2.5 tdi glow plugs?

markyzs180

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Are they difficult to change??

Noticed as the morning have got colder the old bird is taking a few glow cycles to start up and even then it can be with a bit of a splutter so am assuming glow plugs?

Haven't had the engine cover off to have a nosey (too dark at 5am lol) so thought I'd pull on the vast knowledge of you guys so I know roughly what to expect!!

Thanks in advance.... :thumbsup:
 
Clearly our cars are conjoined twins separated at Ingolstadt! I was going to post this very same thread this weekend!

On the plus side they are only about £12 each, which isn't too bad ....
 
James...not liking the sound of this job already! Just found this elsewhere...

" I have a '98 A6 with the 2.5 V6 TDI engine, with about 150,000 miles on the clock.

For some time, the engine has been difficult to start from cold, requiring several seconds of turning-over before it starts to catch. I have to continue to crank the engine for a further 1/2 second before enough cylinders are firing for the engine to run properly. There is often a brief cloud of whitish smoke after the engine fires. Once running, the car performs fine and it starts from warm perfectly.

All but 1 of the glow plugs are the original factory fitted items so I am considering getting all 6 renewed to try and improve starting.

However, my local (non-franchise) VW/Audi specialist is not particularly keen to replace the glow plugs on this engine as they have had several instances where they have snapped while trying to remove them, which then becomes a major job to drill out the plug.

Can anyone tell me
a) is it definitely worth changing all 6 glow plugs at this mileage as preventative maintenance? (i.e. is it likely to improve my starting problem)
b) does anyone know any 'tricks' as to how to get them out in one piece"



Gulp.....!!
 
When I had the first of my recon. engines, the garage took the plugs out of my original engine and swapped them with the replacement engine as I knew they were good. They all came out ok then, I will speak to the garage and see what they say.

I'm not sure that would have been the AKE engine in 1998 would it?
 
I would get someone with full VCDS to check the timing for you as i suspect the timing is out on your engine. If the glow plugs are burnt then you need to get them out but make shure you soak them in plus gas for weeks before atempting and make shure the engine is HOT. Use a stubby ratchet and if it does not come easy dont force-it. I have broke one last summer and i wont replace them unless really necessary.
 
would the pump timing really only become this apparent now the weather is cold? its fired up fine before the current cold snap? g12 temp sensor was changed in the summer so doubt its that, car is 6 years old on 100k so presume its still on original plugs which is why i assumed it to be them.....
 
You'll be fine changing these guy's. Just take your time and do them up by hand when putting them back in, then tighten with ratchet.
 
The plugs are only needed at temperatures of less than 5Celsius so they tend to last quite long. Bad timing could manifest in many ways, ussualy the engine is loud if too advanced and quiet but smokey if too retarded. The advance solenoid can adjust the timing quite a lot but only after the engine has started... These symptoms could point to a failing injector pump as well...
 
You'll be fine changing these guy's. Just take your time and do them up by hand when putting them back in, then tighten with ratchet.
Not an v6 tdi you wont ! They are thin and I have snapped one in the head wich required drilling out and helicoiling the head(wich did not hold) and ended up buying a new head afterwards... I also work on the v6 engines on a regular bassis and i own 3 v6 tdi VAG diesels.
 
I also work on the v6 engines on a regular bassis and i own 3 v6 tdi VAG diesels.

:applaus:

well if that's the case you must be an expert on these engines! So what advice would you give Mark and James then for changing them ?
 
I would get someone with full VCDS to check the timing for you as i suspect the timing is out on your engine. If the glow plugs are burnt then you need to get them out but make shure you soak them in plus gas for weeks before atempting and make shure the engine is HOT. Use a stubby ratchet and if it does not come easy dont force-it. I have broke one last summer and i wont replace them unless really necessary.
I just posted this earlier... Lots of plusgas and hot engine and even then they snap...Best to check timing first as the v6 engine starts ok in cold weather even without working glowplugs as long as the compression is within spec. At 0 celsius the glow plugs stay on for less than 5 sec wich is not enough to heat the cylinders...
 
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Penetrating oil much thinner than wd40. Gas engineers use it when freeing fittings off the gas pipes(elbows and tees,etc.).
 
Penetrating oil much thinner than wd40. Gas engineers use it when freeing fittings off the gas pipes(elbows and tees,etc.).

thanks for your advice on this, much appreciated :thumbsup:

can i just clarify one thing, when we talk about 'timing' we are talking about pump timing rather than engine timing????
 
This all sounds an ****. I'm pretty sure my pump timing is ok as it was fully set with Vag-com in March when the engine was swapped. Like Mark says it starts and runs fine when its warm, s I expect it's the glowplugs. I might get it checked to be sure, even so I don't think I have the courage to do it myself as I've had enough four figure bills already this year :sadlike:

Probably be the pump on the way out knowing my luck :crying:

can i just clarify one thing, when we talk about 'timing' we are talking about pump timing rather than engine timing????

Yes mate.
 
Probably be the pump on the way out knowing my luck :crying:


Ha ha ha, yes James and with your luck you'd only find that out after you had snapped all of the glowplugs trying to get them out and the bonnet had fell on your head.........then it would all happen to me :lmfao:

I can see what your saying about the timing, I've never checked mine so may well be a possibilty.....seriously think I need to buy myself VCDS.....
 
I'm having similar problems. I've booked in at the garage for them to run a diagnostic.
I tending to think its going to be the pump timings rather than the glow plugs.
If the pump timing is out is it an easy fix or does it mean that the pump is on its way out or something else?
 
at minus 3 -4 degs, I'm seeing the glow-plug light staying on for about 2-3 secs longer than usual and it's taking a couple of false-starts before it takes properly.... but it's been 100% fine after that.... I guess I'll try leaving it a few seconds longer before turning it over next time: it took about 5 goes when it was -7C.... definitley had me a little worried...
 
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Is your coolant temp. sensor working properly ? You can check it with vag com in measuring blocks... At minus 5-7 celsius, my glowplugs stay on for about 5-6 sec(the light go off) but they still on another 5-10 sec. to aid smooth running...you can feel the load off the alternator when they go off(similar to switching off AC). You could try disconecting the CTS and see if it starts well- then the sensor is duff or a few glowplugs are shorted. Pump timing needs checking as the belts stretch after a while thus trowing the dinamic timing off. If you have full vcds you can check that too...
 
You'll be fine changing these guy's. Just take your time and do them up by hand when putting them back in, then tighten with ratchet.

I 2nd this statement, i did all 6 of mine with 2 cups of tea and chocolate biscuit in my left hand, i used a bit of wd40 to start with sprayed around them, left it for 5 mins to soak in, came back and out they came and i put the new ones in with a dash of wd40 on the threads and in the went buy hand until it was time to tighten them up with a socket, then Roberts your dads brother,
 
I 2nd this statement, i did all 6 of mine with 2 cups of tea and chocolate biscuit in my left hand, i used a bit of wd40 to start with sprayed around them, left it for 5 mins to soak in, came back and out they came and i put the new ones in with a dash of wd40 on the threads and in the went buy hand until it was time to tighten them up with a socket, then Roberts your dads brother,
I had one break in the head and that was in the summer and with the engine hot and using penetrating oil ! I tell you that its a job best left to a garage to sort out IF a glow plug breaks in the head... You were one of the very lucky ones...
 
I had one break in the head and that was in the summer and with the engine hot and using penetrating oil ! I tell you that its a job best left to a garage to sort out IF a glow plug breaks in the head... You were one of the very lucky ones...

if one broke in the head then id be :scared2: and then :undwech: and my wife would do :applaus: and show me the :rulez: and id be sent out for :sos: and left outside in the :cold: until :iagree: ed to take it to :kissmyrings:
 
have just dropped off my car at the garage, he seems to think that if the pump timing is out then the pump is knackered. Is this right?
 
just heard back from the garage and there are no faults on the diagnostic. Seeing as its only going to be a very slight problem turning it on in the morning for another month or so I think I'll leave it and maybe test the plugs myself when its a little warmer.
Its not doing my engine any harm having to turn it over 5 or 6 times is it?
 
have just dropped off my car at the garage, he seems to think that if the pump timing is out then the pump is knackered. Is this right?

from what i've read the pump timing can be checked with vag-com and then adjusted on the engine and rechecked with vag-com....there is a thread about it in the diesel section, can't find the link to it at the moment...
 
just heard back from the garage and there are no faults on the diagnostic. Seeing as its only going to be a very slight problem turning it on in the morning for another month or so I think I'll leave it and maybe test the plugs myself when its a little warmer.
Its not doing my engine any harm having to turn it over 5 or 6 times is it?

may well be the timing then, they need to go into tdi graph to check it...have a search in the diesel section...
 
Come back from the garage a little miffed, he basically said that if the pump timing was out then the car would drive like a bag o'***** which it doesn't. there are no faults showing but it still has the problem with cold starting. I asked about the tdi graph but he insisted that the pump timing was not out. I wasn't really keen to fork out for a full set of glow plugs as I don't think this engine needs them and should start 1st time without them like it always used to no matter how cold. I'll probably have a go at removing and testing the glow plugs when it gets a little warmer. Is there anything else it could be or does it just need some new glow plugs?
 
ran a scan on mine and brings up nothing about glowplugs or timer etc

will try and run the timing graph tomorrow, let you know how it goes...
 
You need to have the engine hot at 80 celsius. The plotted line should be above the blue line and slightly under the green line. Make shure you have the right Tdi plugin for the v6 tdi. A old battery/lazy starter could also levy a hard start. I the timing is slightly out it will still run but it will be difficult to start.
 
You need to have the engine hot at 80 celsius. The plotted line should be above the blue line and slightly under the green line. Make shure you have the right Tdi plugin for the v6 tdi. A old battery/lazy starter could also levy a hard start. I the timing is slightly out it will still run but it will be difficult to start.

Thanks for the info, don't suppose you know which way to twsit the pump for advance/******?? or is it a case of mark n go ??? lol
 
You turn the pump clockwise to ****** and anticlockwise to advance. Small increments make big difference. Mark it with typex first.
 
If its frosty out, I give my glowplugs three goes before starting up, and it usually fire's within a turn or two. To my mind if that happens it shouldn't be the pump timing.