put some clingfilm or plastic caps over the fuel rail outlets as any debris that get in there will definitely cause injector problems in the future.

 

Regards Steve. 

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Thanks for your input Steve, it really does help paint a better picture.

My car does take adblue and tbh it seems to drink it so fast and I'm having to fill it up every couple of months. I know you and other will advise against it but I have opted to have the dpf replaced with a hollow one (obviously for track racing purposes 😉) and have bought a replacement turbo and egr cooler. With the dpf amendment it will require a remap which I have also been asked if I want the egr blanking/disabling and the adblu disabling. Now I have told them no to the egr being blanked/disabled, but would having the adblu diasbled affect the egr cooler? As after your comment about the crystallisation I dont want the replacement part to be affected.

Also, noted about the injectors I will get on to them

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51 minutes ago, BigTownz said:

Thanks for your input Steve, it really does help paint a better picture.

My car does take adblue and tbh it seems to drink it so fast and I'm having to fill it up every couple of months. I know you and other will advise against it but I have opted to have the dpf replaced with a hollow one (obviously for track racing purposes 😉) and have bought a replacement turbo and egr cooler. With the dpf amendment it will require a remap which I have also been asked if I want the egr blanking/disabling and the adblu disabling. Now I have told them no to the egr being blanked/disabled, but would having the adblu diasbled affect the egr cooler? As after your comment about the crystallisation I dont want the replacement part to be affected.

Also, noted about the injectors I will get on to them

Hi Ryan, logically I can see no reason why the Adblue delete would cause you any problems as is all it does is convert Nox particles to Nox2 which is an inert particle, same particle without the potential to convert into nitric acid if ingested, the EGR refusal seems good as it will cut down on the Hydrocarbons which will register an increase at the MOT test, just a word to the wise make sure the guy doing the remap is famous for his success in that field, correct software etc and get them to check the emissions when he has done the job.

I used two tanks of supermarket fuel [against my better judgement] during the first lockdown as it was the only chance I had to get diesel when we went out to get food, the noticeable side effect was that I went through ten litres of Adblue in record time despite the all time low milage I was doing, conclusion was that the inferior fuel created more soot and therefore used far more Adblue to counteract this anomaly, since going back to work and using the Shell fuel I normally use the Adblue consumption has dropped by about eighty percent.

The Adblue delete has been quite a popular pastime for the Transit minibuses in the cab trade as their love of supermarket fuel was costing a fortune in Adblue, you are quite safe with that one for a while as Boris will be to busy trying to screw more money out of Joe public to pay for Covid, the fun begins when he gets bored and starts on the motorist again and gives VOSA the funds to buy the equipment to test Nox particles, but I cant see that happening as he reckons we will all be driving Milk Floats in another ten years.

 

 

Steve.

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Morning all.... so, to update all to my recent issues, I am now happy to say I have my car back and shes running perfectly 🥰

All in all its cost me approx £2250 which im not happy about but "aye ho" it had to be done. The bitter pill to swallow was it went to three garages and the £700 bill from the first garage could of been avoided so please make sure you do youre research on garages before hand...

Changes to car:

1st garage - timing belt, waterpump camshaft pully seal -  £720

2nd garage - dpf removal, economy remap with dpf delete, ad blue delete - £350

3rd garage - Turbo replacement (I sourced for £200), egr cooler replacement (I sourced for £40), egr clean, 16 crank arms, new oil filter, new air filter, new oil, new breather pipe - £900 (price is high, but this version of audi has the most awkward engine, making it hard to work on)

£40 - tow recovery charge

 

Before I conclude this thread, I have a few more questions.

1. Should I have the swirl flaps deleted (programmed to stay open all the time)? And what are the benefits of this? (Dpf specialist recommended this)

2. Should I get the power remap which would take it from 190bhp to 240bhp

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Hi Ryan, good news, but expensive news, I really would not be bothering with the swirl flap delete as I have looked at the inlet manifold in depth and I am almost convinced that CNHA engine has not got them I will dig in further but in view of the engineering of the manifold [All Alloy] I cant see why they would spend fortunes on putting in swirl flaps into what is already a highly engineered part, the swirl flaps are used normally to create a vortex effect with the fuel/air mixture , this means that the mixture is already turbulent when on induction it hits the swirl bowl on the piston crown it creates a far more efficient mixing of  fuel/air thus a better level of combustion, less emissions.

As for the power remap I would say that is a matter for personal preference, myself I cant rationale putting an engine with that sort of milage under that much extra strain, if you look at the ways engines are developed they keep upping the BHP/Torque until they break, then having reached a maximum state of tune they reverse the process 40% which is the reliability factor and ensures a good level of longevity for consumables such as gearboxes clutches drive shafts, raising the BHP will only eat into the reliability factor of your vehicle.

With the DPF delete you will without doubt gained somewhere near another 30 BHP from that alone, example being a guy on our cab fleet who had the DPF delete done on his 115 BHP Mondeo after this was done the car would give my 200 BHP Mondeo a hard time up to 70MPH, you don't realise how much power is robbed from diesel engines just by the DPF.

Steve.

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Thank you for all your input Steve, it really has made a difference. As for the current gain in bhp, youre right, my car feels alot quicker than it did previously 🤓.  

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2 hours ago, BigTownz said:

Thank you for all your input Steve, it really has made a difference. As for the current gain in bhp, youre right, my car feels alot quicker than it did previously 🤓.  

Hi Ryan, my pleasure, I don't consider myself an expert but during the 870,000 miles living with diesel engined cars I have learned a great deal, but one factor remains constant they all work on the same principles, as I said Audis are new to me but to say the least the thinking behind the engineering is superb, yes I agree with the mechanic that any DPF/Cat problems are a pain as you have to remove most of the front of the car to get at them but the trade off is that should you wish to change any sensors they are mostly at the top of the engine bay, MAP MAF Oxygen sensors, even the EGR is accessible from the top of the engine, the north south engine layout definitely works, I think they have had a real go at making maintenance as simple as possible for the Audi techs at the franchised dealers whilst making sure[ the how to] information is as difficult as possible to get to, thank god for youtube/VCDS it must drive the motor manufacturers mad the amount of free useful information out there, all supplied by people who get a kick out of helping their fellow man avoid the main dealers.

Regards Steve.

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