3.0tdi glow plug light only on for 1 sec.

[sparker]

Hi,
I have a 3.0tdi allroad 2006, 50,000 miles. With the cold weather (first since buying the car) I have found that the glow plug warning light is still only staying on for about a second (or the same amount of time as it was staying on for in the warmer days). When it starts from cold it doesn't fire up on all cylinders immediately (but does always start) and unburnt diesel fumes come out off the exhaust. It's all fine after a few seconds off running. I assume this because the glow plug system is not working but wondered if anyone can give me a clue as to why not.

1, In the cold minus 1-5C, approx. how long should the light come on?

2, The light is not flashing or coming on at any other time, could it be water temp sender not working to tell the ECU its cold?

3, Are their any settings that can be changed or resets in the diagnostics to make it work?

Booked to go in to garage on Wednesday but don't want them to start replacing glow plugs etc. if they are not the problem and a simple fix can be found.

Many thanks

[Guest 2]

My 2008 3.0tdi's (51k) heater plug light only stays on for about a second from cold start. It starts perfect each time but sometimes the car would shake very slightly. I was told by Audi that my heater plugs were in good condition 3k miles ago.


Sent from my iPhone using Tapatalk

[AxeMurderer]

Don't panic about the light. I think that it only indicates that the glow plugs are getting up to temperature. This only takes a second or so even when it is properly cold. Then the light will go out, but the glow plugs will stay on for, I believe, a couple of minutes.

However, the light will go out after a second or so even if some of the glow plugs are not working. This has very recently been the case with my car. Even with 2 glow plugs not working, the car started and ran just fine.

Unfortunately this does suggest that the garage may need to replace some of your glow plugs.

[sparker]

Thanks for the reply, it seems my assumption that the light should stay on longer in cold weather is wrong and that the glow plugs need to be checked.
It's always good to have an idea of what might be wrong with a car before going to the garage, so thanks for the info.
I'll post to let you know the out come.

[sparker]

Hi,
Here is the update on the glow plugs.
I cancelled the trip to the garage instead deciding to take a look at them myself.
Tested all the glow plugs for resistance using a metre, all where OK bar one which had a closed circuit (or 0 reading).
Replaced this with a new Beru one. Lucky for me I found all the 1/4" drive tools I needed and a small torque wrench in my garage. While waiting for the part to arrive I had been spaying penetrating oil on said plug. Ran the engine to get some heat in it, then deep breath, I undid the plug using a little pressure with a T bar and it came out fine (scary thinking of the cost if it snapped but it all went fine, all done in 15mins). Total cost £18.00.
All seems fine now but need to try starting it again when left over night in minus temp to check it is really sorted.
Cheers again for pointing me in the right direction.

[Peter D]

Strange, as 0 ohms would blow the fuse. What were the values of the other glow plugs. Regards Peter

[sparker]

Strange, as 0 ohms would blow the fuse. What were the values of the other glow plugs. Regards Peter

Oh! As you might gather I'm no expert and I don't really now how my old non digital metre works. It has an adjuster wheel on it and I set that so the needle read 4 on one of the scales. (sorry I can't be accurate)
I checked all the plugs and all read the same value except one which didn't move the needle at all. I checked it several times to make sure I was making a good contact but the needle stayed completely still. Without altering the settings on the metre I also checked the resistance for the new plug and it was identical to the other 5 in the car.

So I can't give you an accurate Ohms reading for the working plugs but the readings where all same and the same as the new one.

I started the car after it had been sitting all day at -1 to -3 and it started perfectly. I'll try again in the morning.

Where are the fuses located for the glow plugs? Can't see them listed in the owners manual. If you think it might have blown them I would like to give them a check. If the fuses had blown would the glow plug warning light work?

Cheers

[sprocket25]

Hi, stick a volt meter across the plug connector and switch the ignition on to see if the supply is ok. My 3.0 tdi only comes on for a second and starts fine every morning even yesterday at -14. Hope this helps

Russ

[sparker]

Hi, stick a volt meter across the plug connector and switch the ignition on to see if the supply is ok. My 3.0 tdi only comes on for a second and starts fine every morning even yesterday at -14. Hope this helps

Russ

Thanks Russ,
Glad to here your car starts so well in the tuff conditions you have up in Scotland. It is impressive any diesel starts at -14. The anti freeze added to diesel must have improved a lot over the years, it used sludge up so it wouldn't even reach any glow plugs!
My car does seem to start up well now, since changing the one faulty plug(even if it is a bit 'wimpy' cold in the south)
If it gets colder and causes problems again I'll try what you suggest.

[gianton]

Same here, at -18c light came on for a second and then started with no problem. But I turned on the pre-heater for 15mins before, don't know if that makes any difference.