Seized Glow Plug - Cylinder 4

[59p]

Looking for some advice, had my engine management light come on last week when weather was a little colder than normal. Got around to plugging into VCDS and was presented with the following error code: 

 

497 - Cylinder 4 Glow Plug Circuit (Q13).... And some other text

 

Took the car to my local garage who confirmed it was defo a faulty glow plug however, the plugs would not budge and he didn't want to risk breaking them. Now the car starts and drives perfectly fine but I have this management light on even after clearing the fault! What are my options and is there a way of getting these seized plugs out? 

[KenONeill]

24 minutes ago, 59p said:

confirmed it was defo a faulty glow plug however, the plugs would not budge and he didn't want to risk breaking them.

Apply PlusGas, then leave overnight.

[59p]

7 minutes ago, KenONeill said:

Apply PlusGas, then leave overnight.

So mechanic sprayed some form of lubricant or wd40, left for a few hours.. Even took the car for a brisk 30min drive to get engine nice and hot but made no difference. 

[Crasher]

Removing glow plugs is a butt clenching experience, especially externally mounted ones, the Audi V6 CR TDI is especially nasty, often all six snap. When they do snap w have a specialist engineer come out and remove them.

[59p]

22 minutes ago, Crasher said:

Removing glow plugs is a butt clenching experience, especially externally mounted ones, the Audi V6 CR TDI is especially nasty, often all six snap. When they do snap w have a specialist engineer come out and remove them.

Do I carry on driving it until they all fail? It's just that if I come to sell the car, can't be advertising with the engine management light on.

[SuperbTWM]

Are you sure there isn't another underlying code causing the EML to stay on, in the past glow plug codes did not initiate the EML however they are important post starting for a clean burn so I can see their change in logic for modern diesels with DPF's etc.

 

I see you have no option really than to bite the bullet and change the faulty one, isn't an EML an MOT fail these days?

 

 

[59p]

4 minutes ago, SuperbTWM said:

Are you sure there isn't another underlying code causing the EML to stay on, in the past glow plug codes did not initiate the EML however they are important post starting for a clean burn so I can see their change in logic for modern diesels with DPF's etc.

 

I see you have no option really than to bite the bullet and change the faulty one, isn't an EML an MOT fail these days?

 

 

No its defo this as the code was cleared and then returned a few days later. I'd like to change the faulty one but its proving rather difficult to get it out lol

[SuperbTWM]

If you are prepared to give it enough force to snap it, it may just come out anyway. If it comes out in 1 piece or a thousand you don't really have many other options. How much do you trust your mechanic? 😂

 

If you are religous you could say a little prayer for it?

 

If it was me doing it I would try a low powered impact and give it some with that first to try and break any corrosion in the threads loose. It doesn't help that they are a tapered thread usually

Edited 13 October, 2022 by SuperbTWM

[Ecomatt]

I know they say warm the engine up but I have never done one on a warmed engine. With heat everything expands and so makes it tighter. Usually only a tiny bit of force is needed with a long bar. If it snaps it snaps.  It can be extracted out without a head off job. They are not torqued up tight but generally get stuck with the carbon and soot from the other end.

[langers2k]

When I did my glow plugs, I applied plusgas twice a day for about a week in advance. Both at night when the engine was cool and after a journey so the engine was hot. All four came out without issue 👍

 

They may have been free enough but it's certainly a low cost exercise to see if it helps.

 

[59p]

8 minutes ago, langers2k said:

When I did my glow plugs, I applied plusgas twice a day for about a week in advance. Both at night when the engine was cool and after a journey so the engine was hot. All four came out without issue 👍

 

They may have been free enough but it's certainly a low cost exercise to see if it helps.

 

Gonna give this a go.. Question though, were you glow plugs seized or did you attempt to remove before using the Plusgas? 

[langers2k]

I didn't even try and remove them prior to the plusgas. Given the horror stories and that I wasn't in a rush, it didn't seem worth it.

 

Car had ~120k miles and was 6 years old when I did it, plenty of time for them to have gotten stuck

[RoddersUK]

3 hours ago, langers2k said:

When I did my glow plugs, I applied plusgas twice a day for about a week in advance. Both at night when the engine was cool and after a journey so the engine was hot. All four came out without issue 👍

 

They may have been free enough but it's certainly a low cost exercise to see if it helps.

 

I've had to do this too, for caliper bleed nipples. Squirt on thread when I left for work, squirt when home, for a week. They came out in the end.

One squirt isn't always enough!

[J.R.]

7 hours ago, Ecomatt said:

With heat everything expands and so makes it tighter.

Incorrect.

 

Everything expands but at different rates according to their coefficient of linear expansion,a steel glowplug thread into an alloy cylinder head thread should get more clearance & hence loosen the more heat is applied but I am talking about local heating with an oxy-acetylene torch, 90° engine temperature isn't going to make much difference.

 

If the cylinder head has helicoil inserts for the glowplugs then heating might even be counterproductive.

 

I like the idea of an impact wrench, they can normally loosen stuck things but rarely have enough actual torque to shear a fastener. It could be used alternatively clockwise and anti-clockwise.

 

I've had air ones for decades but have only recently acquired a battery one, I have yet to use it on a rusted fastener so the proceeding was my gut feeling and not experience, perhaps someone experienced with them can confirm or deny?

Edited 13 October, 2022 by J.R.

[StevesTruck]

If it's just one, I'd personally leave it alone. The CR's don't seem to need a lot of glow, so the other 3 will get it going easily enough. 

[59p]

7 minutes ago, StevesTruck said:

If it's just one, I'd personally leave it alone. The CR's don't seem to need a lot of glow, so the other 3 will get it going easily enough. 

Agree and the car has been running fine with the 3 working plugs, however I have a EML on which is annoying to see every time I drive the car. 

[Cap44]

Why do people use WD40 when its Water Dispenser Formula no 40. Its useless as a penetrating fluid Plusgas every time.

[ords]

56 minutes ago, 59p said:

Agree and the car has been running fine with the 3 working plugs, however I have a EML on which is annoying to see every time I drive the car. 

Running fine or not, it will fail the MOT if the light is on.

[SuperbTWM]

1 hour ago, J.R. said:

 

I like the idea of an impact wrench, they can normally loosen stuck things but rarely have enough actual torque to shear a fastener. It could be used alternatively clockwise and anti-clockwise.

 

 

Depends on the bolt/stud but I would say you are more likely to pull the threads out of whatever the fastener it is in than shear it but it sure is possible with the lastest battery impacts these days, they are very impressive. I've got a Dewalt DCF899 and that is a beast, what i find more impressive though  is my tiny 3/8" drive 12V milwaukee which will take wheel nuts off and a lot of suspension bits etc. really handy because of its size and weight.

[StevesTruck]

15 hours ago, 59p said:

Agree and the car has been running fine with the 3 working plugs, however I have a EML on which is annoying to see every time I drive the car. 

 

Fair point. 👍

 

 

14 hours ago, Cap44 said:

Why do people use WD40 when its Water Dispenser Formula no 40. Its useless as a penetrating fluid Plusgas every time.

 

Same reason people post criticising everytime someone mentions WD, we've all got our own ways of doing things. Personally I start with some 99p a can stuff and if that doesn't work, use something better. 

[SuperbTWM]

4 hours ago, StevesTruck said:

 

Fair point. 👍

 

 

 

Same reason people post criticising everytime someone mentions WD, we've all got our own ways of doing things. Personally I start with some 99p a can stuff and if that doesn't work, use something better. 

 Lets not kid ourselves, it doesn't matter what you use, the penetration is always minimal and usually does very little apart from making you feel like your helping matters.

[KenONeill]

3 hours ago, SuperbTWM said:

 Lets not kid ourselves, it doesn't matter what you use, the penetration is always minimal and usually does very little apart from making you feel like your helping matters.

I presume you've never used a proper dismantling lubricant.

[J.R.]

3 hours ago, SuperbTWM said:

Lets not kid ourselves, it doesn't matter what you use, the penetration is always minimal

 

I could never bring myself to use an extender 😆

 

Plus gas used to give me a real buzz as a youngster when I sniffed it, it could probably have put me into an  ethylic coma, like all the modern substitutes what is sold now is probably not a patch on the real deal and they really should stop them selling it under the brand name and just label all stuff like that "ineffective shoîte" 😆

 

[ApertureS]

13 hours ago, SuperbTWM said:

 Lets not kid ourselves, it doesn't matter what you use, the penetration is always minimal and usually does very little apart from making you feel like your helping matters.

That’s because people use wd40 which is useless… and is a ‘perfect product for nothing’ when there are products that do what they claim a million times better but on the downside of not doing everything in one can

 

a mix of cheap power steering fluid and acetone works wonders and another one I enjoy is getting the bolt/nut red hot and dabbing in with a candle, the paraffin wicks down the threads and helps a tonne.

[59p]

Well ordered some PlusGas, will give this a blast over the coming days to see if it free's up the glow plug.