Audi a4 B5 2.5tdi Starting Issue
My car is having trouble starting in the mornings when it has been left for 4 hours or more, it starts up with a load of un burnt fuel (you can smell it), fine when hot.
I have done a few tests.
First test was to check the battery voltage first thing in the morning which was at 12.6v even though the battery is 4 years old.
Second test was to make sure all glow plugs has a resistance of less than 5ohms; all did bar two, so I have changed them.
Third was to make sure voltage was getting to all the glow plugs, I remove the temperature sensor connector to make the glow plugs stay on longer, I did this on all six connections and was around 11.5v mark which from what I read on the internet was fine. The temperature sensor was changed 3 years ago when I had hot starting problems.
Fourth I have changed the fuel filter, people on the internet were talking about the O-ring but I am not sure were that is supposed to be because when you disconnect the T connector that is held in place with an R clip the plastic bit when you look inside has no rubber O-ring inside I have tried to get an idea of what it looks like but I am struggling with that. If some could post an image of what it should be would be great.
The last test I did was to disconnect the coolant temperature sensor to make it think it was really cold outside and that did not help it start, I get a temperature reading on the dash so I know that the sensor is working. This has generated a fault code due to being disconnected, had no other codes.
It does not start very well if the temperature is above 5 degree C, if it goes below 5 which it has only done once in the last two weeks it seem to start up ok.
Most of the test above was found by doing some googgling, I am thinking of going down the root of buying a new battery but I thought I would post to see if anyone could point me in the right direction.
Any help would be grateful
- She is due a cambelt change in just over 1K so would like to get it sorted before that is required,
- She is due an oil change around 3K, just had new fuel filter and has had a new air filter 9K ago.
- She also died completely 3 weeks ago so I have had the EDU (Electronic Diesel Unit) refurbished, when that was fitted she fired up ok, but she was having starting problem before she completely died. Yes common diesel pump failure problem, but according to the people I used these pumps are mechanically ok just the electronic part that is rubbish. Can post link to company website I used.
- Mileage 179K
- Fuel and economy is fine around 43-44 MPG
- Year 1998