How to replace glow plugs?
 

Hey does anyone know how to replace the glow plugs on an ASB engine please..

thanks

Be warned, this can be difficult as they can be seized.
I would suggest using a good knowledgeable mechanic that you trust.

On my old 2004 D3 which was an ASB engine code, I had a duff plug that wouldn't come out.
The garage tried all the usual heating, sprays etc but were reluctant to go any further than a particular torque wrench setting to remove it.
If it snapped, it meant removal of the head to drill it out etc. ££££
I left it and went with 5 working glowplugs for the last 2 years I had the car.
It always started fine with 5, slightly rough starting for 1-2 minutes on a very frosty morning which didn't bother me.
I used an auto electician to disable the flashing glowplug light in the dash as it was very annoying.
Hope you don't have such hassle with yours.

No i don't have any starting issues despite having only 4 working glow plugs but i have been advised to get them changed as soon as possible.

Currently i only have error codes stored in the engine ecu but it doesn't throw a CEL light on the dash or anything as such.

-------------------------------------------------------------------------------
Address 01: Engine Labels: 059-907-401-ASB.clb
Part No SW: 4E0 910 402 G HW: 4E0 907 401 D
Component: 3.0L V6TDI G000AG 0030
Revision: --H05--- Serial number: AUX3Z0I8368880
Coding: 0011973
Shop #: WSC 00046 000 00000
VCID: 20486A13F3B9134438-8074

3 Faults Found:
005661 - Glowplug for Cylinder 4 (Q13)
P161D - 001 - Open Circuit
Freeze Frame:
Fault Status: 01110001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 154496 km
Time Indication: 0
Date: 2018.02.23
Time: 08:01:04

Freeze Frame:
RPM: 945 /min
Torque: 156.0 Nm
Speed: 0.0 km/h
Duty Cycle: 1.0 %
Voltage: 13.15 V
Duty Cycle: 24.1 %
Temperature: 0.9°C

005662 - Glowplug for Cylinder 5 (Q15)
P161E - 001 - Open Circuit
Freeze Frame:
Fault Status: 01110001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 154496 km
Time Indication: 0
Date: 2018.02.23
Time: 08:01:04

Freeze Frame:
RPM: 945 /min
Torque: 156.0 Nm
Speed: 0.0 km/h
Duty Cycle: 1.0 %
Voltage: 13.15 V
Duty Cycle: 24.1 %
Temperature: 0.9°C

Readiness: 0 0 0 0 0

-------------------------------------------------------------------------------

There is a special (ie expensive) machine which can extract broken plugs without removing the heads. Might be worth calling round some diesel specialists to see if they have such a thing, and take it there rather than trying to diy it.

Oh the irony....

I'm expecting a visit from a mobile mechanic with such a special machine next week to rescue my 4.2 Tdi

On the plus side, they are quite easy to access, unlike some engines.


4 glow plugs reporting as faulty in the ECU.

Really poor cold weather starting (unsurprisingly)

Decided to swap all 8 (regret that now tbh)

4 swapped over ok.

1 has disintegrated shearing off the head completely and leaving the tail stuck in the head, although technically the head is still sealed which is sort of a bonus.

1 came out ok but has totally mashed all the threads (not so good)

1 is unscewed but refuses to come out (and we're reluctant to force it)

1 is unfeasibly, self destructively tight.



We did eventually find one guy who seems to make a healthy living from doing nothing else than recovering diesel blocks with stuck glow plugs and injectors.

If you're going to do it, lubricate the hell out of the things first, but that's very little guarantee of success it seems. Take it to someone you trust to (a) do it right and (b) sort it out if it goes badly.

Or (c) Buy a petrol lol :)

Jeez. Knew this wouldn’t be an easy job, but didn’t realise it would be quite the issue it is.

Can penetrating oil be applied well in advance? Have you seen those tools that rapidly heat up nuts and bolts? Like a kettle element crossed with a mig welder? I’ve seen those used to great effect on old car restorations. Wonder if that process could be adapted/used...

Edit: the tool is a commercial heat induction jobbie.

P.S. I think I’m right that glow plugs in TDi’s are used all the time the engine runs, not like they used to be on older diesels. What if anything, happens if you have a plug not functioning when driving? My sister’s C6 A6 four pot has had a faulty glow plug since she bought it a while ago. Starts and drives fine.

You're halfway right ^. The heat element is used for start, and some afterglow when its cold. In most commonrail engines the glow plugs are also used to measure the pressure in the cylinder:

http://beru.federalmogul.com/sites/d...sg_neu_web.gif

1 Plug
2 Circuit board with electronics
3 Glow plug body
4 Glow plug heating rod
5 High voltage connection
6 Measuring diaphragm
7 Gasket

There are a few articles on using the glow plugs to measure ionic conductivity of the combustion process, but it seems the pressure sensing is what the OEMs settled on.

An induction heater might loosen the plug if you can get it in there - thats worth a try if you can borrow one :)

Ha. Thanks for the clarification.

So I’m halfway wrong too....

I was halfway wrong as well! Ion sensing was proposed, but it seems no one has put in to production, preferring pressure sensing instead which much be close enough but cheaper. See the edited version for the correct info +++

A8 TDI Glowplugs seem to extremely prone to failure. The Service History indicated that my D3 had all 6 replaced twice over a 5 year period before I bought it. Over the next 5 years that I had it, almost all were replaced again and some of them twice.