A3 1.6 TDI 2013 Glow plug light lit, limp mode, won't rev above 2400rpm. EGR?

[Allegedly]

Hi all, Rob, newbie here. 

My wife's A3 began to show the glowplug heater light on a drive home from Oban, here in the Highlands. The car then appeared to go into 'limp mode'.

She stopped and restarted the car, as necessary, in order to make it home. 

Most of her journeys are short, work and/or about town so I guess it has never gone into a 'regeneration'...though to be fair, I/we didn't actually know to do that and unlike new models, the 2013 doesn't advise higher speed runs. 

After googling like mad, I suspected the DPF and so used a well know spray through the sensor inlet. Lots of smoke upon starting and hoped that would cure it. 

A run after wards as directed on spray and youtube instructions seemed to go okay until glow plug light began flashing again on way home.

I managed to get it onto a diagnostic machine in a friendly local garage and readings came up EGR related faults.  Much sucking of teeth from mechanice...."It's the 1.6 tdi, isn't it? Ohhh. Difficult".

Well, I've googled the hell out of it and yes, it's right at the back of the engine, under the turbo and I think removal is beyond my basic mechanical skill set and tools (I drive Land Rovers and so am used to fixing stuff). Also, we're pretty much in the middle of nowhere so can't just pop into the big name suppliers/stores.....online takes a wee bit longer.

I bought a Holts EGR aerosol cleaner, 500ml, and following instructions (again) sprayed it into intake hose, after the MAF. 

A question....doesn't this just blow it into the turbo, not the egr?      Bottom line...It didn't work. Thoughts?

I've seen a video of youtube of a mechanic spraying what appears to be a 5lt container of DPF flushing cleaner into the air intake hose of one of their company vans to clear EGR and DPF and apparently, it works, light/faults gone, albeit for a year at a time.  Thoughts?

I've also seen one guy spraying Mr Muscle oven cleaner into the air intake, supposedly cleaning the egr, turbo, dpf and all associated pipework. Thoughts...besides Oh Er.

I have read about this being used on the turbo vanes in A4's but again, how to get it into the EGR and not everywhere else?

All and any advice is very  welcome and please feel free to give opinions on the last couple of points.....if it was just a question of only doing possible harm to an all ready malfunctioning valve, I'd be trying it now but lack of knowledge of the potential for damaging other parts in the exhaust system is holding me back. 

As I'm hovering around retirement age and a low earner, the prospect of laying out between six and eight hundred pounds to get this fixed is stunning. Not even sure we can afford to get it fixed.

Any one near the Fort William area with a code reader and more knowledge than me (not hard) who'd be happy to swap tea and/or beer tokens for their help and input?

Hope everyone keeping safe in these uncertain times,

Cheers 

Rob

[Steve Q]

Definitely sounds like dpf and or egr. You can try and clean it by removing it. Alternatively you can get a garage to do a forced regeneration. But ultimately you might need a new dpf or egr or both. 

[cliffcoggin]

Rob. I agree with Steve that it is likely to be EGR and/or DPF. How to remove them I do not know as mine is a 2 litre. I believe Gareth has a 1.6 litre so let's hope he will chip in.

[Stevey Y]

19 hours ago, Allegedly said:

Hi all, Rob, newbie here. 

My wife's A3 began to show the glowplug heater light on a drive home from Oban, here in the Highlands. The car then appeared to go into 'limp mode'.

She stopped and restarted the car, as necessary, in order to make it home. 

Most of her journeys are short, work and/or about town so I guess it has never gone into a 'regeneration'...though to be fair, I/we didn't actually know to do that and unlike new models, the 2013 doesn't advise higher speed runs. 

After googling like mad, I suspected the DPF and so used a well know spray through the sensor inlet. Lots of smoke upon starting and hoped that would cure it. 

A run after wards as directed on spray and youtube instructions seemed to go okay until glow plug light began flashing again on way home.

I managed to get it onto a diagnostic machine in a friendly local garage and readings came up EGR related faults.  Much sucking of teeth from mechanice...."It's the 1.6 tdi, isn't it? Ohhh. Difficult".

Well, I've googled the hell out of it and yes, it's right at the back of the engine, under the turbo and I think removal is beyond my basic mechanical skill set and tools (I drive Land Rovers and so am used to fixing stuff). Also, we're pretty much in the middle of nowhere so can't just pop into the big name suppliers/stores.....online takes a wee bit longer.

I bought a Holts EGR aerosol cleaner, 500ml, and following instructions (again) sprayed it into intake hose, after the MAF. 

A question....doesn't this just blow it into the turbo, not the egr?      Bottom line...It didn't work. Thoughts?

I've seen a video of youtube of a mechanic spraying what appears to be a 5lt container of DPF flushing cleaner into the air intake hose of one of their company vans to clear EGR and DPF and apparently, it works, light/faults gone, albeit for a year at a time.  Thoughts?

I've also seen one guy spraying Mr Muscle oven cleaner into the air intake, supposedly cleaning the egr, turbo, dpf and all associated pipework. Thoughts...besides Oh Er.

I have read about this being used on the turbo vanes in A4's but again, how to get it into the EGR and not everywhere else?

All and any advice is very  welcome and please feel free to give opinions on the last couple of points.....if it was just a question of only doing possible harm to an all ready malfunctioning valve, I'd be trying it now but lack of knowledge of the potential for damaging other parts in the exhaust system is holding me back. 

As I'm hovering around retirement age and a low earner, the prospect of laying out between six and eight hundred pounds to get this fixed is stunning. Not even sure we can afford to get it fixed.

Any one near the Fort William area with a code reader and more knowledge than me (not hard) who'd be happy to swap tea and/or beer tokens for their help and input?

Hope everyone keeping safe in these uncertain times,

Cheers 

Rob

Hi you really need to post the codes for a near ball park diagnosis, what is the milage on the vehicle?, most of the spray down the inlet cleaners only work when the engine is nice and hot anything like very warm won't work as the EGR won't be open, steer well clear of Mr Muscle as this contains caustic and the sensors down the line will loose their coating and malfunction, sensible idea the potential for more damage, if in doubt leave it out, any chance of the garage giving you a print out of the codes they unearthed.

Steve.

[Allegedly]

Hi guys,

Thanks for the reply's, good input. Confirms what I thought. 

The garage did a quick diagnostic so I'd have to go back and 'beg' another reading.....they didn't do a forced re-gen but after what the mechanic said, " yes, high engine temp is necessary"...apparently the revs can go up to near redline levels during the re-gen for quite longish periods . I'd mentioned the dpf as being a likely culprit but after clearing it, he said the only indication was egr and air quality defect. 

Incidentally, when I sprayed the large bottle of dpf foamy cleaner (which seemed to last as long as a roll up in a gale), I had loads of grey smoke for about three to five minutes then it cleared. 

I found (after seeming hours of searching), two vids on the 1.6, both good and, tbh,  with better kit I'd go for it. as it's just spannerin'....but outside in the NW Highlands on a gravel track in early spring.....I've rebuilt the front of a Landy Discovery in the snow in March about six years ago after hitting a very large stag one night and I think twice'd kill me!

By the way, both vids give a clear methodology and detail. May put a link up on here as so many posts don't seem to even know where  the egr or dpf is, same as me until a few days ago!

One point that the 'serious' techs pushed was the fact that due to the distance between the egr and source of heavy particles resulting in mainly just 'soot' in the egr , was the real possibility of an electrical fault on the egr, necessitating a swap  out anyway. Apparenty, a regular problem,

I'm tempted to throw another twenty five quid at it and try the  five ltr flushing fluid (vetech professional dpf cleaning fluid) , sprayed in mist form into the intake to see if it clears before just parking up the car until I can afford getting a garage to do it. Lot of liquid, 5ltrs, surely got to have some sort of effect.....and yes, i know, effectively relieving me of twenty five quid.....

I'll post the results either way and put up those vids...

Thanks again,

Rob

Edited February 26, 2022 by Allegedly

[cliffcoggin]

As an ex-chemist I do not not believe that anything that survives passage through the engine without destroying it will any effect on carbon in the DPF. The internet is full of such snake oil treatments.

This site

https://garagewire.co.uk/news/game-changing-dpf-cleaner-is-a-profitable-solution/

indeed suggests that the DPF should be immersed overnight in the cleaner, not poured into the intake.

[Allegedly]

Hi Cliff,

Good point and yes, I'd read that post too, after seeing the container in the youtube vid and googling it.

I agree, that, ideally, removing either fitting, egr or dpf, and a carrying out a proper cleaning would be the logical answer and in a different engine layout I'd go down that route in a heartbeat but with the 1.6 tdi, the accessability means it's at the difficult end of the spectrum for DIYers and garage hourly labour charges for 4 - 5 hours result in a very large bill. With better facilities here, I'd have a go but as I mentioned in a previous comment, I just don't have the option. 

It's annoying but lack of knowledge in this case, until it's too late, is proving costly and yet it's so easily avoided. For some reason, (touch every bit of wood in sight), I've never suffered from these issues in my long string of diesel Landies....probably the only thing that hasn't gone wrong with 'em. But the little Audi has proved to be generally a very reliable little car, until this. 

I've contacted a few local self employed mechanics for a price of egr replacement as a heads up and found a guy relatively local who is experienced with using his 'reader' who may be able to help. 

This vid shows the work involved and one lads 'method'. It also shows the location of the various fittings in question for those, who, like me, didn't know. 

Think I'll also put a link up for the use of flushing fluid in a company van. I'm still a bit confused about that amount of fluid going into a turbo diesel not !Removed! with the engine (possible hydraulic lock?). 

Thanks for the input.

 

[Allegedly]

Video showing fluid input to clear engine fault light. 

https://www.youtube.com/watch?v=it_Grz7K1TQ

 

[cliffcoggin]

It looks to be swine of a job Rob, yet I see no alternative to somebody getting underneath to remove the EGR valve, and even then there is no guarantee of success.

A word of caution for when you visit the mechanic: don't take faults reported by a code reader as gospel. They need to be interpreted by a knowledgable and experienced human brain, else you could be throwing money into a bottomless pit trying to overcome them.

[Allegedly]

Hi Cliff,

Thanks for your points, agree completely. 

The mechanic was an experienced one....lad in a very well known national chain of garages...got a freebie as my daughter knows the manager!

He had actually worked on the 1.6 engine a few times before and knew straight away what it entailed, ( It was him who told me about the correct 'forced regen' procedure and required engine temps while we discussed what I suspected was the problem....dpf )  and was fairly sympathetic when it turned out to be the egr that was flagged up. He also knew they weren't going to get the job and recommended a few local independents that in his opinion were reliable. 

A friend of my sons' has owned a series of Audi's and has a reader. He does all his own maintenance and,  in fact, deliberately buys them with faults so as to get a much reduced purchase price, He is pretty knowledgeable so I'm going to see if he'll check the codes for me again....and give his opinion too.  I'll post those details as I get them. 

I appreciate this all looks like trying to do it 'on the cheap' but needs must. 

Thanks again, 

Rob

[Allegedly]

Hi All,

Just to recap.....

The symptoms my wifes A3 1.6 tdi 2013 has experienced are:

Engine Management Light on dash. Was lit for a while so don't do as I did and ignore it, try to do a regen at the very least.

Glow Plug Light on dash, flashing.  This is clearly a warning and about to go into 'Limp Mode'.

Car goes into Limp Mode.....very poor throttle response, slowing and poor acceleration. Unable to get rpm above 2400rpm and struggling like hell to get there. You can pull over somewhere, if possible, and stop/restart your car and it may not come back on immediately. Ours does with couple of minutes.

The spray 'remedies' I tried, relatively cheap-ish, didn't cure the problem (see above) but may help if your EML has only just come on, according to a number of posts I found. Clearly I left it too long. 

Not sure about the DPF...sprayed that too and it made smoke like a b****r for 5+ minutes and starting and revving a bit so may have helped there....not the cure to the main problem though.     Ignorance is not an excuse to a car, apparently.

 

As I said earlier, I visited the lad with the Ross Tech VCDS this afternoon and these are the codes that he found:

Fault 1.  7563 - EGR Sensor 1

P046C 00 (232) - Implausible Signal

Fault 2.  7336 - EGR System 

P0402 00 (096) - Excessive Flow.

 

 

I'm standing by on a price by local self employed mechanic for 'best price' for job.

Meantime, I did a bit of 'googling' for causes and options....quite a variety of symptoms and things to check. 

Possible faults linked to P0402 codes - excessive flow in EGR ...https://www.whitesautomotive.com/3-common-causes-of-excessive-egr-system-flow

What are the Possible Causes of the P0402 Code?

• Faulty differential pressure sensor.
• Blockage in the EGR passages (due to carbon build-up)
• Failing EGR valve.
• EGR valve not opening due to lack of vacuum.
• EGR control circuit issues, such as damaged wires and poor connections.

What repairs can fix the P0402 code?

1. Replacing the stuck open EGR valve.
2. Replacing a broken catalyst in the exhaust.
3. Replacing an EGR temperature sensor or cleaning the carbon off of it to repair it if it registers too much of a temperature change.
4. Replacing the EGR backpressure control valve.

 

Possible faults linked to P046C codes https://www.obd-codes.com/p046c

I'm away working all this week but as soon as I can, I'll update as this all seems to be a very common problem and my expensive learning curve may help someone else.

Regards

Rob