View Full Version : bad starter and temp gauge not working

17-07-2010, 11:21 PM
Hi I wonder if anyone can help, I have just picked up a lovely low mileage 1994 2.0 litre A6 avant, but I am having a couple of problems,
Firstly the car is a very bad starter when cold, but once it warms up it starts first time. Also the temp gauge does not work, I was wondering is this anyway related.

17-07-2010, 11:59 PM
if this is not a wind up, you need a new temperature sensor fitting would be my advice.
i assume it's petrol? does it tick over at a steady rate?

18-07-2010, 08:36 AM
I was thinking it might be the sensor which is bolted to the head which was not working, but what is more of a problem is that the car is really hard to get started in the morning from cold, but once started and its been running its fine for the rest of the day,
I had the car serviced yesterday, with new plugs etc, but its still no better. it is a 2.0 litre petrol and once its been started and running it runs fine

Peter D
18-07-2010, 03:15 PM
The temp sensor is in the water way in the head and should be Cold - 560 ohms ‒ Hot - 58 ohms pin 3 to earth. However it would have to be stuck at 58 ohms or less to fool the cold fuelling. N17 cold start injector could be your problem, check reistance 8 to 15 ohms. I would check for a spark when cold cranking. Check inside the distributor that the sensor rotar is clean and the sensor is correctly positioned. Also check the resistance of the rotar arm 600 to 1400 ohms. Also check all plug caps resistance 4 to 6 k ohms cold. You had better tell us your engine code to go any further. Regards Peter

18-07-2010, 06:52 PM
Thanks peter I am not very mechanically minded,
I had the AA round today and they got it started for me as it wouldnt start this morning, He uncliped the the cold start injector sensor as the car was over-fueling.
He did seem to think that it was linked to the temp gauge not working, and it was down to one of two sensors.
There are two sensors next to each other one has three round pins and the other one has a blue clip on it, but I am not sure which one to change, also I am not sure what the sensor is called any ideas

Peter D
18-07-2010, 07:20 PM
The blue one is the cold start sensor. You need to PM me and I'll send you the test for this or post you email addess in your thread. Add a couple of spaces to avoid phishing. Regards Peter

18-07-2010, 07:44 PM
Thanks Peter that would be great, my email address is smugglersvin33 @ yahoo. co. uk

20-07-2010, 07:45 PM
I have just got bought the blue sensor so fingers crossed when it arrives that it works.
But it was cheap, as it was only a tenner with postage, so I thought I would give it a go.

Peter D
21-07-2010, 01:47 PM
But how do you know the sensor is duff. Did you test it. Regards Peter

21-07-2010, 06:29 PM
Hi Peter It was just that the AA mechanic was convinced that it was one of two sensors and not being very mechanically minded I decided to plump for the cheapest lol. It only cost 8 plus the postage.
I was just wondering how do I get the old one out, I notice it has a cir-clip round the sensor but I am not sure if I should pull the circlip together or push the cir-clip apart to release the sensor.
All I can make out is the cir-clip is the buried in a plastic sleeve with the ends showing, and don't want to break the clip as I don't have a spare.

21-07-2010, 06:49 PM
squeeze the clip together...and give the plug a wiggle.

Peter D
21-07-2010, 06:58 PM
To remove the sensor connector you press the wire clip in. To remove the sensor squire with WD40, press doen and remove the Clip. You will loose some coolant and do you have a new 'O' ring with the new sensor. Not aht I think it is the sensor that is at fault, have you check the cold sttart injector is not leaking. You AA guy report over fuelling not lack of fuel. Regards Peter

21-07-2010, 07:21 PM
Hi Peter, I am not optimistic about it working, especially as the car was over-fuelling on starting up, at the moment the car is running without the other blue sensor clipped in on the 5th injector for the cold start valve and its starting up ok. but it still doesnt have a gauge and obviously its still not running as economical as it should do.

Peter D
21-07-2010, 07:32 PM
Choke is hardly required this time of the year. Measure the resistance across the blue sensor terminal and tell me what you have. Also measure the resistance aforss the pins of the tmep sensor, the other one, then hot and tell me what you have. Regards Peter

21-07-2010, 07:45 PM
Hi Peter I am afraid I don't have a tester, my tool kit comprises of a couple of spanners and some cable ties lol.
I also have a old 1996 golf cabriolet which is so reliable, I think the only time I have lifted the bonnet on that car was to fill up the washer bottle lol.
That will teach me to go upmarket and buy and audi lol.
I am sure once the A6 is sorted it will be a lovely car.

Peter D
22-07-2010, 08:06 AM
For 10 or a digi from Maplin for a few quid more. Regards Peter

22-07-2010, 05:46 PM
I have managed to fix the car today and it now runs like a dream, first of all I changed the blue sensor which brought the revs down from 1100 rpm to around 800.
Then I put on the grey round 3 pin sensor which got the gauge working, so now I am over the moon with the car and it was all repaired for less than 25

Peter D
22-07-2010, 07:32 PM
An why was the grey connector not fitted before. Glad all is well. Regards Peter

22-07-2010, 08:05 PM
Hi Peter, well it ended up needing both sensors in the end anyway and the blue one did work a treat as it brought the revs back down and the fans kicked in, So I was going to leave it at that.
But I was so lucky as when I was doing the sensor my neighbour who works for the AA and is a fantastic auto electrician was driving past and stopped and had a look for me and told me straight away that if I want the gauge to work just change the 3 pin sensor, so I popped down to GSF and got myself one and now I have a lovely car which runs like a dream, I wouldn't mind but I have an 02 renault laguna sitting on my drive at the moment which belongs to my father and it feels like a complete wreck compared to the Audi.