Leon Cupra TDi Glow plugs and harness

[leon_81]

Hi all,

I've searched and read a whole bunch of threads but I'm not any closer to working out what I need to do to fix my problem...


I've got a 2004 Leon Cupra TDi, and the Engine Mgt Light came on as a New Year gift!


A friend of mine has VAG-COM and read the codes and it showed glow plug cylinder 4 error


Looking on here it seems I may need a set of glow plugs, but also likely the loom/bridge



So last night I popped into Crawley Down Seat and asked for a price and they said I can't buy the glow plug loom, I have to buy the whole engine loom at a cost of around £350 + VAT!!!




At the weekend, I'm hoping to be able to have a look and see if I have the 2 or 4 wire loom - so is this an easy thing to spot or do I need to start stripping back loom wraps etc to see what I have?


Then once I've worked out which one I have - where do I go from there? Does anyone have part numbers for the new looms to splice in (both 2 and 4 wire options) so I can see if the dealer can help me out?



Thanks in advance!
Leon

 

[beezanick]

Why do you need a new loom? Cant you just replace the single (or all the) glow plug/s?

 

[leon_81]

From reading on here it seems the loom degrades and so probably needs changing

I'm not sure if it's worth changing the glow plugs first and seeing how I get on


I'm also more than a little concerned at the prospect of snapping a glow plug and ending up in an even worse situation!

 

[oldman]

just replace the glow plugs - all 4 for ease
if fault code comes back change the harness.

plenty of info in the tdi section complete with guides and part numbers

 

[leon_81]

I know there are a lot of threads on here - I mentioned that in my first post. It just seems that some conflict each other

I've ordered glow plugs and will hopefully get some time at the weekend to change them.


What I still need to know though is how to check whether my car needs the 2 or 4 wire harness/bridge - is it something I can see relatively easy, or do I need to start unwrapping looms?


Anyway, I think there are 2 possible part numbers (depending on which harness/bridge I need)

2 wire - 038 971 782 B
4 wire (with plug?) - 038 971 220 D


Can anyone confirm if that is correct? I'm going to as the dealer to check both part numbers later when I collect the glow plugs to see if they can get them. The reason for this is that they told me before that they can only get the whole loom at a cost of £350 +vat!

 

[leon_81]

Time for a quick update... I had a go at changing the glow plugs yesterday with minimal success.

I only actually managed to undo 1 of the 4 glow plugs (gearbox end) the other 3 seem to be mega tight and I can't afford any breakages at the moment, so decided to leave them


As for the harness/bridge, I think my car has the 4 wire version, I managed to pull back the loom wrap about an inch and could see at least 3 wires, all black but with a different colour stripe - can any one confirm that for me?


Does anyone have any suggestions regarding getting the glow plugs out without them breaking off? Will WD40 work if i give them a spray each day or is that pointless?


Thanks again!

 

[oldman]

mine is 04 tdi and you need 4-wire which has a plug on the end
this plugs in at the top right
you need to remove battery & airbox to follow existing cable

 

[leon_81]

Thanks - any ideas regarding getting the glow plugs out? Any special techniques to avoid snapping them?


Leon

 

[oldman]

no idea on that
i had garage to the plugs, i did the harness following a guide noted in another thread

 

[NagaBurns]

I changed my own glow plugs before Christmas after following advice on this forum and had no problems at all.
Make sure the recess that the plugs sit in are clean, you don't want any crap falling in the hole left by the removed plug or getting trapped in the thread of the new one.
Get the engine hot before you start. I did it straight after arriving home from work and loosened all the plugs first before the engine started to cool so I didn't have to rush. I didn't need to use any penetrating oil but from what I was advised it wouldn't matter if you did. Make sure you don't cross the threads on your new plugs, tighten them by hand as much as possible first.
Oh, and wear some gloves if you don't want to get burnt by the hot engine.

Hope it goes well for you.
All the best
Lee

 

[James_R]

I changed my own glow plugs before Christmas after following advice on this forum and had no problems at all.
Make sure the recess that the plugs sit in are clean, you don't want any crap falling in the hole left by the removed plug or getting trapped in the thread of the new one.
Get the engine hot before you start. I did it straight after arriving home from work and loosened all the plugs first before the engine started to cool so I didn't have to rush. I didn't need to use any penetrating oil but from what I was advised it wouldn't matter if you did. Make sure you don't cross the threads on your new plugs, tighten them by hand as much as possible first.
Oh, and wear some gloves if you don't want to get burnt by the hot engine.

Hope it goes well for you.
All the best
Lee

Its nice to see someone take advice in

good shout Lee.

 

[leon_81]

When I had a go at changing the plugs then engine was hot - I'd just got back from a half hour drive...

I checked to make sure there wasn't any dirt etc round the plugs too - but as I couldn't even loosen 3 of them that turned out to be the lease of my problems /



So, does anyone know if spraying with WD40 for a few days is going to help at all - or do I just need to go at them with a bit more force and keep my fingers crossed they don't snap?

I've been ill the last few days so haven't been out to have another go

Cheers
Leon

 

[donagh]

Just wondering how you got on, I have the same issue does changing all the glow plugs fix it?

 

[leon_81]

Still only managed to change 1 glow plug, 3 are well and truly siezed in - not sure what to do about it at the moment? I don't have the money to get it sorted if they snap, so will have to leave them for the time being.

I changed the glow plug harness/bridge at the weekend though, and a friend is going to plug it into VAG COM on my lunch break to clear the fault code - so I'll know over the next few days whether the wiring change has fixed it or not

 

[donagh]

Fingers crossed eh! Gonna try and get the bits at the weekend and get stuck in. Sure let us know if it was the harness/bridge

 

[Seatmann]

I think this guy might be nuts.

http://forums.tdiclub.com/showthread.php?t=267850&highlight=siezed+glow+plugs

You might find these useful

http://forums.tdiclub.com/showthread.php?p=749854

http://forums.tdiclub.com/showthread.php?t=66366

And a lot of these guys use penetrating fluid like wd40 to remove stuck plugs.

 

[James_R]

http://forums.tdiclub.com/showthread.php?t=267850&highlight=siezed+glow+plugs

HA! i like it!

 

[Seatmann]

I'm not sure if it's how I would do it but hey, each to their own.

 

[leon_81]

Well after replacing the harness a week ago and getting the fault cleared via VAG COM - I'm happy to report the light hasn't come back on - so all appears well (touch wood)

Not the easiest of jobs to do - but well worth having a go rather than paying dealer prices for labour

 

[oldman]

those were my sentiments leon 81
proud of them as well and after this long (no idea how long that is) still no error