EGR valve question

PauloMN

Ok long story short - car hasn't had much use over the past few months, in fact it's been mainly moving it on and off the driveway so as I can get my classic in and out of the garage. The car is a 2012 Audi A5 2.0 TDi, around 170k km.

So was out last week and the coil light started flashing, power dropped, like no turbo. No engine light. Went out a couple of days later, started fine, no lights, drove for a bit and then coil light started flashing, this time also the engine light came on, so I had a code to read. I've a simple code reader which shows P0403 EGR Flow Circuit Malfunction.

Had a look at the connection just to make sure there was no obvious issue there (there isn't). Also checked the vacuum unit to make sure it's not stuck, it isn't, I can move it from underneath but I don't know how easy it should be to move, it's stiff enough to move.

Anyway went out tonight again, and the coil light came on after about 10 mins, no engine light. Turned off car and restarted, went for a long drive giving it plenty of welly, probably the longest drive in months, and no lights came on again for the rest of the journey, and the car performed fine.

My question is - did it just need a good run, to properly warm up the car and maybe clear out some carbon deposits? I presume all the start up and moving the car around in cold weather whilst not giving it a good drive wouldn't help, esp with a diesel. I'll keep an eye on it anyway but would rather not bring it to a garage just yet if it just needed a good run.

Toyotafanboi

They'd be partial to an EGR in all fairness. Chances are, i'd say.

BlakeS94

PauloMN wrote: »

Ok long story short - car hasn't had much use over the past few months, in fact it's been mainly moving it on and off the driveway so as I can get my classic in and out of the garage. The car is a 2012 Audi A5 2.0 TDi, around 170k km.

So was out last week and the coil light started flashing, power dropped, like no turbo. No engine light. Went out a couple of days later, started fine, no lights, drove for a bit and then coil light started flashing, this time also the engine light came on, so I had a code to read. I've a simple code reader which shows P0403 EGR Flow Circuit Malfunction.

Had a look at the connection just to make sure there was no obvious issue there (there isn't). Also checked the vacuum unit to make sure it's not stuck, it isn't, I can move it from underneath but I don't know how easy it should be to move, it's stiff enough to move.

Anyway went out tonight again, and the coil light came on after about 10 mins, no engine light. Turned off car and restarted, went for a long drive giving it plenty of welly, probably the longest drive in months, and no lights came on again for the rest of the journey, and the car performed fine.

My question is - did it just need a good run, to properly warm up the car and maybe clear out some carbon deposits? I presume all the start up and moving the car around in cold weather whilst not giving it a good drive wouldn't help, esp with a diesel. I'll keep an eye on it anyway but would rather not bring it to a garage just yet if it just needed a good run.

By coil light are you talking about the glow plug light? If its flashing I would presume theres an issue with one or more of your glow plugs

PauloMN

BlakeS94 wrote: »

By coil light are you talking about the glow plug light? If its flashing I would presume theres an issue with one or more of your glow plugs

Glow plug light, yep. From what I read, it can signify one of a number of electrical faults, not just glow plugs. Engine code is giving an error on the EGR circuit.

alan partridge aha

Bought 2012 Octavia TDI 1.6cr in skoda dealership in December. Was driving on motorway coil light started flashing and loss of power. Off/on with engine everything grand for 20 miles then happened again.

Rang them after Christmas they said drive it maybe won't happen again. Must have done 150 miles but it did happen again. Diagnostic check by them revealed egr issues and needed replacement.

Covered under warranty thankfully. In totally it came on at least 7 times, but engine management light never did.

Moanin

PauloMN wrote: »

Ok long story short - car hasn't had much use over the past few months, in fact it's been mainly moving it on and off the driveway so as I can get my classic in and out of the garage. The car is a 2012 Audi A5 2.0 TDi, around 170k km.

So was out last week and the coil light started flashing, power dropped, like no turbo. No engine light. Went out a couple of days later, started fine, no lights, drove for a bit and then coil light started flashing, this time also the engine light came on, so I had a code to read. I've a simple code reader which shows P0403 EGR Flow Circuit Malfunction.

Had a look at the connection just to make sure there was no obvious issue there (there isn't). Also checked the vacuum unit to make sure it's not stuck, it isn't, I can move it from underneath but I don't know how easy it should be to move, it's stiff enough to move.

Anyway went out tonight again, and the coil light came on after about 10 mins, no engine light. Turned off car and restarted, went for a long drive giving it plenty of welly, probably the longest drive in months, and no lights came on again for the rest of the journey, and the car performed fine.

My question is - did it just need a good run, to properly warm up the car and maybe clear out some carbon deposits? I presume all the start up and moving the car around in cold weather whilst not giving it a good drive wouldn't help, esp with a diesel. I'll keep an eye on it anyway but would rather not bring it to a garage just yet if it just needed a good run.

Did it have the Nox Software update by any chance?

My A6 did and acted the same as yours and required a new EGR valve (Done under warranty thankfully)

alan partridge aha

Moanin wrote: »

Did it have the Nox Software update by any chance?

My A6 did and acted the same as yours and required a new EGR valve (Done under warranty thankfully)

As mine had the fix done as well. I didn't know but there was a code written in service schedule and found out it was the fix.

PauloMN

Moanin wrote: »

Did it have the Nox Software update by any chance?

My A6 did and acted the same as yours and required a new EGR valve (Done under warranty thankfully)

Yep it had the update done a couple of years back.

Had it out for about 30kms today, no problems again, I'm wondering did it get choked up with the short journeys and just moving it on and off the drive recently. Will keep an eye on it but no lights at all or power drops today, running fine.

corks finest

alan partridge aha wrote: »

Bought 2012 Octavia TDI 1.6cr in skoda dealership in December. Was driving on motorway coil light started flashing and loss of power. Off/on with engine everything grand for 20 miles then happened again.

Rang them after Christmas they said drive it maybe won't happen again. Must have done 150 miles but it did happen again. Diagnostic check by them revealed egr issues and needed replacement.

Covered under warranty thankfully. In totally it came on at least 7 times, but engine management light never did.

AFAIK the egr can be cleaned or am I totally getting it mixed up

alan partridge aha

Not sure about that, I've read its not usually a success on some forums but this could be wrong.

corks finest

alan partridge aha wrote: »

Not sure about that, I've read its not usually a success on some forums but this could be wrong.

On my Honda forum supposed to be easy

alan partridge aha

Well ita apparently a bit of a job to get the valve out of 1.6 vw.

corks finest

alan partridge aha wrote: »

Well ita apparently a bit of a job to get the valve out of 1.6 vw.

I haven't a clue tbh but my particular forum (insight central) Honda insight, has saved me hundreds of euros 💶 over the years, and I'd advise any car owner to join whatever car forum is relative to them

PauloMN

alan partridge aha wrote: »

Well ita apparently a bit of a job to get the valve out of 1.6 vw.

Yep, on mine apparently it's easy to get at the part because of the way the engine is mounted, but the part itself is expensive.

On other cars the EGR valve is behind the engine and is more hassle to remove.