MK3 Golf TDI Glow Plug starting issues

[27motorhead]

I have a 97 MK3 Golf TDI and on certain occasions (normally when it's the most inconvenient!) when turning the ignition on the glow plug light sometimes refuses to come on. Sometimes it can take many attempts before it comes on and when it does the car starts fine.

Just before Christmas I was using the car early one freezing morning and it cut out several times within the 1st 5min of use. Mr. AA came along and he couldn't find anything wrong (I didn't expect him to and it had been idling for ½ hour to keep me warm!) so he followed me home and all was fine. He said something about diesel freezing up??? (I think I had filled it up last in early September) Anyway local garage couldn't find anything and no fault codes were generated. Each time it cut out the glow plug light refused to come on 1st time so not sure if it's connected to the above problem

I read a earlier post about the 109 relay which sounds like it could be that...

I've also just replaced the ignition switch which I thought could be the fault (after a bit of web searching!) but the glow plug light is still intermittent.

Looks like I'll take it into a garage - anyone know of any reputable ones around Sutton / Surrey area as I'm not originally from around here. Also would a VW dealership be best or is it a job for diesel / auto electric specialists???

I also have a beautifully machined steering column puller I made to replace the switch so If anyone’s ever after one you could borrow this one as they're a VW only tool (£££!!!)

Many thanks for reading!

Tim

[j_coupland]

Sounds like a faulty glowplug control unit. Do you know what your engine code is? I've got a 95 Mk3 Golf TDI and the engine code is 1Z. With yours being a 97 it could be one of the A series engines running at 110bhp. Anyway on the 1Z engine the glowplug control unit is part of the the cars engine management unit which can complicate things further! It could be the 109 relay as you said but it would probably be better if you can get a local VW dealer or an autospark to look at it. Hope this helps

[27motorhead]

Cheers for the reply!

As the weather has turned a tad nasty and I have HUGE amount of house renovation to do, the car will be going into a VW dealer tomorrow... only after numerous phone calls and being told they couldn't look at my car for 2 weeks!

Not sure on engine code, but will be interested to see what they come back with.

Hopefully they'll track it down and I'll post the findings which'll hopefully save someone else a lot of hassle and a lot of £££'s if it happens to their TDI.

Many thanks

Tim

[27motorhead]

Just a quick update...

Went to posh main dealer with the cleanest looking workshop I've ever seen... They had the car in for 3 days and they spent 10.5 hours on it!!! Thought it would be the ECU (£££!!!) but it ended up being some relay on the glug plug circuit - the mechanic / technician who was working on it wasn't in at 7.30am when I collected it so couldn't be told the exact part No. or VW code.

cost of part: £12.03

cost of labour: ££££'s!!! (Total bill came to about £520 inc VAT - they halved the labour as they felt sorry for me - normally £85 per hour)

So there you go... car is all fine now apart from the fact the the illumination light on the lighting control switch no longer works since it's been in!!!

Hope this will save some other person a HUGE expense.

Cheers

Tim

[Robbo100bike]

I have had the same problem, the engine cuts out in the cold and it take ages to get the glow plug light then it fires 1st time.

I have had it checked over to no avail.

Also Do you have to open drivers door and close it again, as stated in the owners manual??

[27motorhead]

Haven't even looked at my owners manual regarding this - never thought of looking! I have seen other peoples comments over the 'net that the glow plug light can come on when the drivers door is opened when the engine is idling / stationary. Not sure why though.

I also had a problem with the glow plug light coming on (repeated flashing) when the car got warm idling for some time and also during continuous motorway driving. This was caused by a faulty / or incorrectly adjusted rear brake light switch - strange but very true. You could prevent it flashing by just touching the brake pedal, but it would come on again about a minute later. Once I changed it this stopped!

Sorry - onto your cutting out / non starting - the non illumination of the glow plug started first. This happened very occasionally then got increasingly worse until one day I had the cutting out problem when cold combined with non starting / illumination of the glow plug light. This happened on several occasions which is when I did a bit of checking and took it to a local garage who couldn't find anything, so thought it was best to take it to a dealers (£££'s).

It turned out to be the glow plug control module relay at fault (approx £12 +VAT for VW one) so I assume it could be the same thing. As for not being able to find the fault - car electrics are a nightmare especially if intermittent and can be near impossible to fault find on your own. If I was you I'd change the above mentioned relay (sorry I don't have the VW code / part no.) and see if that helps - cheap enough and simple enough to do... I was worried it was going to be the ECU... BIG£££'s.

Hope this helps?!* Cheers! Tim

[Robbo100bike]

Don't suppose you have the part number for the relay? Might get it done on mine? (Stalled in petrol station had to wait 5 frustrating minutes before the glowplug light decided to work!!!)

[27motorhead]

Hi Robbo

Unfortunately I don't have the VW part number as the mechanic / technician wasn't about when I collected the car... I'm sure if you spoke to a Genuine VW dealer / parts place you'd be able to track the exact relay down - can't be many refered to as the glow plug control / module relay... and it's approx £12 + VAT .

Hope you can sort it out without having to pay out what I did!!!

Tim

[Robbo100bike]

I will try that thanks for your help.

I have started a thread about it being smokey from cold, if you have had any experience?????

Anyone any remedies for a smokey Mk3 Golf TDI (N reg). 155k!

It smokes badly from cold particularly at slower speeds and gearchanges, the smoke is blueish and rather annoying / embarassing. However once the car reaches operating temperature it runs clean. I have had it checked at a reputable general garage and they could find no faults.

I have tried letting it warm up for 5mins but the car doesn't seem to want to reach operating temp until it has been driven at 4th and 5th gear speeds for a reasonable distance. Sadly my commute is stop start fro the first 8mile which probably doesnt help.

Any suggestions appreciated

[philbrook]

check how much back pressure you have from cold at the filler cap see if that changes much when hot -i suspect it will.

in which case if its high could be rings == and i would rty the water injection method mentioned on the biodiesel forums thayt have had a lot of suc ess restoring compression