Glow plug warning light flashing

[KeithLewis]

Hi all, any idea why the the the glow plug warning light should start flashing and put the car into a limp mode, its a 2012 2.0 Ltr diesel

[b1ackb1rd]

Get yourself comfortable. Pour yourself a beer. And hit the search button ...

You may be here a while. 

[Trevor M]

Better still, also have a friendly Briskodian (is that the correct term,) read the error codes, as searching will give you several possibilities, many of which will not be the cause, and the error codes should at least point you in the right direction.

[Austin 7]

Hi Keith

 

The glow plug controller monitors the health of all 4 glowplugs. If any of them draw too much or two little current (e.g they have failed open or short circuit), a fault code will be logged and the glowplug warning light will flash.  Depending on the age and emission standard of the engine, the glowplugs may be used during the running stage of the engine as well as for cold starting.  It's possible that a fault would therefore be deemed serious enough to trigger limp mode to protect the engine.

 

VAG may also have decided to use a flashing glowplug symbol to indicate another fault, but I have no documentation to support this.

 

As said above, the first step is to get the fault codes read.

[skomaz]

From memory the glow plug light will also come on on some old models if the brake lights are not working as well - it did on our Fabia (I doubt that is your issue but hey it might be worth a check...)

[Urrell]

On 04/10/2021 at 08:27, Austin 7 said:

If any of them draw too much or two little current (e.g they have failed open or short circuit), a fault code will be logged and the glowplug warning light will flash. 

The glow plug light did not come on at all when mine failed, just the engine fault light.

[Frenchtone]

I think there is an O2 sensor on the top and behind somehting on the left of the engine, that causes the glowplug lamp to light when it fails  whats the mileage? I was informed anything over 80k and it can happen!

[Creakingjoints]

Hopefully not bad news for you, but the glow plug warning light is something of a pas partout which can include the EGR valve. Just had one replaced a few weeks ago due in all probability to too many short journeys. A 66 plate 2.0 diesel 4x4 has to have the front subframe dropped to get to the damn thing, All in all 8 hours job with subsequent 4 figure bill.

[aubrey]

Scan it with VCDS, that takes all of 5 minutes and will give you far more information.

[Delphi17]

The first couple of cool days we had brought on the warning light on my `15 4x4 140 diesel. A scan indicated cyl 2 & 3 heater plug fault,replaced all 4  anyway which took 20 mins .Job done no more warnings.2 & 3 did test out as duff .

Hth

[Stingray30]

Hi Guys . i know not my post. but having glow plug issues. senor came on for glow plugs and goes into limp mode as soon as accelerator pressed. mechanic changed glowplugs and still wouldn't go off so thought it be sensor. tried 3 different sensors and still same issue. any ideas? 

[Trevor M]

You need to get someone to check for error codes. The glow plug light does not necessarily mean any glow plugs are faulty. Also, glow plug failures do not normally cause a 'limp mode' situation.

Edited 16 January, 2022 by Trevor M

[freedie]

A flashing glow plug warning light is a sign of an engine management fault. Any dealer/VCDS user should be able to help. Good luck.

[Stingray30]

Mechanic had on computer. And reset all errors. Could see anything wrong. He baffled that light keeps coming on. What best and worse outcome would you guys suggest 

[KeithLewis]

when my glow plug light came on the car went into limp mode, I had to have a new manifold fitted. been ok since

 

[Stingray30]

Cheers Keith.  As u said mechanic baffled and had to leave it as was holding him back from his other work. Will give him shout tomorrow 

[b1ackb1rd]

My CAYC tdi used to go into limp mode at around 2k rpm when I first bought it, it was a London car and was never driven any great distance.

 

Turbo vanes were seized, 'throttle valve' in the intake totally sooted up, EGR blocked and soot in the DPF at 100% according to VAG DPF ... I also found many perished vacuum pipes; turbo activator, and a couple of modules that deal with overboost and the EGR activation. 

 

Pipes replaced, LOTS of goo put thru the tank, EGR spray (Revive), good fuel, a deft hand on the ignition switch when it kicked into limp mode to cycle the ignition and a regular smacked bottom on the bypass using as many revs as possible ... and 6 months down the line I can now rev to the red line, roll the throttle in high gears and fuel economy is now 40's (up from high 20's on purchase).

 

Final repair will be a new injector this week. 

 

All of the above separately and in conjunction with the other problems all activated the glow plug light and limp mode.

 

It's not usually a simple one-repair solution. 

[Urrell]

1 hour ago, b1ackb1rd said:

Final repair will be a new injector this week. 

That'll hit the wallet!

[b1ackb1rd]

1 hour ago, Urrell said:

That'll hit the wallet!

 

I know 😞

I have no choice, one injector is massively over fuelling, and it sounds like it's running on 3 when regenerating. 

[Urrell]

2 hours ago, b1ackb1rd said:

 

I know 😞

I have no choice, one injector is massively over fuelling, and it sounds like it's running on 3 when regenerating. 

Can they not be reconditioned ?

[Stingray30]

Guys update on car. Mechanic had it 7 weeks at his yard. He said evening was pointing towards actuator.  I got one on ebay for him but it only working for about a mile. ....New one was costing £200. He said it might not guarantee fault. He put old actuator back as I was send part back and the car drove for bout 30 mile then glowplug lights came on again. I've took car back now as he baffled and doesn't look what to do. Now looking a second opinion 

[Urrell]

42 minutes ago, Stingray30 said:

Guys update on car. Mechanic had it 7 weeks at his yard. He said evening was pointing towards actuator.  I got one on ebay for him but it only working for about a mile. ....New one was costing £200. He said it might not guarantee fault. He put old actuator back as I was send part back and the car drove for bout 30 mile then glowplug lights came on again. I've took car back now as he baffled and doesn't look what to do. Now looking a second opinion 

The glow-plug light covers numerous faults, when my glow-plug failed it did not bring up that light.
Has your mechanic not plugged in a fault code reader, that should be the first thing to do.

[Stingray30]

Yes he did. He changed glowplugs, sensors. Boost valve  and few other things. Cant remember exactly what he said. He just said he lost now. Hopefully 2nd opinion will help. Would it be possible loose wire or something simple?

[Urrell]

5 minutes ago, Stingray30 said:

Yes he did. He changed glowplugs, sensors. Boost valve  and few other things

Then he obviously did not read the fault codes, just changed what he thought it may be, you've been taken for a ride.
Ask him what fault coded were cleared and what the Ohm readings were for the glow-plugs he took out.

Edited 26 February, 2022 by Urrell

[Stingray30]

8 minutes ago, Urrell said:

Then he obviously did not read the fault codes, just changed what he thought it may be, you've been taken for a ride.
Ask him what fault coded were cleared and what the Ohm readings were for the glow-plugs he took out.

My mate bringing me a device for reading code.  Dont know how good it is but ill let you know. Any advice be much appreciated