ChrisGoulding Posted October 29, 2008 Report Share Posted October 29, 2008 Having had a successful year without any starting problems, the time of year has now come around again where the car starts to struggle to start againdue to the cold weather. The car is a 2002 Audi A6 1.9Tdi. Glow plugs and coolant sensor have already been changed. The glow plugs are getting a current of between 10 and 11 volts for about 5 seconds when the outside temperature is only 2 degrees. The coil only stays illuminated for a second or 2. How long should the glow plugs be on for? 5 seconds doesnt seem long enough to get them hot enough. Link to comment Share on other sites More sharing options...
Tipex Posted October 29, 2008 Report Share Posted October 29, 2008 Have you tried cycling the ignition on and off a few times before cranking the engine? If you keep the ignition on till the glow plug light goes out, then turn the ignition off, and repeat a couple of times it'll get some extra heat into the plugs, if the car starts fine after that then there must be a faulty temperature sensor somewhere. Link to comment Share on other sites More sharing options...
ChrisGoulding Posted October 29, 2008 Author Report Share Posted October 29, 2008 How many times would you suggest? If I did 4 or 5 times that would equate to around 15 to 20 seconds. That should do it I would have thought. I will give it a whirl. Link to comment Share on other sites More sharing options...
Tipex Posted October 30, 2008 Report Share Posted October 30, 2008 I would have thought 2 or 3 times should be enough, but you should tell straight away if it fires up cleanly. I had this problem on a Mondeo, and a new temperature sensor fixed it, I'm not sure how different the system is on an Audi, but it must have some way of reading the temperature and adjusting the length of time the glow plugs stay on. Link to comment Share on other sites More sharing options...
ChrisGoulding Posted October 30, 2008 Author Report Share Posted October 30, 2008 I wonder if anyone one here has a graph/chart showing coolant temperature against time glow plugs should be on? Link to comment Share on other sites More sharing options...
ChrisGoulding Posted October 30, 2008 Author Report Share Posted October 30, 2008 I turned the glow plugs on for 4 times this morning, waiting around 5 seconds a time. Tried to start the car, but got the same result - the engine turns over for a few times and seems to struggle then starts up with a load of white smoke coming out of the exhaust. It has NEVER failed to start up, but always seems to struggle when it is cold. Link to comment Share on other sites More sharing options...
Tipex Posted October 30, 2008 Report Share Posted October 30, 2008 Ok, as you say the glow plugs have been changed, the problem probably isn't there. My next move personally, would be to change the battery, in cold weather you could be losing enough power to make it a bit of a struggle, modern cars are very sensitive to weak/ageing battery, it doesn't even have to be down by much and it can cause problems. Link to comment Share on other sites More sharing options...
ChrisGoulding Posted October 30, 2008 Author Report Share Posted October 30, 2008 Would the fact that the glow plugs are only getting around 11 volts be because of the battery? The voltage gauge reads around the 14 volt mark once the engine is going. Also, I did have the battery checked once before (about 10 months ago) and they said it was ok. Do you think it will be better to change it and at least that rules the battery out as being at fault. Link to comment Share on other sites More sharing options...
kite Posted October 30, 2008 Report Share Posted October 30, 2008 Could the pump timing be slightly out. I think the engine advances the timing slightly when its cold. Link to comment Share on other sites More sharing options...
Tipex Posted October 30, 2008 Report Share Posted October 30, 2008 It's the cranking voltage of the battery you need to measure, if you can afford to, I would just change it personally. Link to comment Share on other sites More sharing options...
ChrisGoulding Posted October 31, 2008 Author Report Share Posted October 31, 2008 Could the pump timing be slightly out.I think the engine advances the timing slightly when its cold. I took the car to a garage earlier today and he said that the fuel pump can not be adjusted as the car is too old. Is that right? It is only 6 years old. Link to comment Share on other sites More sharing options...
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