Help Please!!! MK3 Golf TD (AAZ)

[Alun]

My 1994 MK3 Golf TD (engine code AAZ) is having trouble starting from cold, it struggles to fire and put's out alot of heavy white smoke untill it's running (and then it's fine). I've narrowed it down to two things, either a pre-heating fault or low compression. The car has currently covered 155,000 miles so I can't see it having low compression, so that leaves the pre-heating system.

I've recently had the alternator reconditioned and the battery is only 2 years old, so all is fine there. Also, I can't see it being the fuesed relay because the glow plug warning light still illuminates (am I correct with that one?), and this leaves two things, the glow plugs or the glow plug control unit.


Can anyone give me a detailed description of where and what the glow plug control unit looks like? I know it's behind the dash just above the fuse box but I'm stumped and what it looks like.

Also, if it is the fuesed relay, where abouts is this located and what do I have to do to get at it?

One more thing, to fit new glow plugs, does the fuel pump have to be removed as this is directly infront of the first two plugs. I've looked in the Haynes Manual but it doesn't mention anything about removal of the fuel pump.

Help anyone please!!!

[Crasher]

Change the glow plugs as that is the most likely reason for the problem, but as you can see, they are a pig to get at for 1 and two. You can just do them without removing the pump but you need to remove the injector lines first. If you find the glow plug control unit (it has a56 printed on top) what are you going to do with it? They don’t ever seem to go wrong so I would not start with that. The 50amp fuse is above the relay plate as well. Have you had a fault code scan done? This is in group 41 "diesel pump on the AAZ, not group 01 engine.

[Alun]

Thanks! I think I'll try replacing the glow plugs first and see how it goes. I'll post up my findings in a few days.

Any other suggestions welcome!

[Alun]

Just an update really:

Fitted new glow plugs, combine that with a recent(ish) battery and a reconditoned alternator and the car starts like a dream! It was extremely frosty the other night coming out of work, the car was froze solid. However it still turned over 1st time on literally the first crank of the engine.

Having trouble starting your diesel on these cold mornings? Replace those three things and you can't go wrong (unless it's really knackered!)

[dubtastic]

lol I was having those symtems lately, blamed it on the choke...I'm a bit sheepish about changing the plugs...as I have heard stories that they might break inside when replacing them?

anyhoo how much are they and are they easy to replace? I havent changed them since I've owned it, its done around 89k and Ive just done under 9k in a year in my 94 td.

[Crasher]

I have only broken (well it wasn't me but one of my mechanics) one in 25 years and it was a git to get out but the two that will be evil are one and two behind the pump. Take the injection pipes off as a group to make the job possible. Even genuine VW they are only £13 each.

[Alun]

I got NGK plugs for just under £9 each, so just under £40 for the plugs. It was then another £40 to get them fitted. The car was in the garage all morning. And the injector pipes didn't have to come off, although it would prove usefull if you could get them off as otherwise it's extremely fiddlly trying to get the small nuts and bus bar thing back on! ( I watched the mechanic).

All in all, if you don't want to mess around it should cost you no more than £100 very maximum for a garage to do it for you.

Oh and the plugs are reletively small, I expected them to be quite long but they were actually quite short.

[dubtastic]

yay I was glad I searched this site last night and finding this thread. I purchased a set of glow plugs but at the same time I noticed one of my fuel lines was slightly perished and weeping so I changed all of those too! I managed to change them all with just one pack-£4.99.happy days. car starts up fine now. but to be honest the plugs were not in the most accessible of places, in fact they were a b#!ch to get to :banghead:. oh well...

Tip- I found using one of those magnetic pick-up tools essential during the fitting of the lil nuts...I magnetized the glow plug so that the nut would stick to it during fitting rather than dropping into the abyss :)

[Crasher]

And the injector pipes didn't have to come off

He must have long thin fingers!

[Alun]

He must have long thin fingers!

He used the same technique as mentioned above. He had a really long bendy stick thing with a magnet on the end, somehow weaved it through to the number 2 glow plug (which was the most difficult), managed to place the nut ever so gently on the screw end of the glow plug and then gently use a screw driver to turn the nut and get it to bite on the thread. Needless to say, this was not as easy as it sounds and required many attempts, most of them ending in obcenities! But it got there in the end.

I also replaced the fuel lines a few months ago as it was leaking fuel everywhere. I bought a roll of fuel line from Hlafords (£4.99) and replaced all of the material lines! Was very easy to do.

[dubtastic]

http://i85.photobucket.com/albums/k51/ukjoeuk/lilimag-1.jpg

I was enthusiastic enough to take a picture whilst fitting..It's a lil blurry but hey..